My mind was blown at 2:00. Yes, I am apparently an idiot, but at least I'm trying not to remain one :-). This was super helpful and to the point. Thanks!
I've been having problems with a GM 350 Ramjet crate engine installed in my 58 Apache. The thing is sluggish on acceleration and uphill. I scanned the engine using ScannerPro and found out the manifold pressure was too high under load and the spark advance was too high. I figured it was a vacuum leak and the base timing was off. I searched for a leak and the base timing was just fine. So, where do I go? I just put a pressure gauge on the EFI rail and found out the fuel pressure dropped from 39psi to about 35/36psi at cruising rpm (2000). Now that i watched this video, it makes sense now, the fuel pressure differential at high vacuum (lower psi on the rail) causes the engine to be sluggish on acceleration. The problem may not be the pressure regulator. But I darned sure understand the problem now. That will make it much easier to diagnose.
So the hose to the intake manifold connected to the regulator I’m guessing so that I’m not an idiot is a constant vacuum so that the vacuum decreases as I smash the throttle
Im sorry but when you connect the FPR to your engine you shouldnt connect the vaccuum line (yet) because you wouldnt be able to tell the actual fuel pressure coming from the pump if the manifold vaccuum is meddling with the fuel pressure when idling. So first you hook it up, check and set the pressure without the vacuum hose and THEN you connect the hose for a proper working FPR. Right?
See no reply. To bad that is a question I have. With the Vacuum line closed off 0 vacuum, that would be close to WOT. That would be where the most fuel is needed to reach the target A/F. At least that is how I see it. If you set the called for psi at idle when pressure drops the psi would go too high? Right. This is a NA engine.
Some systems had other ways of adjusting that and the fpr did not have a hose. So dont freak if yours does not. For some issues or to just give the car a bit of zip, one could up the fp a few psi. Fpr were on both electronic systems and mechanical fi systems.
Some fuel regulators are in the gas tank like in my ford explorer. Thus it has no vacuum line to adjust pressure. It uses a fuel pressure dampener instead.
So if you keep the vacuum line off and plug it will it make more pressure or less because I have a more high performance motor and I need a little extra pressure to my fuel rail and when I plugged the vacuum connector on the regulator it seemed to run better
Curently working on an NB miata The fuel pressure regulator is situated in the tank, and not connected to MAP It's suposed to regulate to a constant 3 bar The car had trouble starting, took a long time to start, then was running but really low on power... I've changed the pump because I suspected either the fuel regulator or the pump to be bad... The new pump is a high flow pump, not OE one . I was unable to find a fuel regulator (for a decent price that is, cause OEM part is almost worth the price of a decent aftermarket adjustable fuel regulator) The car now runs great, but I find the pump is a bit noisy (maybe because I didn't put panel and insulation back) I wonder if the pressure regulator is fine, or the new pump might just be sending enough pressure to compensate for a bad regulator, and will die soon if I keep runing it like that. My main questioning is, can I delete the OEM regulator and replace it with an aftermarket one, that would rather be in the engine bay, or next to the fuel tank (but not in)? If so should I run it to MAP (car is N/A but might be supercharged later so then obviously)? I don't know how the factory ECU works with the fuel pump but it feels like it's simply regulating pressure/flow by RPM thus increasing voltage output at the alternator and consequently at the pump... If I put a variable fuel regulator, I don't know how it would react...
Well if I say a fuel pressure regulator job is to keep a constant pressure difference between the fuel pressure and the intake manifold pressure then it will be correct. Having it set to 50 PSI fuel pressure, and when the intake manifold pressure goes to 20 PSI, the regulator will let the fuel pressure reach 70 PSI ?
@@EFIUniversity1 when the manifold pressure drop it means more air had entered... so the fuel need to add more pressure to meet the requirements for mixture??? did i get it right?
Ok good. I needed that. Today I found a teeny tiny vacuum line cracked on my gmc 5.3 that was sucking air. Trying to figure out it’s purpose. I finally got to understanding it to be the fuel pressure regulator vacuum line. So next I wanted to know if it mattered, that’s how I ended up here. Thanks. I will tape it up to repairs the crack for now, and replace it when I find a hose.
Actually...that is incorrect! You still want it connected, even for an NA vehicle, as long as the injector nozzle is referenced to manifold pressure! Otherwise the injector will flow more than it's rated and will skew your table values when tuning at low manifold pressures!
