Engine/Transmission (1998.5 - 2002) help truck wont start

[TDeltonto]

i have a 02 with a comp box, stage 3 jammer injecters, 95gph fass w/filters. about 6 months ago the truck wouldnt start when i was in town. i drove it to city market shut it off and bout 30 mins later tried to start it and it wouldnt start. i had fuel to the vp and had fuel out of the injecters. and the truck still wouldnt start so i let it sit for about an hour and it fired right up like it didnt have any problem. i drove the truck home and the next day it started and ran fine i shut it off three to four time and it started back up every time. but the next day it i drove it and it wouldnt start after i shut it off. i let it sit for an hour or so and it fired right up. so from there on i drove my other truck and let it sit but i went to drive it one night and it wouldnt start up. i tried every day for 2 weeks to start it and it wouldnt start so i took it to the mechanic and he said it was the vp. but i went to pull it home (cuz i didnt have the money for a new vp) and it fired right up so i drove it home from the mechanics. i have put a new cam shaft p/sensor, all the fuses are good, unplug the comp and still no change, i try to start it up every now and then and it doesnt usually start. i tried to start it last night and it wouldnt start (i have fuel coming out of the injecters and the fass cycles) but today it started and it runs great i drove it around town. i cant figure out how if the pump is bad why the truck runs so great and why it wont start. could it be a ground or ??? i have got a 1693 and a 1689 dtc by cycling the key but never a check engine light since the problem started. but i didnt have them cleared so any solutions would be greatly appreciated

 

[Andy Redmond]

I found a 99 with this symptom that had a bad ecm. The drivers that send 12 v from the ecm (differing pins) to the PDC fuel ip relay that allows for power at the IP connector (Pin 7) and the transfer lift pump fritzed out and wouldn't supply votage after the engine warmed up, then voltage would slowly drop to about 7-8 volts, the relay would open and the truck would die. It wouldn't recrank until it cooled off and/or sometimes when the battery - cables were disconnected.



Hope this is not your prob.



Do some through troubleshooting or have someone do it for you before changing out a lot of parts. . hoping to get it.



FWIW, I don't find too many failed ECM's, which can't be said for the IP and LP.



Good luck

Andy

 

[LowFly]

My first VP failed this way... ...



Here is one quick test you can try... BUT only do if you feel comfortable as it involves ether.



If the truck will not start, pull the cold intercooler pipe at the air horn. Disable the intake heater grid. Then just shoot a SMALL puff of ether up in the horn (Takes VERY little). If the truck starts right off... and does it every time when you perform this test, you might be looking at a VP. Someone told me it was due to a sticking solenoid in the pump that doesn’t allow pressure to build under low RPM of the pump to pop off the injectors... . thus a no start. With the ether, the RPM’s come up quick and overcome the bleed off and the truck starts and drives normal until its shut off again. Could also explain the random nature of your issue as well. (Mine was every time though and it would not start at all. ) I also never got a code when my issue took place…and new VP fixed it. Take it for what its worth.



NOW you can also start to clamp off lines to isolate air leaks as well... . that would also be a good test.

 

[TDeltonto]

thanks ill try it

 

[AllianceDiesel]

haha, now thats funny ether is my best friend in diagnostics, I have never had it explode on the intake heater, I have always sprayed it right into the intake tube on the turbo. (great way to bleed injectors on a 2nd gen if you don't have somebody to help)



see what that does

 

[LowFly]

haha, now thats funny ether is my best friend in diagnostics, I have never had it explode on the intake heater, I have always sprayed it right into the intake tube on the turbo. (great way to bleed injectors on a 2nd gen if you don't have somebody to help)



see what that does

I agree. Ether is a good tool..... if used wisely... .



I never did like spraying into the turbo for fear of a rare back fire that could damage turbo and intercooler... . and person! haha... .

 

[blacksheepdiesel]

Ether will not work unless the injection pump is putting in fuel.

Godspeed,
Trent

 

[TDeltonto]

tried a little ether through the turbo truck ran on ether but as soon as it burned it up it died. i cracked 3,4,5 injecters and they all have fuel coming out of them

 

[Andy Redmond]

Just becuase the VP44 will squirt fuel at the injector doesn't mean that it will do it at the proper time or will produce enough psi to fire the injector.



It sounds like VP44 time. You FIPM (fuel inj pump module) likely is toast.



Double ck. for 12v at pin 7 (red/light green tracer) of the IP elec. connector and good grd at pin 6 (black w tan tracer).



If not ok, temp. connect a power and grd to the pump with the IP connector removed, it should start and idle only. If not you have a elec. harness prob. or ECM prob.



Good luck

Andy

 

[LowFly]

Yup... that is the other side of the test... . sounds like you have catastrophic mechanical failure in your pump... . wont necessarily pop a code…but the ether will prove that…. check the pins as described above……sounds like a bad VP if you got fuel... but its not pulsing at the cracked lines... ...