HELP! 308GTSi backfire

Was it an isolated event and then it stopped, or is it happening frequenly or regularly?

 

Have you checked the spark plug extenders for pinholes?

One or more may be arcing.

 

I have the same problem when I shut the car off. Two components that may be making this happen:

1) I need to adjust my idle down, currently at 1800 after putting my car back together

2) I cut the resonator off the muffler and ran a 2.5" straight pipe to the tip.

Any suggestions?

 

Backfire is often an indication that your idle mixture is too lean and needs to be richened out a bit. That's all it took to fix a similar condition on my 308QV.

 

Possibly, did the problem start before or after you pulled the wires?

Let's keep things easy, and merge this thread into the new thread you started.

 

This happened to mine a while back, Any Ideas? Thanks

 

If you pulled the spark plug wire and extender out, chances are you didn't get the extender back on properly. It's easy to "miss" the post on top of the spark plug. You think you've got it, but you don't. The post is threaded, and you need to feel the clicking as the clip slides onto the post. Also, if you didn't get the wire clip well seated on the extender, that's another problem. In either case, you could have no spark or intermittent spark which could cause rough idling and/or backfiring.

I had a backfiring problem with the 308 a while back that was the result of a timing problem. If the engine is idling roughly, is missing, and doesn't seem to have much power, it's worth checking the timing. If the distributor is not advancing properly, or timing is way off, it could cause a problem.

On the other hand, old rule of shade tree mechanics -- if some new problem has developed since you worked on the car, look at the last thing you did, that's probably the source of the problem.

 

My '82 308-GTSi was back firing. The fault was a cracked and damaged distributor rotor.