@@EFIUniversity1 that is not correct when you are na you're manifold pressure stays at 14.7 the entire time It does not change only in a boost application does the manifold pressure change. That is why on a NA vehicle you have a single inline fuel pressure regulator that regulates the fuel to whatever the manufacturer is asking if you rev up the engine your fuel pressure stays the same The only time it changes is when you go into boost so yes you're wrong. If you were correct on that then every vehicle from the factory would have an adjustable fuel pressure regulator on a NA vehicle and they do not they have a single between 35 to 60 PSI whatever the engine requires to be at 14.7
Nice, brilliant technical introduction to differential fuel pressure and how it relates to dynamic engine loads 🙌🏼 This is a fundamental concept and your delivery was spot on for all levels 👌🏻 P.S. Love the engine simulator and gold box being used for your flow bench rig, would have been even better to see what fuel flow meter you were using 😊
solid video really explains a lot. I am building a 1992 Celica with a Turbo charged 5SFE engine, i'm going to be using a Haltech elite 1500 to run it with 550cc injectors, walbro 255lph pump. Should be i looking at an AFPR too or will i be able to program this variable through Elite 1500?
Nice video, question, so I have just got a car, and the vacuum hose from the manifold isn't connected to the fuel regulator, and the that small connection on the fuel regulator leaks small amounts of fuel, it also sits at 50psi all the time. The car runs rich and can't hold a steady idle until it's warm. I assume the regulator is busted as fuel shouldn't come from that side connection and will need replacing, at which point I can connect the manifold vacuum tube and that should remedy in some way the rich running? Am I on the right track? This is my first car that I'm tinkering with so it's a steep learning curve!
If you don’t have or lose vacuum to the regulator would that let the engine crank and start but die immediately after? My engine will crank and start but dies immediately but I lost vacuum with the line.
If your a high HP application this set up will destroy your motor…. FPR after the fuel rails. The fuel pump should be supplying straight to the rails.. then be regulated after
I think it depends on the car. Mine is between the fuel pump and rail (mounted in the engine bay). At prime (ignition on) it maintains pressure on the rail for starting. This is a returnless system though.
my car will not run at all itll start and idle insanely bad for a few minutes then come outta it some times but something ive noticed is when it does run it misfires and has very poor throttle response pump works fine but there is no gas coming outta the return line so could it be its not getting enough vacuum or its just comepletely locked up or something ive bought a new regulator fingers crossed this is it ive also changed the filter to no avail
Neat clip but fails to address NA applications. Not everything has a supercharger or turbo, what about NA applications? Is vacuum reference still required or not needed? Seems odd to leave NA applications out of the discussion entirely
Ok stupid question, I have an ls intake for a 4.8, the intake does not have the fuel pressure regulator nipple on it can I t into the nipple that the pcv valve comes off of?
What is not discussed as this does not apply to direct-injected engines. You leave that barb wide open, open to atmosphere that is. The commanded high pressure fuel pump controlled by the ECU will adjust the fuel pressure.
Not sure if you found your answer. You will need higher rated injectors so 1) they’re not running as hard and 2) they’re actually pushing out enough fuel to combust in the amount of air being supplied. Just limiting the fuel pressure will only make it either idle rough or stall
fuel pressure regulator BEFORE or AFTER the fuel rail?? i thought the injectors need a specific fuel pressure to work properly, therefore the fuel pressure regulator (fpr). Now I was told that you should install the fpr after the fuel rail....that would put as much pressure on the injectors as my fuel pump can do - which in most cases is way too much??
I get F1007 and F1014 codes still searching what they mean. Somebody suggesting it may be crankshaft or timing issue, maybe crankshaft sensor, but I doubt car could be out of timing as it was not opened. Someone suggesting it’s a fuel problem perhaps too much fuel. It’s a Peugeot 207, any idea where to start?
Do a plug test! I just found out that method and was blown away, now just have to get a few sets of plugs An some hacksaw blades I plan on doing this on my 90 celica I've got a new set of injectors from 210cc to 220cc on stock engine management :( running super rich so hopefully this will be my answer to finding a little bit better tuneability with future na modifications
If I have a slightly bigger fuel pump than stock, something like a 255... Would that make my stock fuel injectors leak... And if the answer is yes, could a fuel pressure regulator correct this problem...
