I have a 98 sierra ext cab 4x4 with a vortec, it is not a daily driver,
I mostly use it for camping on the weekends, about 2 months ago I noticed a stumble or hesitation when going down the freeway, this happened a couple of times and has gradually gotten worse to where it happens more and at slower speeds too.
a couple of times it started surging when stopped from up to 1200 rpms down to a couple of hundred and then stalled too, upon restarting it had to be cranked for a bit before it started.
So yesterday I replaced the distributor cap and roter, the plugs and plug wires, added some fuel injector cleaned, spray cleaned the throttle body, cleaned the MAF sensor the drove the truck for about 50 miles... no change at all.
I mostly use it for camping on the weekends, about 2 months ago I noticed a stumble or hesitation when going down the freeway, this happened a couple of times and has gradually gotten worse to where it happens more and at slower speeds too.
a couple of times it started surging when stopped from up to 1200 rpms down to a couple of hundred and then stalled too, upon restarting it had to be cranked for a bit before it started.
So yesterday I replaced the distributor cap and roter, the plugs and plug wires, added some fuel injector cleaned, spray cleaned the throttle body, cleaned the MAF sensor the drove the truck for about 50 miles... no change at all.