Surges

CRAIGBARNEY

MEMBER
1993 CHEVROLET S-10

4.3, with a W vin code, I got it from my brother in-law, he got rid of it because they had the same problem and his mechanic had changed the computer, distributor, spider fuel rail, map sensor, knock sensor. The S10 when you first start it idles fine, but the check engine light comes on, indicating electronic spark control failed. After a couple of minutes you can clear the light. But when you drive it on the road it starts to loose power and wont pull itself. You give it more throttle and it will do a small backfire through the intake, and surge and shake. Then you can turn ignition off, start it back up and it will run for a minute. Then it does it all over again.
Any help would be greatly appreciated. Thanks for your help.

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

There are a couple things that can cause this, but we need to start with checking for unmetered air entering the engine.

This means we need to find out if there is a vacuum leak. Here is a guide that will help with this:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

The fact that this has a backfire included when you accelerate means it could also be a timing issue. However, we have some more guides that we need to run through and see what is turned up.

Basically, we need to check these things out and that will tell us what direction to go:

https://www.2carpros.com/articles/engine-surges

https://www.2carpros.com/articles/engine-backfires-while-running

Please run through this info and let us know what you find, and we can go from there. Thanks