I need to replace my fuel filter in my Polo. I have two options: one without an integrated pressure regulator (cheaper) and one with. Which one should I buy?
that doesnt work on stock ecu tunes that run in static/closed loop, even with a return line. i drive an srt4 and have the FPR nipple un-plumbed until i get a tune where the fuel trim is adjusted, til then, the mopar ecu handles those parameters just fine for me and theres no need for a boost or vac reference.. the pump is a walbro 255 also, so im not pushing the pump to its limits either, something else to consider..btw, the srt4 guy i took my car to for the custom fuel setup, told me that himself and FWD here in houston has a very highly respected reputation, until you get a CUSTOM TUNE, theres no need to hook up a vac/boost source
I know this is an old post.. couple days ago I installed a 255 fuel pump kit and the apg fuel regulator return kit in my srt4. In high boost it cuts out. I haven't hooked up the vacuum to the regulator, I was hoping that was my problem and was gonna try hooking up vacum tomorrow. I haven't had it tuned yet. Was your cutting out in wot without vacum?
@@flahardwood not until i started getting tuned. Once i had a custom tune flashed, the car was overboosting like crazy, i ended up getting an agp adjustable wga, same prob. Either laggy as hell or too mich boost. Still havent figured it out yet. And im on vac ref now, but it did it on boost ref too
@bigmofoturbo86 I also installed the apg waste gate and a turbobay 2.5 bws. Did u get a 3 bar map and tip sensor? I purchased but won't be installed till tune. Maybe that will fix it, maybe u need same thing..idk.
@@flahardwood yea i got the 3bar map and tip, and pump rewire/bottleneck fix. I must have a vac line that needs to be checked. Or a boost leak test might help. Im bout to get it running again soon, needs new batt and is being shipped, ill try to remember to update yall once i get it figured out. I got mario tuning it for me, but i think his patience is runnin low with me lol. Just not a good time to prioritize my car right now, my dad had a heart attack, then after recovering from that, had vocal chord cancer. Is in the process of recovering from that now after 35 radiation treatments, then my uncle dies abt a month ago, work has been crazy, i mean.. i have legit excuses here but i kno hes gotta be tired of hearing them from me =/ i just want my car riding good again.
@bigmofoturbo86 sorry to hear about your father, family definitely comes 1st. And good luck with the car. I been working on mine for awhile,she is getting close
I still don't understand why the fuel pressure regulator is connected to the intake manifold by the vacuum line... there's a pressure sensor in the intake manifold, couldn't the ecu just read that and tell the fuel pressure regulator what to do? Or is it the case here that the fuel pressure regulator determines the pressure by itself via the vacuum line without any input from the ecu?
@@turboroman The FPR is a valve, those can be electronically controlled easily enough. The ECU controls plenty of other things this way. Kind of like how some EGR valves are opened via a vacuum diaphragm, and some are fully electronic. I'm curious as to why they don't use the electronic method here.
@@PeterB12345 they just used the so far much more common type of FPR. I know about the modern electronic ones. But this video covers the "analog" type. The vacuum reference port is there to keep the differential pressure constant during all engine load conditions.
@@turboroman Thanks for that, I didn't know there were fully electric ones. I was just wondering about the design choice when so many other things seem to be electric. I guess that's kind of a trend then... "Let the intake manifold vacuum actuate it" is turning into let the ECU control it via sensor input. But this is happening over time, not all at once.
My guess is the injector nozzle.. they probably test and select nozzle design to optimize atomization at a given pressure differential between manifold pressure to fuel pressure..
Nimbus Nimbus well from hearsay this description of adding vacuum source applies to the boosted engines. I have been told I do not need it in my naturally aspirated 2 stroke with external regulator and I can simply leave the vacuum on the external regulator open to atmosphere and not plugged.
does the fuel regulator need hold pressure at prime to 40+psi and suppose to hold at 40+psi ? or is it ok to go to 0psi after prime but no full ignition - is this a cause of a leak down bad regulator not holding pressure before ignition
I have a volkswagen polo 1.4 year 2000 the engine light warns me of code17559 does this include the fuel regulator i have change everything else in that code
Hello from Argentina! Great video! Just to check if I got it right. FPR is not there to assure constant pressure on the fuel rail but to assure you have a constant dP across the injector (between intake manifold and fuel rail). I assume that's because when you get an injector, the flow spec (let's say 250cc/min) is given at a constant dP (let's say 3 bar) and if for example in the case the throttle is closed you'll get a higher dp and that means higher fuel flow on the same injection time. Please say I'm right up to now. So.. I first want to say that I'm really new on EFI, I'm trying to learn to convert an old carburator car and I know I can really sound like an idiot with my question.. but what I don't understand and I would really appreciate your comments is what about the regulator without the vacum/boost port? is there any way to compensate with tunning? For ex on the same case I comented above (closed throttle) lowering injection time? Thanks in advance!
