fuel system questions

[bagd99dak]

hey guys, just subscribed to the web site and am looking forward to learning some diesel stuff. so here i go already. i have an 05 3500 ctd with automatic. my question is about a fuel problem, because the truck has an intake and exaust along with boost, egt, and fuelpressure guages the dealer refuses to look at it. my engine lite come on only when i am towing a trailer. code p0148 (fuel delivery error). i just installed my fuel guage so not sure what it is supposed to read, i get about 10lbs but the thing is it stays their. even when truck is off. it can sit for a few hours not running, check the guage and still reads 10lbs of pressure. i know its not the guage cause if i unscrew the filter cap i can hear the pressure release and the guage goes back down, i was told this aint normal. is their somthing i should look at or test to see if their is a problem? is their a pressure releive valve or somthing not working, clogged line. also when light come on the trucks power takes a dive, bad, towing a 5k trailer on flat ground i was down to 40mph, nothing their at all, also when that happens the egt's went up to about 900-1000, usually runs about 700. any ideas. thanks guys.

 

[rbattelle]

Speaking from an '03 perspective, there was no drainback valve present, so my system actually does hold some pressure when it's off. But maybe in 2005 there is a pressure relief valve in the tank?



If you're getting 10lb of fuel pressure consistently when the light comes on, then fuel pressure is probably not your problem. It's possible the flow rate on the fuel pump is wrong, I suppose, although that's highly unlikely.



Are you running any performance boxes?



-Ryan

 

[bagd99dak]

no performace boxes, holding off on that for a while. truck only has 10400 miles. is the injection pump in the tank on the new cummins, if so. do they have a screen on the fuel line that can get clogged, that could be causing the problem perhaps. i am thinking of dropping my tank and taking a peek inside. anyone else have any ideas??

 

[tareynolds]

your fuel transfer pump would be in the tank, the injection pump is on the left side of the engine and is run from the cam gear. 10 psi is too low for that truck, the transfer pump runs, unlike the earlier models at 100% from key on, this is because of the very high pressures that the injection pump has to make, up to 26,000 psi. what kind of gauge are you using, and how is it fed, anti-freeze, or another liquid? I have had some problems on the newer trucks, let me know this info, and I can tell you what you need to know.

 

[rbattelle]

10 psi is too low for that truck

I disagree, I think 10psi is perfectly acceptable. Where's the spec that says 10psi is too low?



If the filter screen plugged up the fuel pressure would drop to 0 almost immediately if the engine were running at the time. If you're getting a fuel delivery error (and your lift pump is functioning normally) it's possible there's a problem with the low-pressure side of the injection pump; either the fuel control actuator or the LP injection "pre" pump itself.



Up through 2004 there was no real way for the engine to determine the activities of the LP fuel system (not sure if any were added as of 2004. 5... but I doubt it). My 2003 manual doesn't list P0148 as "Fuel deliver error", rather it's listed as HPCR Checksum. I think we decided awhile ago that was primarily caused by a faulty rail pressure relief valve. Faulty rail relief valves do exhibit the same sort of circumstances you describe...



-Ryan

 

[bagd99dak]

i have the issipro fuel guage with the isolater, isolater to guages is antifreeze like it says to use, to get the fuel pressure i bought the billet fuel filter cap, got everything from geno's garage.

 

[GWoody]

10400 miles, I'd try to find a different dealer, what part of the country are you in? Maybe someone on here knows of an understanding dealer.

 

[bagd99dak]

im out in the middle of long island, ny. i was talking to another dealer about the problem and he seemed ok. i told him the circumstances of the problem, only happens when towing a trailer and all. told him exactly what is done to the truck, he said that their is no problem with him bringing it into the shop to look at, but the engine lite is off again. but he said that when im hauling a trailer and it happens and im near the dealer to come by and he will send a mechanic out for a drive with me. also said that the only way an aftermarker part would be an issue is if it has a direct affect on the failed part. so he seams be alot nicer to work with then the other dealer. . but still looking for answeres as to what the real problem fuel problem could be. im sure eventually ill find it. or somthing will just totally break