I'm confused on how to tell if your lift pump is bad or if your injection pump is bad. I know if you install a fuel pressure gauge you can monitor the lift pump, but how do you tell if your injection pump is bad? I have read that just because your truck doesn't throw any codes doesn't necessarly mean your injection pump or lift pump is bad. Also, is dead peadle a sypmtom of a bad lift pump or injection pump.

Thank you

 

If you have good FP, you're sure the APPS is good, and you still have power loss or dead pedal, general consensus is that your injector pump is bad. You don't always get a code when the IP fails. I would pay the price to have the codes read on a good scanner...maybe even the dealer, before I sprung for a new IP.

 

Thank you for your response. Does anyone else have some more helpful tips. I'm trying to understand my truck better then I do and make sure that I become more educated on this engine so I know what to look out for and not get taken to the cleaners if I need to have it repaired. I am a rookie diesel owner and need all the help I can get.

Thank you

 

Do a search on how to reset your APPS. The APPS is the throttle position sensor and if it is going out you can get an intermitten dead pedal. This causes a similar symptom to a failing injection pump. Hard to tell without the computer throwing a code if in fact you do have good fuel pressure. My truck had a bad APPS and I thought for sure it was the injection pump but finally it threw a code. Eric

 

Thanks for the help. My truck did throw a code P0500 (No vehicle speed sensor signal) which kind of made sense since I did have a recent dead pedal incident. But there are no other codes. I need to do a search on how to reset the APPS. Thanks for the help and more suggestions are welcomed.

 

APPS Reset Procedure
Answer: This procedure has shown to help 24 valve ISB engines. It is basically teaching the fly by wire accelerator on these trucks to reread the position of the pedal and it's limits. Most complaints this will help with is poor acceleration, improper shifting, bucking in 5 and 6 speeds. Has been known to increase fuel mileage in some instances.

1. Set parking brake
2. Disconnect negative battery cables on both batteries
3. Turn ignition key to run(to drain any remaining capacitors)
4. Let truck sit for 30 minutes( this is the recommended minimum)
5. Return ignition to OFF position
6. Reconnect both batteries and secure, not a timed event
7. Turn key to run position(not start) and depress accelerator pedal slowly all the way to the floor
8. Allow pedal to return to top position slowly
9. Turn ignition switch OFF
10.Release parking brake
last updated 29.04.2006

 

Thank you crobtex for the APPS reset procedure. I actually did a search on and found the procedure. Probably was your post!

This is all great information and much appreciated. I don't know enough about these engines, but really want to become more educated. All your guys help is such a huge benefit to us rookies. I hope you guys will be patient with rookies like myself.

Thanks

 

Everyone here was a rookie at one time.

We're glad to help with what we can.