The old D Jetronic Mercedes use a fuel pressure regulator without a vacuum boost port. In this case, the FPR is designed to keep the pressure constant at 2 bar. There is however the crucial MAP (maximum absolute pressure sensor) which senses manifold vacuum and feeds this info back to the ECU which in turn tells the injectors when the fire. Mike
Do all engines require manifold pressure compensation? I have a naturally aspirated, throttle body injected engine and have always run the compensation port on the regulator open to atmosphere. My FP regulator is installed on the return line to the tank, not on the pressure line from the pump. With oxygen sensor in the exhaust controlling AF ratio, how would manifold pressure compensation help me?
im confused about this one too... i have m52 engine and im doing ccv delete and i have no clue if i can run the fpr open or not because currently its connected to my ccv not directly to intake manifold.
Shouldn't the title be "Understanding how a Boost reference fuel pressure regulator works". A real explanation of how the regulator works would be talking about the valve and spring that help regulate pressure.
So just to sound like an idiot... Your video actually told me what a fuel pressure regulator's job is and what it does but not , you know... How it works. Please correct me if im wrong i am learning this stuff as fast as RUclips can teach me
My mind was blown at 2:00. Yes, I am apparently an idiot, but at least I'm trying not to remain one :-). This was super helpful and to the point. Thanks!
Depends on if your pcm is set for vacuum/boost reference in the injector flow table to wether you connect the vacuum line or not
So... Relatively speaking it does keep the fuel pressure constant, as a function of the manifold air pressure variable? Loving these videos so much.
Yes but only the correct amount lol
Studying for the army’s asvab auto&shop portion of the test. This helps me put what I read into pictures. ❤
I've been having problems with a GM 350 Ramjet crate engine installed in my 58 Apache. The thing is sluggish on acceleration and uphill. I scanned the engine using ScannerPro and found out the manifold pressure was too high under load and the spark advance was too high.
I figured it was a vacuum leak and the base timing was off. I searched for a leak and the base timing was just fine. So, where do I go?
I just put a pressure gauge on the EFI rail and found out the fuel pressure dropped from 39psi to about 35/36psi at cruising rpm (2000).
Now that i watched this video, it makes sense now, the fuel pressure differential at high vacuum (lower psi on the rail) causes the engine to be sluggish on acceleration.
The problem may not be the pressure regulator. But I darned sure understand the problem now. That will make it much easier to diagnose.
So the hose to the intake manifold connected to the regulator I’m guessing so that I’m not an idiot is a constant vacuum so that the vacuum decreases as I smash the throttle
Im sorry but when you connect the FPR to your engine you shouldnt connect the vaccuum line (yet) because you wouldnt be able to tell the actual fuel pressure coming from the pump if the manifold vaccuum is meddling with the fuel pressure when idling. So first you hook it up, check and set the pressure without the vacuum hose and THEN you connect the hose for a proper working FPR.
Right?
See no reply. To bad that is a question I have. With the Vacuum line closed off 0 vacuum, that would be close to WOT. That would be where the most fuel is needed to reach the target A/F. At least that is how I see it. If you set the called for psi at idle when pressure drops the psi would go too high? Right. This is a NA engine.
Some systems had other ways of adjusting that and the fpr did not have a hose. So dont freak if yours does not. For some issues or to just give the car a bit of zip, one could up the fp a few psi. Fpr were on both electronic systems and mechanical fi systems.
eg D Jetronic Mercs dont have vacuum hose on the FPR.
Some fuel regulators are in the gas tank like in my ford explorer. Thus it has no vacuum line to adjust pressure. It uses a fuel pressure dampener instead.
can you show it in/on the vehicle instead of the bench mockup?
