Engine Stumbles And Hesitates Slightly After Highway Driving

drumset5994 · October 9, 2008

This is the first time this happened to me, so i'm a little confused.

Today i went to see a friend of mine, i see her once a week...round trip in one day, i can easily put 100 miles on my truck seeing her. Well today i drove 55mph straight (for about 45 minutes non stop) then got on the 390, drove 65mph for another 10 minutes. Drove around Rochester. Dropped her off again at her house. I shut the truck off, got out to take a piss in the woods.

I got in 2 minutes later, turned it over. It fired right up, by was running almost like it was running shitty...the idle was erratic, stumbling. When it smoothed out after a few seconds, it was like there was a piston with a little more weight in it, and the whole engine rocked slighty, enough to shake my pack of cigarettes out of the cup holder.

When i gave it a little gas, it all went right away...and then idled smooth again.

Anyone have any ideas? I thought maybe a sticky EGR Valve after all that highway driving, but i thought that'd clean it out. I did manually clean it out a couple years ago.

alwcurlz · October 9, 2008

This is the first time this happened to me, so i'm a little confused.

Today i went to see a friend of mine, i see her once a week...round trip in one day, i can easily put 100 miles on my truck seeing her. Well today i drove 55mph straight (for about 45 minutes non stop) then got on the 390, drove 65mph for another 10 minutes. Drove around Rochester. Dropped her off again at her house. I shut the truck off, got out to take a piss in the woods.

I got in 2 minutes later, turned it over. It fired right up, by was running almost like it was running shitty...the idle was erratic, stumbling. When it smoothed out after a few seconds, it was like there was a piston with a little more weight in it, and the whole engine rocked slighty, enough to shake my pack of cigarettes out of the cup holder.

When i gave it a little gas, it all went right away...and then idled smooth again.

Anyone have any ideas? I thought maybe a sticky EGR Valve after all that highway driving, but i thought that'd clean it out. I did manually clean it out a couple years ago.

What vehicle is doing this?

drumset5994 · October 10, 2008

99 Chevy Silverado

4.3L V6, Automatic

3.08 Rear

alwcurlz · October 11, 2008

99 Chevy Silverado
4.3L V6, Automatic

3.08 Rear

How many miles on the engine?

It could be the computer is getting a false readback from sensors like the knock sensor, crank sensor, map sensor, etc. Since you mentioned something about it feeling like a dead cylinder, you might have something there. Could be a faulty fuel injector. The smaller the engine, V6, 5, 4 cyl show more response to that kind of problem with misfiring. I could say it may be a sticky injector, partially clogged, or just defective. I would try putting some sea-foam additive in the fuel tank. Certainly doesn't hurt anything and does help a lot.