I had issues with warm starts. Ran just fine even after several hours of driving but if I turned it off and let it sit for a minute or two, it would refuse to start, didn't event attempt, besides cranking normally. I found out that my fuel rail was loosing pressure because quick connect fuel line o-rings were letting all the pressure leak out and suck air into the system which then caused vapor lock. Definitely need one of those gauges that connects to the schrader valve.
your fuel pump check valve is blown out. Get a check valve on your pump so your fuel doesn't flow back. You can put it up on the rail or on the outlet of the filter. Helps keep the pressure up and stable. Also change the lines to PTFE that get better pressure than those flimsy rubber lines.
My cold starts are instant but after it runs for a while, shut her down, she wont fire over unless it sits for ~15 min, then it will fire up ... And i DO have a Walbro 255 WITH the oem FPR ..
I’m gonna assume you have a truck style mounted on the rail for this explanation. When the membrane/diaphragm inside the regulator “blows out” it can leak fuel into the vacuum line connected to it. That’s another test actually, pull your vacuum line off the regulator with the engine off and hot. If you see or smell fuel - that’s most likely your problem. When you have a blown diaphragm and the vehicle can sit for awhile and get cold, the gas that leaked into your vacuum system can evaporate away. But when you hot restart it - that leaked fuel didn’t have a chance to dissipate and you’re left with a basically flooded engine. Press your pedal all the way to the floor while cranking and if does a hot restart quicker, that’s also another good sign you have a failed regulator. Look up “flood clear mode for a 5.3” for more info on that. Even if you don’t have a 5.3 all the ECUs basically respond the same.
@@MatthewFinlay those symptons sound about spot on literally .... If the car has been run or HOT, i shut it off, then it will NOT restart unless i wait ~10 min, then she fires right up ... Def sounds like fuel got released into the chamber and floods it out preventing start up, then if i wait 10 min, it dries out and it fires up fine ... Hmm .. i will check on that when i get home from work tonite ...
I'm having issues with my pressure gauge it's reading 60psi off. Have a new gauge to install but previous owner and I, of my gto are wondering if pressure regulator has gone out too.
@Mathew Finlay where can I purchase that gauge set up 1:48 with the built in valve inside the fitting, also be very helpful to know the size of the fuel pressure port, I have an 05 Chevy truck. Thanks!
And ironically I have a video about them too. They are specific to Ford, Chevy or Chrysler from an adapter standpoint but they all function the same. I’ve got two of them and both have worked great for years
A gauge attached to the fuel rail is worthless. You need a gauge fitting so you can hook up a pressure gauge that has a hose long enough to see while you are driving. Your fuel pressure can be fine when idling with the hood oped and drop dramatically under power when fuel demand is high.
my car does NOT have a schrader valve on the fuel HARD line and no rubber anywhere, its hardline from the fuel tank all the way to the fuel rail and hardline back to the tank ...
did you ever figure out the problem? I am having a similar issue with hesitation on warm starts ONLY. i just purchased fuel pressure gauge and adapter.
Yes - just needed a new regulator! Im trying an AC Delco this time to see if it lasts longer behind a Walbro 255 style pump. Is your issue on a truck engine (4.8, 5.3 or 6.0) or the Corvette style in the rear?
Comedic fuel gauge installation. Very good and don’t shake twice son.
I had issues with warm starts. Ran just fine even after several hours of driving but if I turned it off and let it sit for a minute or two, it would refuse to start, didn't event attempt, besides cranking normally. I found out that my fuel rail was loosing pressure because quick connect fuel line o-rings were letting all the pressure leak out and suck air into the system which then caused vapor lock.
Definitely need one of those gauges that connects to the schrader valve.
your fuel pump check valve is blown out. Get a check valve on your pump so your fuel doesn't flow back. You can put it up on the rail or on the outlet of the filter. Helps keep the pressure up and stable. Also change the lines to PTFE that get better pressure than those flimsy rubber lines.
My cold starts are instant but after it runs for a while, shut her down, she wont fire over unless it sits for ~15 min, then it will fire up ...
And i DO have a Walbro 255 WITH the oem FPR ..
To me that sounds like a classic case of blown out regulator!
I’m assuming we’ve got a LS engine but is it a truck style with the FPR on the rail or separate C5 style?
@@MatthewFinlay can you explain the technicality behind this ??
Why does it do that ?
I’m gonna assume you have a truck style mounted on the rail for this explanation. When the membrane/diaphragm inside the regulator “blows out” it can leak fuel into the vacuum line connected to it. That’s another test actually, pull your vacuum line off the regulator with the engine off and hot. If you see or smell fuel - that’s most likely your problem. When you have a blown diaphragm and the vehicle can sit for awhile and get cold, the gas that leaked into your vacuum system can evaporate away. But when you hot restart it - that leaked fuel didn’t have a chance to dissipate and you’re left with a basically flooded engine. Press your pedal all the way to the floor while cranking and if does a hot restart quicker, that’s also another good sign you have a failed regulator. Look up “flood clear mode for a 5.3” for more info on that. Even if you don’t have a 5.3 all the ECUs basically respond the same.
@@MatthewFinlay those symptons sound about spot on literally ....
If the car has been run or HOT, i shut it off, then it will NOT restart unless i wait ~10 min, then she fires right up ...
Def sounds like fuel got released into the chamber and floods it out preventing start up, then if i wait 10 min, it dries out and it fires up fine ... Hmm ..
i will check on that when i get home from work tonite ...
I'm having issues with my pressure gauge it's reading 60psi off. Have a new gauge to install but previous owner and I, of my gto are wondering if pressure regulator has gone out too.
@Mathew Finlay where can I purchase that gauge set up 1:48 with the built in valve inside the fitting, also be very helpful to know the size of the fuel pressure port, I have an 05 Chevy truck. Thanks!
Hey buddy here is a link to their website!
performancefuelsystems.com/serviceportkits.html
And ironically I have a video about them too. They are specific to Ford, Chevy or Chrysler from an adapter standpoint but they all function the same. I’ve got two of them and both have worked great for years
ruclips.net/video/UmSez0qvFn8/видео.html
A gauge attached to the fuel rail is worthless. You need a gauge fitting so you can hook up a pressure gauge that has a hose long enough to see while you are driving. Your fuel pressure can be fine when idling with the hood oped and drop dramatically under power when fuel demand is high.
I will do it to my car
Go for it buddy!
What are you working on??
@@MatthewFinlay Dodge charger 2017 RT 5.7
Nice! I believe they make this with a adapter for Dodge
How To Check Fuel Pressure The Easy Way - Performance Fuel Systems Gauge
ruclips.net/video/UmSez0qvFn8/видео.html
Links to parts used in description! Check out the written DIY here - www.garbagecharged.com/fuel-pressure-gauge.html
my car does NOT have a schrader valve on the fuel HARD line and no rubber anywhere, its hardline from the fuel tank all the way to the fuel rail and hardline back to the tank ...
did you ever figure out the problem? I am having a similar issue with hesitation on warm starts ONLY. i just purchased fuel pressure gauge and adapter.
Yes - just needed a new regulator! Im trying an AC Delco this time to see if it lasts longer behind a Walbro 255 style pump. Is your issue on a truck engine (4.8, 5.3 or 6.0) or the Corvette style in the rear?
Ls3 6.2 with corvette regulator
Cool did the problem start randomly one day or slowly overtime. Also is stock or tuned?
Randomly i think. The vehicle is tuned.
Whats the part number for the ac delco fuel pressure regulator