P
Pete
Guest
Whats with my truck? The truck is a 78 scottsdale, but had to get a reman engine in 2000; but It's got a 350 long block, I had both heads redone. I had one shaved but not the other, the compression on one side is around 180, on the other side it varies its like 150 I believe to be the highest, and 120 to be the lowest. I put new head gaskets on both of them. I even put a brand new edelbrock carb on, new fuel filter, plus new fuel pump and new pcv valve. It runs, but it backfires, while idling mainly, and can just hear it through the cab, your foot will vibrate everytime it does it. Right now Im running with open headers, but thats not the reason of it backfiring. Could it be possible that my valves are making it backfire, I mean I believe thats the only thing I could figure making it backfire or either a crossed plug wire, but I drew it in my handbook, where all the wires went to before I redid the top end of the motor. I keep all my parts together, like the pushrods, rockers all that, as I redid the engine. And I put them all back into the correct part and I am certain of this. And yes, my timing is correct, so thats not the problem. But I do know that when I did my valves, I did it like the handbook said, I followed the directions carefully. And after I started it up, I redid the valves around 3 times. Still no luck, perhaps I didn't do them exactly right I dunno. Is it just possible to adjust with a feeler gauge on the compression stroke and get them precise, if so how much? And before I redid all of this,rebuilding part. It was not backfiring, but what it was doing is, is was blowing out black smoke, because I had a holley carb on it, and everytime I went to adjust it it would not lean out, on both screws. It was always the same black smoke. So I opted to a edelbrock, and the black smoke left, dunno the reason, but this carb is a lot easier to tune than a holley. And the reason I re did both of the heads, is because the guy I bought it from said it had a bad valve and needed repair, and so I did. And indeed it was 1 bad valve gone. Fixed it now though. But what do yall think the reason it's backfiring? And to clear everything up, it's not backfiring through the carb, it's backfiring through the exhaust (headers). Please help. Serious answers only please.