i have a 87 s10 blazer
2.8 v6

im having a issue cant get anyone to figure it out , even dealership couldnt im sick of paying people to look it over to end up still having same issue

thought this site can help

whats happening is randomly when im driving
ill go to stop at a light or stop sign and the blazer starts rev up
i see the rps going up then down up then down like im giving it gas then letting go then giving gas again then letting go

it will do this till i start driving again then stops

almost has cause me to rear end someone.

iv replaced tps sensor
vac lines have been replaced
most of the engine has been replaced lol

no one can seem to figure out why its doing this any ideas anyone ???

 

did you check you MAF sensor? do you have any codes? you can have a intake leak cuz when your MAF is going bad or if you have a intake leak that does what your saying. did you do a tune up a 100% tuneup?