Now fuel pressure
#1
Now fuel pressure
I have a 94 chevy 1500 with a 6.5td. I have rebuilt plenty of gas motor but I have never worked on a diesel before.
A little background on the truck.
The truck sat for over a year with no fuel, a rodent built a nest under intake and chewd up my injector wiring harness along with a few other none related problems I already resolved.
I fixed the wiring harness and cleaned out the nest. The problem I'm having is I have a steady flow of fuel at the injectors but no pressure. The same at my fuel filter. When I turn the truck over I get a little white smoke and truck tries to fire but wont. I have already checked all the electrical. Lift pump, fuel solenoid and pdm all working and I cant find any line blockage.
What else could it be?
A little background on the truck.
The truck sat for over a year with no fuel, a rodent built a nest under intake and chewd up my injector wiring harness along with a few other none related problems I already resolved.
I fixed the wiring harness and cleaned out the nest. The problem I'm having is I have a steady flow of fuel at the injectors but no pressure. The same at my fuel filter. When I turn the truck over I get a little white smoke and truck tries to fire but wont. I have already checked all the electrical. Lift pump, fuel solenoid and pdm all working and I cant find any line blockage.
What else could it be?
#2
If its been sitting and you are trying to get it running i can almost gaurantee it needs a new set of glow plugs. last 6.5 i got had 7 that were burnt up and open. white smoke is a sign of low heat causing incomplete combustion. If the glow plugs arent burning you will just make white smoke. Glow plugs are REQUIRED to get a 6.5 running at any temperature.
#9
Whelp put glow plugs in went to crank and it just turned over didn't even try to fire. After looking over everything I found I need to re prime my fuel system. I just done it less than a weak ago but system full of air again . I got all the air out of the filter and at the solenoid but no fuel to the injectors. I get a little dribble at the number 2 injector that's it. Any one have an idea what could be causing air to get into my system. I don't want to re prime every time I let it sit a few days.
#10
if its draining back to the tank there is a line, seal somewhere letting air back into the fuel lines and it is gravity bleeding back to the tank. If it isnt a big enough leak to let fuel out this can be very difficult to find. Any time i take the intake off one i change all of the fuel hose that is under there, its only a couple feet. The injection pump on these is pretty simple so lets walk through the system cause it sounds like you need to start over. fuel starts at the tank and is pulled out by the lift pump (any air leaks here will cause poor lift pump performance or air ingestion while running), leaves there under pressure (around 5 psi average) and heads up to the fuel filter (where the lines cross over to the trans is a common leakage point but probably not yours). Next stop is the fuel filter and our first chance to bleed air out (this module may have several o-rings and seals which could be a location of your leak it also has the water drain which you see up by the alternator and the bleeder on top.). If it was me i would have the lift pump on a switch i controlled at this point so i could keep the system pressurized at all times (not just when you have oil pressure which makes bleeding the system difficult and hard on starter and glow plugs). To assist in looking for leaks you could cover all the lines in baby powder, pressurize it, and look for the baby powder to change (Works -sometimes).
Our next stop is the injection pump, we have a internal transfer pump in here that can pull fuel from the tank in a leak free system and keep the engine running. It supplies the high pressure side with about 120 psi fuel transfer pressure. It is a vane style pump and very very very rarely experience failure but we have no way to check it. next its into the plunger bores and out down the lines to the injectors.
having read that novel i have questions.
Is your lift pump hot wired?
Does it pump fuel out of the top of the fuel filter housing?
Are we sure there arent any codes stored in the ecu?
Your glow plugs are all good now, but did you check for power in the circuit while its intact/under load?
Are you trying to bleed the injectors with your foot all the way to the floor on the accelerator?
Mechanical issues like timing chain failure/bearing failure have been assumed ok up til now, do you have reason to believe the engine is ok?
Is it turning over fast enough (i know, scientific), and can you hear compression?
When the key turns on can you hear and feel the fuel shut off solenoid activate? does it have power?
Our next stop is the injection pump, we have a internal transfer pump in here that can pull fuel from the tank in a leak free system and keep the engine running. It supplies the high pressure side with about 120 psi fuel transfer pressure. It is a vane style pump and very very very rarely experience failure but we have no way to check it. next its into the plunger bores and out down the lines to the injectors.
having read that novel i have questions.
Is your lift pump hot wired?
Does it pump fuel out of the top of the fuel filter housing?
Are we sure there arent any codes stored in the ecu?
Your glow plugs are all good now, but did you check for power in the circuit while its intact/under load?
Are you trying to bleed the injectors with your foot all the way to the floor on the accelerator?
Mechanical issues like timing chain failure/bearing failure have been assumed ok up til now, do you have reason to believe the engine is ok?
Is it turning over fast enough (i know, scientific), and can you hear compression?
When the key turns on can you hear and feel the fuel shut off solenoid activate? does it have power?
Last edited by Josh Haynes; 05-11-2016 at 01:03 PM.