Good morning. I posted the paragraphs below yesterday and someone mentioned that since I had a plug wire wore through to the actual inside wire that maybe I shorted something. Would anyone here have ideas other than bent push rod or collapsed lifter? Thanks in advance.

Evening everyone. I have a 1989 Iroc with the L98 350 in it. The motor was professionally rebuilt to stock about 2 years ago right before I bought it. The car has always fired immediately and ran perfect. Last weekend I changed the oil and the following morning picked up what sounded like a valve tap. Two days later I went to turn a corner and it started backfiring out the exhaust and back through the intake. I was able to nurse it home at about 40 with a consistant backfire/popping. The car still fires and idles well (other than the tap), but the second you start to give it any gas, it begins backfiring. The more gas the worse the backfire. Im no mechanic, but can usually fix it if I can figure out what it is. Thats where Im looking for help. Can anyone put in your thoughts and ways that I can check it. With no garage and no money right this second, wouldnt you know that is when it would happen!

Update: This story was posted earlier on another site. I since found where the steering column was rubbing on a spark plug wire and had wore it literally in half. I run down to AutoZone with a big smile expecting a cheap fix. I unplug the wire and it actually runs well considering. I get the new wire and plug it in. Right back to the same thing. Its a tick with the wire off and a backfire through the intake with it plugged in. Much worse issue plugged in than without. Any help would be greatly appreciated.

Thanks in advance
Bob

 

Check your plugs and your firing order. That's all I can imagine would cause it to miss worse with the the plug wire connected than with it off, that or you have an issue with the valve train (stuck valve, broke valve spring, misadjusted rocker).

 

I had a problem with backfiring ,popping and banging. The problem was caused by the distributor...the reluctor and magnet were misaligned, causing the spark to jump to the next post as the computer was adjusting the timing. Pull the dist cap and look for damage inside around the reluctor and magnet...make sure they are tight.
I cut a hole{wide slot 1" or more} in my cap to see the rotor as it sweeps past the #1 post with the engine running. Shine your timing light at the hole...the rotor should be lined up with the #1 post. An adjustable Dial Back light should be set to 0deg. If it's not aligned...there's a problem inside the distributor