Well, I messed up, I dropped the wrench while turning up the fuel and then bumped the nut. Idk how many times it went back. Guess I'll find out when I get my upper radiator hose. Either way, I drive like a grandma anyway and I got a EGT gauge. I shouldn't have to push it more anyways since hills & inclines are not an issue since Lake Charles is just flat besides the 210 bridge and I 10. I need to do the FDIC bypass next.
I’m about to increase fuel on my 5 ton and got some baseline EGTS today of around 1000 unloaded and 850-900 loaded. Thought it was odd that it ran cooler with a load. I’m hoping there’s plenty of room for fuel increase because it is an absolute dog anytime there’s a hill and have to drop to third every time. Still safety wired shut so I assume it’s never been messed with.
@@tacticalrepair of course! That makes sense, don’t know why I didn’t think of that. I turned my fuel up 2 flats today and noticed no noticeable difference and EGT remained the same but boost gauge was showing around 10psi on the C turbo. Not sure if I should continue increasing the fuel or have to lower the smoke cam first.
What you are forgetting is if the FDC is bypassed the FDC wedge plate is not longer moving. So that being the droop and smoke cam are not adjusted only the main fuel control. With the FDC bypassed and you set the main fuel control / twin nuts to you boost pressure you want then if you then go and change the droop or smoke cam all you are doing is changing your main fuel control setting. Yes for some reason your FDC is not bypassed we can adjust the droop.
Thank you for another awesome video. I need to check mine to see if it has been tampered with yet. But I did have a question. How common is it to find an LDS motor in an m35? I have a 1968 but the lower end was swapped in 75 and the injection pump says LDS on it
what does the FDC do to compensate for different fuels? (assuming that is it's purpose) Am brainstorming how to compensate for different fuel combustion characteristic on an old Mercedes diesel
It modulated input fuel via a piston in the compensator that is in turn modulated via a ramp that contacts the governor. They only regulated the amount of fuel and they didn't even do that well. It's entirely unnecessary for multifuel capability. That capability on these engines came from the piston bowl and swirl chamber design as well as the injector spray pattern and timing. The multifuel engines run just fine on everything even without the compensator. Most mechanical diesels will run on everything just as well, with the exception of gasoline. There's really no reliable way to make your engine burn gasoline, but it will burn everything else just fine. Basically alcohol, acetone, and gasoline is all you need to avoid. The multifuel won't burn alcohol or high octane gasoline either.
So what exactly does the smoke screw do? I have a C turbo and I turned up my (pump only) several years ago, I will be curious next time I drive it to keep it around 12 psi boost (since its a C turbo) and see what the pyrometer shows. Thanks, I really enjoy your video's, I can read steel soldiers all day and still be confused or sometimes more so or I can watch one of your instructional videos. I much prefer your videos. One last thing, after setting a C turbo to 12 psi boost and then making the smoke screw adjustment what is the new boost pressure or is it still 12 psi? Thanks Matthew
Matthew Jones You should set main fuel for no more than 8 psi boost, then use smoke cam adjustment to obtain a maximum of 12psi, or whatever your pyrometer allows. Every engine is different.
I have an lds465 1A and I deleted my FDC and left my fuel settings alone. I have added an Intercooler and it made about 10 or 11 lb of boost. At this point it drove pretty good except for I'd have to back out of the throttle to keep the egts low. I blocked off the wanna-be wastegate and now I'm getting about 16 pounds of boost and my egts are lower in fact I don't have to step out of the throttle at all they stay under 1200 all the time and tons more power. I know this may be outside the scope of what you normally have done but that one question I have is I get a lot of smoke under 1800 RPMs and I was wondering if I could back the droop screw off a little bit to compensate for that? Or is it better that I back off the main fuel and bump up the smoke cam like you have done?
I wouldn't touch the main fuel adjustment if you're already getting that with a C turbo. Maybe just adjust the smoke cam. But be careful. The C turbo doesn't move much air, and those turbos lead to a lot of melted pistons after fuel adjustment. If you don't have a pyrometer you should install a good one first so you can keep your engine alive.
Yes. I've always had to turn the fuel up after bypassing the FDC, but every truck is different and the amount depends on where you live. Needing to turn the fuel down after a bypass is a wife's tale in most cases.
Adjustment procedure is the same but you need to be careful. It is easier to melt pistons in a non turbo truck if you add more fuel without more air. You need a pyrometer.
This is a great break down comprehension. Thanks Garrett. Your a good instructor.
Well, I messed up, I dropped the wrench while turning up the fuel and then bumped the nut. Idk how many times it went back. Guess I'll find out when I get my upper radiator hose. Either way, I drive like a grandma anyway and I got a EGT gauge. I shouldn't have to push it more anyways since hills & inclines are not an issue since Lake Charles is just flat besides the 210 bridge and I 10. I need to do the FDIC bypass next.
I’m about to increase fuel on my 5 ton and got some baseline EGTS today of around 1000 unloaded and 850-900 loaded. Thought it was odd that it ran cooler with a load. I’m hoping there’s plenty of room for fuel increase because it is an absolute dog anytime there’s a hill and have to drop to third every time. Still safety wired shut so I assume it’s never been messed with.
