Ok, I have a 98 GMC Z71 w/ a 350 vortec....it drives fine with no problems unless you "get on it"...then the rpms rev up but it won't hardly accelerate. However if I let off a little it will pick up speed. I noticed this on the interstate do around 65-70 but it also does it in lower gears too(but only when I "get on it". Any suggestions as to what this could be? My friend's dad had his dually put in the shop today for the same thing and he was told it's something to do with his fuel pressure, is this possible? Any help is appreciated.
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Why do you never have enough time or money to do the job right the first time, but enough time and money to do it again?
Got all the certifications
25 years ASE Certified Master Technician
GM WCT
Yea..I work at a DEALERSHIP....got a problem with that?
GM had its share of problems with fuel delivery during the late '90's. The result in many cases will be that the trans downshifts, but the lean mixtures resulting from low pressures will cause the engine to lose power, and the trans will not upshift. Ray
Shifting/revving problem...need advice.
