truck
9 Answers
Its notl typical a hard job but if you don't know much about cars then it would make sense to take it to a mechanic for repair a 78 chain should be a few hundred to repair, you can purchase the part on line..
Backfiring could be a bad timing chain or it could also be caused by the spark plug wires being on the wrong terminals on the distributor cap or at the spark plugs. The distributor could also be out of time. A compression test would help you determine if the timing chain was actually the problem.
Could be a valve and a compression test would show if it were a valve or if the timing chain has slipped or broken. If it were a valve, it would most likely be an exhaust valve causing popping in the exhaust. If timing chain is broken pulling the distributor cap to see if the rotor is turning (while cranking the engine) would be the best way to determine if that was the problem.
Then there is the carburetor...And the fuel pump. A bad fuel pump could cause back-firing. I would check the fuel pressure, it should be 5.5 to 6.5 lbs. Timing chains on Chevy's don't ordinarily go bad. Just checking and setting ignition timing is all thats needed.
and the carb.... When the carb has full fuel bowls during start up it should run okay until it runs low on gas and that will also cause popping and backfiring. Of course it could be dirty or worn out too. If I had that truck here at the house I could probably tell you in 15 or 20 minutes what was likely wrong with it, but sitting behind this screen makes it a tough call.
Well then Bob, get out and venture a bit...
LOL, heck it's probably a long ways from Kansas. Everything is.