Heres a good explanation of what's happening directly on the car in terms of pressures ruclips.net/video/qO8z8cpp77g/видео.html
So if you keep the vacuum line off and plug it will it make more pressure or less because I have a more high performance motor and I need a little extra pressure to my fuel rail and when I plugged the vacuum connector on the regulator it seemed to run better
Curently working on an NB miata
The fuel pressure regulator is situated in the tank, and not connected to MAP
It's suposed to regulate to a constant 3 bar
The car had trouble starting, took a long time to start, then was running but really low on power...
I've changed the pump because I suspected either the fuel regulator or the pump to be bad...
The new pump is a high flow pump, not OE one .
I was unable to find a fuel regulator (for a decent price that is, cause OEM part is almost worth the price of a decent aftermarket adjustable fuel regulator)
The car now runs great, but I find the pump is a bit noisy (maybe because I didn't put panel and insulation back)
I wonder if the pressure regulator is fine, or the new pump might just be sending enough pressure to compensate for a bad regulator, and will die soon if I keep runing it like that.
My main questioning is, can I delete the OEM regulator and replace it with an aftermarket one, that would rather be in the engine bay, or next to the fuel tank (but not in)?
If so should I run it to MAP (car is N/A but might be supercharged later so then obviously)?
I don't know how the factory ECU works with the fuel pump but it feels like it's simply regulating pressure/flow by RPM thus increasing voltage output at the alternator and consequently at the pump...
If I put a variable fuel regulator, I don't know how it would react...
Got a new subscriber as soon as you mentioned the title. I need this, quick and to the point, How not to be an idiot.
Well if I say a fuel pressure regulator job is to keep a constant pressure difference between the fuel pressure and the intake manifold pressure then it will be correct.
Having it set to 50 PSI fuel pressure, and when the intake manifold pressure goes to 20 PSI, the regulator will let the fuel pressure reach 70 PSI ?
correct
@@EFIUniversity1
when the manifold pressure drop it means more air had entered...
so the fuel need to add more pressure to meet the requirements for mixture???
did i get it right?
Ok good. I needed that. Today I found a teeny tiny vacuum line cracked on my gmc 5.3 that was sucking air. Trying to figure out it’s purpose. I finally got to understanding it to be the fuel pressure regulator vacuum line. So next I wanted to know if it mattered, that’s how I ended up here. Thanks. I will tape it up to repairs the crack for now, and replace it when I find a hose.
The vacuum line is only on boosted applications that is the boost reference you do not hook that up on a naturally aspirated vehicle.
Actually...that is incorrect! You still want it connected, even for an NA vehicle, as long as the injector nozzle is referenced to manifold pressure! Otherwise the injector will flow more than it's rated and will skew your table values when tuning at low manifold pressures!
@@EFIUniversity1 that is not correct when you are na you're manifold pressure stays at 14.7 the entire time It does not change only in a boost application does the manifold pressure change. That is why on a NA vehicle you have a single inline fuel pressure regulator that regulates the fuel to whatever the manufacturer is asking if you rev up the engine your fuel pressure stays the same The only time it changes is when you go into boost so yes you're wrong. If you were correct on that then every vehicle from the factory would have an adjustable fuel pressure regulator on a NA vehicle and they do not they have a single between 35 to 60 PSI whatever the engine requires to be at 14.7
@@MrYukon04 why don't you tell Ford that.
Nice, brilliant technical introduction to differential fuel pressure and how it relates to dynamic engine loads 🙌🏼 This is a fundamental concept and your delivery was spot on for all levels 👌🏻
P.S. Love the engine simulator and gold box being used for your flow bench rig, would have been even better to see what fuel flow meter you were using 😊
solid video really explains a lot. I am building a 1992 Celica with a Turbo charged 5SFE engine, i'm going to be using a Haltech elite 1500 to run it with 550cc injectors, walbro 255lph pump. Should be i looking at an AFPR too or will i be able to program this variable through Elite 1500?
Nice video, question, so I have just got a car, and the vacuum hose from the manifold isn't connected to the fuel regulator, and the that small connection on the fuel regulator leaks small amounts of fuel, it also sits at 50psi all the time. The car runs rich and can't hold a steady idle until it's warm. I assume the regulator is busted as fuel shouldn't come from that side connection and will need replacing, at which point I can connect the manifold vacuum tube and that should remedy in some way the rich running? Am I on the right track? This is my first car that I'm tinkering with so it's a steep learning curve!
Is the vacuum connection also necessary for carburetor applications?
Thank you please show more when it's working on the test bench
This was great. Thank you. Much informtive, very help.
