Workhorse98
Newbie
I have a 1998 GMC Sierra K2500 pickup, I have replaced the engine and transmission about a 3 years ago. I have a problem with passing acceleration when the engine is operating at normal temperature rage and when climbing upgrade roadway. I will be driving and noticed the RMP will go up to 35k, then slip and go back down to 25K and continue to do this if I dont release the gas. It is sluggish when going up a hill. It usually get worse when driving on long trips or hauling my RV Trailer. Looked it everything, stuck. tested the fuel pump, i have spyder injectors, and replaced the distributor when the engine was rebuilt. need help, ran out of options. mechanics are stuck too.