Engine/Transmission (1998.5 - 2002) Gradual Power Loss

[DBuchheit]

I've been experiencing a gradual power (performance) loss over the last 6 months, maybe longer. I have replaced the IAT & MAP sensors as well as reset the APPS. None of these things have helped. I have an Edge EZ installed and have tried disconnecting it. The power does fall off even more without it, so it seems to be working. I have a full set of gauges, Boost, EGT and fuel pressure (lift pump) are all OK. Fuel economy has not fallen off, in fact it may be improving a little. That would lead me to believe that there are no issues such as compression loss. My fear is that the injection pump is slowly going south. It is the original with 96K miles on it.



Any thoughts or help would be appreciated.

 

[WardJ]

Any codes displayed? Mine did the same thing, then started getting a dead pedal from time to time.

 

[2-ND TIME]

power loss

Have you had the injectors tested? They are more likely wearing out, they maybe POPing at 2500 psi. Have the new ones tested if you find that they need to be changed out this will give you base line for future info.

 

[DBuchheit]

No codes, but thanks.

 

[rkressg]

How many miles on your truck?
Are you seeing any excessive smoke (more than normal)?

Your valves could need their lash adjusted. As the valves begin to move out of their tolerance range, performance begins to fail.

Also, change your fuel filters. You could be at the very early start of a failing VP44. Is your Airfilter clogged?
-Rich

 

[Mundgyver]

Ditto on the valves. Set them to mid specs and that will help. The other thing is what is your fuel pressure running at and when was last time you dumped in some fuel conditioner to clean up the injectors for soot on the tips and such.



Food for thought.