If you don’t have or lose vacuum to the regulator would that let the engine crank and start but die immediately after?
My engine will crank and start but dies immediately but I lost vacuum with the line.
Whats a fuelplumb?
Haha :)
No seriously good video... looking forward to the next one
It is what you make of it ;)
If your a high HP application this set up will destroy your motor…. FPR after the fuel rails. The fuel pump should be supplying straight to the rails.. then be regulated after
I thought the FPR should be mounted after the fuel rail, not before it (as you have it).
I think it depends on the car. Mine is between the fuel pump and rail (mounted in the engine bay). At prime (ignition on) it maintains pressure on the rail for starting.
This is a returnless system though.
Dumb Question: I only have a carburetor, no ECM or any type of boost.
Still connect hose to intake manifold?
Short and informative. Thats how we like it. Great ideer 👍😉
So what should the PSI read on the FPR for my TBI at idle on my 1995 GMC K-1500 with 5.7 Litre?
This excellent video definitely helped my idiot-itis symptoms!
my car will not run at all itll start and idle insanely bad for a few minutes then come outta it some times but something ive noticed is when it does run it misfires and has very poor throttle response pump works fine but there is no gas coming outta the return line so could it be its not getting enough vacuum or its just comepletely locked up or something ive bought a new regulator fingers crossed this is it ive also changed the filter to no avail
Neat clip but fails to address NA applications. Not everything has a supercharger or turbo, what about NA applications? Is vacuum reference still required or not needed? Seems odd to leave NA applications out of the discussion entirely
Does the same rule apply with a carburetor? Do I run a line from the regulator to the intake? I was curious where that went coming off the regulator
Why does some vehicles have a solenoid in between the manifold intake and fuel pressure regulator?
Ok stupid question, I have an ls intake for a 4.8, the intake does not have the fuel pressure regulator nipple on it can I t into the nipple that the pcv valve comes off of?
Nice work, one question, is there fuel pressure regulator for turbo aplication only? or all the same to non and with turbo aplication?
What is not discussed as this does not apply to direct-injected engines. You leave that barb wide open, open to atmosphere that is. The commanded high pressure fuel pump controlled by the ECU will adjust the fuel pressure.
So, in boosted applications, would you need higher rated fuel injectors? Or does the fpr compensating fuel pressure completely solve the issue?
Not sure if you found your answer. You will need higher rated injectors so 1) they’re not running as hard and 2) they’re actually pushing out enough fuel to combust in the amount of air being supplied. Just limiting the fuel pressure will only make it either idle rough or stall
Wait, how come in my car the FPR is located passed the fuel injectors? 1991 Honda accord
If u have fuel in the hose between the intake manifold and FPR does that mean FPR is bad
Well ok. How does it work with a carbonater. Not everyone has fuel ejection.
I once saw somebody installing this in a diesel om606 engin what’s the use since you don’t have any vacuum
Is it the same for a carbureted engine as it is for one with injectors ?
carbureted doesnt need one cuz it only need a fuel pump just to fill up tha carb but not needing much pressure to supply
fuel pressure regulator BEFORE or AFTER the fuel rail??
i thought the injectors need a specific fuel pressure to work properly, therefore the fuel pressure regulator (fpr). Now I was told that you should install the fpr after the fuel rail....that would put as much pressure on the injectors as my fuel pump can do - which in most cases is way too much??
they really need to be specific...
cuz diff engine size requires diff amount of supply in an specific pressure...
Here's a good explanation of different setups - skip to 6 : 23 ruclips.net/video/qO8z8cpp77g/видео.html
How does this differ in a DI car?
Already set my base fuel pressure. Do I need to hook up boost reference vacuum, if I'm N/A.?
yes!
I get F1007 and F1014 codes still searching what they mean. Somebody suggesting it may be crankshaft or timing issue, maybe crankshaft sensor, but I doubt car could be out of timing as it was not opened. Someone suggesting it’s a fuel problem perhaps too much fuel. It’s a Peugeot 207, any idea where to start?
Do you recommend a fuel pressure regulator on every engine?
I'm planning to install one on my motorcycle. But I don't see if it would benefit.
Do a plug test! I just found out that method and was blown away, now just have to get a few sets of plugs An some hacksaw blades I plan on doing this on my 90 celica I've got a new set of injectors from 210cc to 220cc on stock engine management :( running super rich so hopefully this will be my answer to finding a little bit better tuneability with future na modifications
If I have a slightly bigger fuel pump than stock, something like a 255...
