Hello
I'm still suffering with my car backfiring through the carbs and was wondering if anyone could help me pinpoint the issue... The engine has been rebuilt and this issue has been there from the beginning. It doesn't happen all the time, but generally when the engine is cold or under aceleration. All the ignition system is new or rebuilt. I have checked the valve clearance, ignition timing, dwell and all are ok. I have checked the compression and have low compression on one cylinder (110 psi vs 130 on the rest). I have checked for manifold leaks and retuned the carbs. Last weekend I pulled the spark plugs which were black, which I found slightly odd as backfiring through the carbs seems to be a symptom of a lean mixture....
So the question is, what to do next? I am thinking about getting another coil to see if it is a issue with the strength of the spark - could the coil be faulty? Or change out the distributor cap and rotor arm. Other option is to pull the head and find out what is causing the low compression, but this will cost $$$.
Any ideas on what I should do next? I've spent months trying to solve this issue but seem to be getting nowhere....
Thanks
Myles
I'm still suffering with my car backfiring through the carbs and was wondering if anyone could help me pinpoint the issue... The engine has been rebuilt and this issue has been there from the beginning. It doesn't happen all the time, but generally when the engine is cold or under aceleration. All the ignition system is new or rebuilt. I have checked the valve clearance, ignition timing, dwell and all are ok. I have checked the compression and have low compression on one cylinder (110 psi vs 130 on the rest). I have checked for manifold leaks and retuned the carbs. Last weekend I pulled the spark plugs which were black, which I found slightly odd as backfiring through the carbs seems to be a symptom of a lean mixture....
So the question is, what to do next? I am thinking about getting another coil to see if it is a issue with the strength of the spark - could the coil be faulty? Or change out the distributor cap and rotor arm. Other option is to pull the head and find out what is causing the low compression, but this will cost $$$.
Any ideas on what I should do next? I've spent months trying to solve this issue but seem to be getting nowhere....
Thanks
Myles