Engine/Transmission (1998.5 - 2002) '02 Won't Idle

[JCreer]

Last week I had the injection pump and cam position sensor replaced and now my '02 engine won't idle. Every time the engine comes down to an idle it dies. The throttle position sensor was replaced a few months ago and the calibration checked out. We've verified there is no air in the fuel lines by using clear lines from the tank to the IP. We disconnected the Edge from the system with no change resulting. The Edge does make it easier to start the engine though! The stock lift pump delivers fuel to the IP at normal pressures(max 13 psi) at all rpms even at idle when it dies. However, the Edge readout indicates the lift pump will not pump up to 13 psi with a turn of the key, the engine has to be turned over a few times before the lift pump will deliver 13 psi. We get no trouble codes either on an analyzer or the dash readout. We're checking all major electrical connectors now. Does anyone have any other suggestions of how to find the culprit??

Thanks!

 

[SnoKing]

Injection pump is not timed right?

How many threads and answers do you want?

https://www.turbodieselregister.com/threads/249316-Air-in-Fuel-Line

SNOKING

 

[Gary - K7GLD]

Last week I had the injection pump and cam position sensor replaced and now my '02 engine won't idle. Every time the engine comes down to an idle it dies. The throttle position sensor was replaced a few months ago and the calibration checked out. We've verified there is no air in the fuel lines by using clear lines from the tank to the IP. We disconnected the Edge from the system with no change resulting. The Edge does make it easier to start the engine though! The stock lift pump delivers fuel to the IP at normal pressures(max 13 psi) at all rpms even at idle when it dies. However, the Edge readout indicates the lift pump will not pump up to 13 psi with a turn of the key, the engine has to be turned over a few times before the lift pump will deliver 13 psi. We get no trouble codes either on an analyzer or the dash readout. We're checking all major electrical connectors now. Does anyone have any other suggestions of how to find the culprit??

Thanks!

Any error codes?

Have you tried disconnecting both batteries for a few minutes, reconnecting them, then manually recalibrating the accelerator pedal itself?

 

[JCreer]

The mechanic that replaced the old one has done several and swears it's timed right! I need as many ideas as I can get because so far, nothing is curing the problem.

 

[JCreer]

No error codes any time! The analyzer indicates the accelerator position sensor is still in calibration (0.78v to 3.82v), but I'll check the calibration after disconnecting/reconnecting the batteries to see if that fixes the problem. We've don the final calibration with the accelerator pedal with no luck!

 

[Road Dog]

You can wire the VP-44 to idle without an ECM. That eliminates the ECM, Edge, throttle, and everything that isn't an injector pump.

 

[JCreer]

Sounds interesting, do you have a favorite, easy way to do that?

 

[SnoKing]

BlueChip diesel has the instructions on their web site!

http://www.bluechipdiesel.com/vp44diagnostichelp.html

HOT WIRE TEST - THE "FOR SURE TEST" TO DETERMINE IF THE VP44 IS WHY THE ENGINE WON'T START
It is very rare, but possible, for a problem with the wiring harness or the CAN Bus wires to prevent the engine from starting, so if you want to be 100% sure it IS the Injection Pump causing the no start, follow the following directions exactly, to be sure of not damaging a possibly good pump. This test POSITIVELY eliminates the possibility of overlooking an electrical problem caused by other components that could affect the start or run function of the VP44, as long as you have verified fuel delivery to the Injection Pump. Remove the electrical plug at the back of the Injection Pump and hot wire the pins on the pump as follows. Get two wires long enough to reach from the battery to the VP44. Install an INSULATED ¼ inch female spade connector onto one end of each wire. Connect one INSULATED connector to pin 7 on the pump, which is the pin on the BOTTOM row of the socket on the Injection Pump, closest to the engine, to preferably fused (10 amp is fine) positive battery power in the PDC (Fuse box under the hood), or directly to the positive battery terminal if you like to take risks!
Connect the other INSULATED connector to the pin directly above the previous connection, the top row of pins, the one closest to the engine, and attach the other end to battery ground. Now try to start the engine and if it doesn’t start, you absolutely positively 100% need an Injection Pump! If the engine starts this way but NOT with the big plug installed on the pump, you know there is something in the harness or CAN bus wiring to the ECM telling or causing the engine to not start. Call me for help if this is the case.

 

[JCreer]

The engine starts just not quite as good as prior to the IP replacement, but it won't idle! When you coast down to idle something is telling the IP to stop pumping fuel/shut off fuel. Simply bumping the lift pump with the key doesn't do it, you have to turn the engine over a few times to get the stock lift pump to produce 13 psi and then the engine starts okay. What's telling the IP to shut down at idle speed??

 

[JCreer]

Sorry for being gone so long, but decided to put a FASS LP in! That did the trick and I'm sure the stock LP was the cause of the IP going out. I think the stock LP was just delivering enough fuel to run at 10 to 13 psi, but not enough to cool/lube the old IP. The reason the engine died at idle was because even tho the TPS was calibrated right the ECM hadn't learned the throttle curve. I did the final calibration step of slowly pushing down and letting up the throttle pedal about 20 - 30 or more times and the truck didn't die when coasting to an idle again. The new FASS LP caused a hard hot start verified by disconnecting the new LP when hot and starting normal. I'll put a delay relay in the LP elec circuit ASAP to take care of the hard hot start!

Thanks for all the help everyone!

 

[Gary - K7GLD]

I did the final calibration step of slowly pushing down and letting up the throttle pedal about 20 - 30 or more times and the truck didn't die when coasting to an idle again.

YUP - and THAT was most likely the ACTUAL problem from the beginning - which was pointed out at the start of this thread in post #3:

Have you tried disconnecting both batteries for a few minutes, reconnecting them, then manually recalibrating the accelerator pedal itself?

As to adding an aftermarket LP being the "final cure", unless the old one was totally shot and actually blocking fuel flow - hardly likely if the engine ran fine at fuller throttle application, only stalling at idle - chances are the new LP was not needed - many of these engines have run for thousands of miles with failed LPs not doing any pumping at all, as owners discovered only after checking with an external PSI gauge and discovering the LP was shot, and likely HAD been for quite a while...

 

[SnoKing]

Or they change the FF and can get the new one primed!

 

[gtwitch]

Gary K7GLD where have you been-- haven't seen any comments or helpful suggestions from you for quite a while and miss our help!

gtwitch in wyoming George Twitchell K7NOI

 

[JCreer]

Yup, and I had to get the truck home so I could do it right! So, all I could do under the circumstances was repeat the final cal with the pedal and it fixed the idle problem! The old LP got unbelievably noisy through all of this, so I decided not to take a chance and replaced it with a FASS before I drove the truck across the state to home.

Thanks for your input!

 

[Gary - K7GLD]

Gary K7GLD where have you been-- haven't seen any comments or helpful suggestions from you for quite a while and miss our help!

gtwitch in wyoming George Twitchell K7NOI

AH, been a number of things - lots fewer miles on the truck since moving up here to eastern Oregon, and fewer articles in the TDR mag related to my generation of trucks - plus, I took on a restoration of an old muscle bike from my earlier bike riding days:

That's an 1983 Kawasaki 1100 LTD, runs as good as it looks!

And finally, got tired of banging heads with one of the boards more vocally abusive members who had an opinion on everything - and wasn't the least bashful or tactful in exchanges with any who dared offer countering opinions...

Thankfully, he seems to have disappeared, so figured I'd check out the board, and see what's going on - thanks for your interest and comment.

 

[jeepit]

Good to hear and see you Gary!