Would that make my stock fuel injectors leak...
And if the answer is yes, could a fuel pressure regulator correct this problem...
I need to replace my fuel filter in my Polo. I have two options: one without an integrated pressure regulator (cheaper) and one with. Which one should I buy?
They both do the same thing just get the one with out it’s just a basic filter it’ll do you fine
Can anyone help the original mercedes e190 w201 is crazy money can I use anything else
Does fuel run through the top portion of the regulator? Mine has a pin hole in the top. Debating on hooking it up or getting another
that doesnt work on stock ecu tunes that run in static/closed loop, even with a return line. i drive an srt4 and have the FPR nipple un-plumbed until i get a tune where the fuel trim is adjusted, til then, the mopar ecu handles those parameters just fine for me and theres no need for a boost or vac reference.. the pump is a walbro 255 also, so im not pushing the pump to its limits either, something else to consider..btw, the srt4 guy i took my car to for the custom fuel setup, told me that himself and FWD here in houston has a very highly respected reputation, until you get a CUSTOM TUNE, theres no need to hook up a vac/boost source
I know this is an old post.. couple days ago I installed a 255 fuel pump kit and the apg fuel regulator return kit in my srt4. In high boost it cuts out. I haven't hooked up the vacuum to the regulator, I was hoping that was my problem and was gonna try hooking up vacum tomorrow. I haven't had it tuned yet. Was your cutting out in wot without vacum?
@@flahardwood not until i started getting tuned. Once i had a custom tune flashed, the car was overboosting like crazy, i ended up getting an agp adjustable wga, same prob. Either laggy as hell or too mich boost. Still havent figured it out yet. And im on vac ref now, but it did it on boost ref too
@bigmofoturbo86 I also installed the apg waste gate and a turbobay 2.5 bws. Did u get a 3 bar map and tip sensor? I purchased but won't be installed till tune. Maybe that will fix it, maybe u need same thing..idk.
@@flahardwood yea i got the 3bar map and tip, and pump rewire/bottleneck fix. I must have a vac line that needs to be checked. Or a boost leak test might help. Im bout to get it running again soon, needs new batt and is being shipped, ill try to remember to update yall once i get it figured out. I got mario tuning it for me, but i think his patience is runnin low with me lol. Just not a good time to prioritize my car right now, my dad had a heart attack, then after recovering from that, had vocal chord cancer. Is in the process of recovering from that now after 35 radiation treatments, then my uncle dies abt a month ago, work has been crazy, i mean.. i have legit excuses here but i kno hes gotta be tired of hearing them from me =/ i just want my car riding good again.
@bigmofoturbo86 sorry to hear about your father, family definitely comes 1st. And good luck with the car. I been working on mine for awhile,she is getting close
I still don't understand why the fuel pressure regulator is connected to the intake manifold by the vacuum line... there's a pressure sensor in the intake manifold, couldn't the ecu just read that and tell the fuel pressure regulator what to do? Or is it the case here that the fuel pressure regulator determines the pressure by itself via the vacuum line without any input from the ecu?
Do you think the ECU has an auxiliary mouth in the engine bay to tell the FPR what to do?
@@turboroman The FPR is a valve, those can be electronically controlled easily enough. The ECU controls plenty of other things this way. Kind of like how some EGR valves are opened via a vacuum diaphragm, and some are fully electronic. I'm curious as to why they don't use the electronic method here.
@@PeterB12345 they just used the so far much more common type of FPR. I know about the modern electronic ones. But this video covers the "analog" type. The vacuum reference port is there to keep the differential pressure constant during all engine load conditions.
@@turboroman Thanks for that, I didn't know there were fully electric ones. I was just wondering about the design choice when so many other things seem to be electric. I guess that's kind of a trend then... "Let the intake manifold vacuum actuate it" is turning into let the ECU control it via sensor input. But this is happening over time, not all at once.
My guess is the injector nozzle.. they probably test and select nozzle design to optimize atomization at a given pressure differential between manifold pressure to fuel pressure..
Would the same apply to a naturally aspirated EFI 2-stroke In a jetski?
Nimbus Nimbus well from hearsay this description of adding vacuum source applies to the boosted engines. I have been told I do not need it in my naturally aspirated 2 stroke with external regulator and I can simply leave the vacuum on the external regulator open to atmosphere and not plugged.
