No Power 40 MPH and Above........
Asked by secret_bubba Mar 29, 2007 at 11:46 PM about the 1999 Chevrolet Silverado 1500 LS Extended Cab 4WD
Question type: Maintenance & Repair
0 - 40 acceleration is decent.
As Soon as the truck hits 40 mph you can feel a Huge drop in power / rpms, they will settle in about 1500 and even with a 3/4 quick acceleration, the truck jumps like it wants to take off, but right away kills down to that 1500 rpms, and you can not get any acceleration until you put the truck Full Throttle. Any Ideas ?
6 Answers
It could be a choked up catalytic convertor or exhaust system.
secret_bubba answered 17 years ago
I have 3" aftermarket exhaust installed on the truck. It was installed without Mufflers, but the GM dealer told me that, that is what is causing the problem. So I put high-end muffler back on, and problem still exsists. Could it be something in the TPS, or CPS ?
sounds like a tps problem to me, except for decent acceleration until 40. i would definately have a shop put a scope on the tps tho, it takes like 4 minutes
my truck doesnt have any problems like that... its smooth all the way through, but it could be somethin to do with the engine programing... ive got a hypertec ecu and it makes the truck sooooo much better
it accelerate fine till 40 mph? and then at WOT does it accelerate like WOT or slow?
not a tps issue if it is accelerating fine until 40
