I need help with my 97 cummins , it has 280k miles still ran real good until lately the surge of boost is not there , I can't get rpms above 2000 under a load but I can get them if I gradually increase speed. I have recently replaced the lift pump because of noise and delivery problems, also have replaced the air filter thinking it was clogged but neither has helped .

 

Did you change out the fuel filter too?

 

I agree with Jake, change the fuel filter.

then check the tps, and injectors for clogs as last resort.

 

On this how often do you guys change your fuel filters? I've heard everything from every oil change to w/e you get a noticiable loss in fuel pressure....hoping to get somethin a lil more accurate!

 

Ichange mineevery other oil change which puts itat 10k miles

 

That sounds alot better! Will do...