Oh !!! this is vocabulary lessons.
does the fuel regulator need hold pressure at prime to 40+psi and suppose to hold at 40+psi ? or is it ok to go to 0psi after prime but no full ignition - is this a cause of a leak down bad regulator not holding pressure before ignition
What if you dont have an intake manifold?
Im not sure what are u talking here unless it is a coal powered car, 😂
@@makaupurple8242 1960s engine. No computer parts not sensors. No eca map. Just need an inline fuel regulator
I have a volkswagen polo 1.4 year 2000 the engine light warns me of code17559 does this include the fuel regulator i have change everything else in that code
Is this only for EFI
thank you
very good video my brother ..you would be a excellent instructor...i would definitely sign up for your class..
Hello from Argentina! Great video!
Just to check if I got it right. FPR is not there to assure constant pressure on the fuel rail but to assure you have a constant dP across the injector (between intake manifold and fuel rail).
I assume that's because when you get an injector, the flow spec (let's say 250cc/min) is given at a constant dP (let's say 3 bar) and if for example in the case the throttle is closed you'll get a higher dp and that means higher fuel flow on the same injection time.
Please say I'm right up to now.
So.. I first want to say that I'm really new on EFI, I'm trying to learn to convert an old carburator car and I know I can really sound like an idiot with my question.. but what I don't understand and I would really appreciate your comments is what about the regulator without the vacum/boost port? is there any way to compensate with tunning? For ex on the same case I comented above (closed throttle) lowering injection time?
Thanks in advance!
The old D Jetronic Mercedes use a fuel pressure regulator without a vacuum boost port. In this case, the FPR is designed to keep the pressure constant at 2 bar. There is however the crucial MAP (maximum absolute pressure sensor) which senses manifold vacuum and feeds this info back to the ECU which in turn tells the injectors when the fire. Mike
Nice sweet explanation.
Do all engines require manifold pressure compensation? I have a naturally aspirated, throttle body injected engine and have always run the compensation port on the regulator open to atmosphere. My FP regulator is installed on the return line to the tank, not on the pressure line from the pump. With oxygen sensor in the exhaust controlling AF ratio, how would manifold pressure compensation help me?
Boosted yes. NA not always, depending on the ECU. LS engines from the factory just run straight pressure.
im confused about this one too... i have m52 engine and im doing ccv delete and i have no clue if i can run the fpr open or not because currently its connected to my ccv not directly to intake manifold.
Finally explained ! big thanks
Great explanation, your the man
I didn’t get it. I thought i knew about fuel, now im scratching my head
Same here. The explanation is bad so that it is not understandable, at least for me.
Great Job..Ty.
This helped. Thank you
How come nobody explains where the fuel goes in/out on the regulator?
It varies depending on the system used.
Yeah cause I have qft and it has no inlet/outlet direction also has the manifold tube spot
I feel not so dumb now. Thanks EFI. Me no dumb dumb no more.
Do OEM manufactures compensate via ECM instead?
many of them do!
Weird though, because on a K20A engine swap it doesn't like having that vacuum connected; throws everything off so we just leave it off.
Thought he was going to show some examples instead of talking about it
It provides relative constant pressure.
The fuel plump.
NO ONE,
NO QUESTION IS DUMB!!!
Finally! thanks a lot!
If I put 50 pounds of boost to my engine it will blow up🤣🤣🤣
Thanks very helpful
Shouldn't the title be "Understanding how a Boost reference fuel pressure regulator works". A real explanation of how the regulator works would be talking about the valve and spring that help regulate pressure.
That part is common knowledge
I dont have a fuel plump
Come on guys this is simple
So just to sound like an idiot... Your video actually told me what a fuel pressure regulator's job is and what it does but not , you know... How it works. Please correct me if im wrong i am learning this stuff as fast as RUclips can teach me
Liked just for aesthetics alone
no pressure
Lol lol lol lol lol !!!!! Yo, did he jus say “ how not to be a nigga” 0:23 ? Lol lol lol lol !!!!!
And this only applies to returnless Fuel system in boosted engines
im confused... can i run my m52 engine without the fpr connected to intake manifold?
Just make a bloody diagram.
Excellent! Now has anyone directed you to any videos of how not to come across as a smug arrogant douchebag
This is negative and pretentious
Love the WRONG! Followed by something that isn't true all the time.
well this was a waste of time