Sluggish DS4

[gbeyer]

Has anyone else had problems with their truck loosing serious power after replacing their pump on the electronic trucks. I have a 1995 c2500 HD, an dit just turned into a terd when I replaced the pump. I have since added JK's chip, guages, and 3.5" exhaust, with no change in performance. Help
TIA :mad:

[patrick m.]

two things come to mind, pump timming, and PMD resistor/calibrator, other than those, the pump may not be up to spec.

[Barry Nave]

Pump timing, TDC off set learn.
Can you tell us more on the R&R pump change

[gbeyer]

I had my pump fail one evening on the way home. Bought a rebuilt pump, and had recently purchased a set of new injectors from chevrolet. Pulled old pump, it was a newer number than the rebuilt pump, but they said they were interchangeable. i now have a 5288 new injectors, and have been running this pump for about 30k miles. I had it timed the day after it was installed, timing made no difference in performance. My shift points are still higher than they used to be and the truck is a real dog. Mileage is poor, about 16.5 mpg with 3.73's. I thought it was a timing issue as well. After talking with JK he convinced me that timing and resistor calibration make almost no difference. It tends to over heat when pulling in 3rd gear so I always tow in OD. I can olny get EGT's over 1100* when turning high rpm's for a good lenght of time under load. In the back of my mind I still thinking timing is off, but I don't trust anyone with it, and don't want to blow another $100 and make no difference. It made absolutely no difference when I installed JK's chip. :(