I have a 1991 sonoma/s-10 (v-6) and its hard to keep running after its started,rough idle. When driving the motor will sometimes backfire and cut out. After about 1 mile or so of driving the problem goes away. When the motor is again started ,hot or cold the rough idle problem comes back and sometimes wont stay running at all until its ran for a few minutes. I tried all the tune-up stuff and still have the problem. Any help would be much appreciated.

SOURCE: rough idle on 1992 sonoma truck

i have a 92 sonoma as well and its suppose to be normal its due to an unbalanced camshaft

SOURCE: 1991 Olds Bravada 4.3 v6 rough idle and backfiring.

Ok guys, let's fix these things here!
Just went through this myself, so do the following:
Go to your local parts store and buy a Haynes Repair Manual.
You need to read the book first, learn how the ECM (Electronic Control Module) works. You'll see that there are alot of sensors and components that make up the fuel emissions bologna.
The nice thing about this system is not only does the ECM control all electrical functions, it also trouble-shoots it's self. When a component or sensor goes out, the ECM stores a code for that event in it's memory. You can use the Haynes Repair Manual to put the ECM into diagnostic mode and thus read any codes present.
So, all that's left is replacing what the EMC tells you too! :) Good Luck!

SOURCE: '99 chevy Silverado Z71,5.3 engine.....will not rev when hot.....

try replacing your EGR Valve, or your Oxygen Sensor

Jerry Koski

• 443 Answers
• Posted on Apr 12, 2009

SOURCE: rough idle, backfire on acceleration

check everything you can under the hood your air intake system all of it especially make sure all clamps are tight .. and make sure all vacuum hoses are good and not cracking or broken or just loose . you might run a little fuel cleaner through a tank of gas too cleaning the engine fuel system up some. just a few ideas.. Jerry

SOURCE: 1991 VW Cabriolet runs rough during idle

Check the hose between the inletmanifold and the pipe to the brakeservo it normally gets old and a crack in so the engine sucks false air on cylinder 4, causing engine to run rough or uneven.