You get more boost loaded so it leans the air fuel ratio out. You do have some room to work with.
@@tacticalrepair of course! That makes sense, don’t know why I didn’t think of that. I turned my fuel up 2 flats today and noticed no noticeable difference and EGT remained the same but boost gauge was showing around 10psi on the C turbo. Not sure if I should continue increasing the fuel or have to lower the smoke cam first.
appreciate the info ... I may have tto watch it a few times But great info!
What you are forgetting is if the FDC is bypassed the FDC wedge plate is not longer moving. So that being the droop and smoke cam are not adjusted only the main fuel control. With the FDC bypassed and you set the main fuel control / twin nuts to you boost pressure you want then if you then go and change the droop or smoke cam all you are doing is changing your main fuel control setting. Yes for some reason your FDC is not bypassed we can adjust the droop.
My FDC has been bypassed. Is there a similar adjustment on the injection pump? Also, do I need a pyrometer with a bypassed FDC?
Thank you for another awesome video.
I need to check mine to see if it has been tampered with yet. But I did have a question.
How common is it to find an LDS motor in an m35? I have a 1968 but the lower end was swapped in 75 and the injection pump says LDS on it
Not super common, but not unheard-of either. In later years some motor pools just installed whatever was available.
Great videos and very informative. Thanks
what does the FDC do to compensate for different fuels? (assuming that is it's purpose) Am brainstorming how to compensate for different fuel combustion characteristic on an old Mercedes diesel
It modulated input fuel via a piston in the compensator that is in turn modulated via a ramp that contacts the governor. They only regulated the amount of fuel and they didn't even do that well. It's entirely unnecessary for multifuel capability. That capability on these engines came from the piston bowl and swirl chamber design as well as the injector spray pattern and timing. The multifuel engines run just fine on everything even without the compensator.
Most mechanical diesels will run on everything just as well, with the exception of gasoline. There's really no reliable way to make your engine burn gasoline, but it will burn everything else just fine.
Basically alcohol, acetone, and gasoline is all you need to avoid. The multifuel won't burn alcohol or high octane gasoline either.
@@tacticalrepair what moves/changes the piston position? fuel viscosity?
So what exactly does the smoke screw do? I have a C turbo and I turned up my (pump only) several years ago, I will be curious next time I drive it to keep it around 12 psi boost (since its a C turbo) and see what the pyrometer shows. Thanks, I really enjoy your video's, I can read steel soldiers all day and still be confused or sometimes more so or I can watch one of your instructional videos. I much prefer your videos. One last thing, after setting a C turbo to 12 psi boost and then making the smoke screw adjustment what is the new boost pressure or is it still 12 psi? Thanks Matthew
Matthew Jones
You should set main fuel for no more than 8 psi boost, then use smoke cam adjustment to obtain a maximum of 12psi, or whatever your pyrometer allows. Every engine is different.
I have an lds465 1A and I deleted my FDC and left my fuel settings alone. I have added an Intercooler and it made about 10 or 11 lb of boost. At this point it drove pretty good except for I'd have to back out of the throttle to keep the egts low. I blocked off the wanna-be wastegate and now I'm getting about 16 pounds of boost and my egts are lower in fact I don't have to step out of the throttle at all they stay under 1200 all the time and tons more power. I know this may be outside the scope of what you normally have done but that one question I have is I get a lot of smoke under 1800 RPMs and I was wondering if I could back the droop screw off a little bit to compensate for that? Or is it better that I back off the main fuel and bump up the smoke cam like you have done?
@@jayj7997 Where did you put your intercooler?
I have a c turbo and I max out at about 9 to 10 psi. So can I just adjust the smoke cam up? or do I start the fuel screw first?
I wouldn't touch the main fuel adjustment if you're already getting that with a C turbo. Maybe just adjust the smoke cam. But be careful. The C turbo doesn't move much air, and those turbos lead to a lot of melted pistons after fuel adjustment. If you don't have a pyrometer you should install a good one first so you can keep your engine alive.
@@tacticalrepair what is a comfortable temp to keep at or below?
@@KraeseRepairs 1250 max preferably.
@@tacticalrepair thank you
@@tacticalrepair is it better to switch out to a d turbo?
After doing this for those of us that already have a Pyro and boost gauge. What a safe EGT range in 5th under load? For a D turbo.
Momentarily, 1350. Sustained, 1200
Doing this to the truck, is it still safe to run ot as a multifuel ? Waste oil, kerosene, ect ?
Yes
Mine runs great it just wont idle. Starts right up.
does any of this matter if you bypass the FDC
Yes. I've always had to turn the fuel up after bypassing the FDC, but every truck is different and the amount depends on where you live. Needing to turn the fuel down after a bypass is a wife's tale in most cases.
What about a non turbo
Adjustment procedure is the same but you need to be careful. It is easier to melt pistons in a non turbo truck if you add more fuel without more air. You need a pyrometer.
Maybe I should just leave it alone.