Sluggish Acceleration Hummer H1 6.5 non turbo Diesel

[Roy]

Firstly, to get the truck moving, trany goes into gear. We just have no throttle response. Trany not a problem till we get the rpm's going on the motor.
Second we need to address the hard shifting issue--TPS
 
 The next step is to check a valve on the injection pump for being stuck. Its located under the throttle shaft and rubs on a cam.
This  valve controls throttle response. If it is seized, new or rebuilt injection pump. I have an used pump off a 6.2 NA to test if needed.

[Skenth]

It's way over my head. I'll keep u posted on when it's coming over!

[Skenth]

Tps changed. ..no change. Still not getting throttle response in gear. Revs perfectly in neutral or park...

Time to check injection pump valve!

[Roy]

Tps is used on the NA models for trany shift points, So , since the fuel pump was changed, now we are left with the only item left, injector pump. There is a small valve under the throttle shaft controlling the fuel input. if this is seized, replace/rebuild pump.

[Monk]

Ugggg, if other parts we're changed, this imo has to be it.

I hate when it's never a straight forward, (chasing the issue)

Was hoping was a fuel pump,.well,it will run like champ after.

[Skenth]

Well if it's the injector pump failing and needs replacement. ..what sort of preventative maintenance should I be doing on the new pump? Its an expensive part so I don't want it to fail again.

Should I add anything to the fuel tank to prevent the new one from failing? I never added anything to the tank since I had the truck for 2 years. How often should the fuel filter be changed. I get the engine oil changed around 4000kms. Is that ok

[Roy]

Your truck is almost 20 years old, some parts are due to be replaced.

[Skenth]

thats true...it is an old truck.


Can someone provide a link with preventative maintenance schedule and oil flushes, filters, belts etc that need to be done on the h1 to keep these old trucks on the road longer. They are unique vehicles that you don't see everyday (one of the reason why I bought mine).


Just a suggestion...can we get a section/tab on the CHC website dedicated to maintenance intervals and what to do as a minimum.

[Roy]

There is a maintenance schedule in the repair manual.   It has all estimated times when to do and a long list of stuff to check.

[Roy]

rebuilt pump $1300 ish, fuel pump relay $30ish