what causes pinging & backfiring, low grade gas (87 and lower) timing, exhaust system ?? all the above?? Cabanaboy OUT!!
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what causes pinging & backfiring, low grade gas (87 and lower) timing, exhaust system ?? all the above?? Cabanaboy OUT!!
Pinging...Timing too far advanced - lowgrade gas
Back firing... Fuel mixture too lean - timing - exhaust leak
Back firing... Fuel mixture too lean - timing - exhaust leak
Back firing out of the carb or exhaust? Pinging under load? Knocking? Running-on after shut down? Ethanol blend or just low octane rating?
A little more info, OK?
A little more info, OK?
Likely not the octane. More like HEAT, is it too hot this week compared to others? Maybe need to adjust the timing a tad. My car does not backfire yet at Carlisle a few years back, uppers 90's and humid it was like driving a shotgun when you let go of the gas. An exhaust leak can also create backfire.
You can look at the timing, idle adjustment to a higher idle helped. If you do not usually have a backfire problem then look to adjust for outside temp.
You can look at the timing, idle adjustment to a higher idle helped. If you do not usually have a backfire problem then look to adjust for outside temp.
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Everything mentioned above is correct; also compression ratio enters into the equation; too high a compression ratio for the octane you're using causes pinging and/or knocking which is devastating for your engine. Try to use 93 octane gas for these cars.
Desi,
What has changed? The weather, your ride, fuel, tune up, exhaust? or was it this way all along?
What has changed? The weather, your ride, fuel, tune up, exhaust? or was it this way all along?
One thing to try is high octane fuel, CAM2 if you can get it. If the pinging goes away, your timing is too advanced. Post more on this as asked by others: backfiring when and thru carbs or out exhaust. Or just verify timing at around 28-30BTDC at 3000RPM, and idle it down at 900RPM. Another question is how are your carbs adjusted. They have to be synchronized and balanced for CO.
thanks for your responce, took speedy over a local vw wrench, he adjusted the idle and this help alot ( he said it was getting to much fuel at idle, also the backfiring seemed to quite down and said the little backfiring I'm hearing now was coming out of the exhaust , dont' worry? Added Lucas Octane boost to 91 octane Chevron runs very good ( well this damage my engine? claims to eliminates pinging & dieseling and also lubricate piston travel anyone use this product??) Thanks Cabanaboy OUT!!
High idle (high RPM's)doesn't usually cause a backfire until you shut down the motor and may then cause a "run on - dieseling condition on a higher temp motor.
Backfire through the exhaust can be a leak(s) within the physical connections within exhaust system. Timing, lean burn condition i.e. jetting, loose intake gasket, improperly balanced carbs or a burnt valve that allows for incomplete/lean burn.
A booster additive in many cases only masks the problem and is a liquid Band Aid to make up for some of the mentioned problems as well as a host of other possibilities.
Rather than run the motor with the exsiting problems, they should not be there hence, there is more to look into and time for another mechanical and diagnostic inspection, hope this is of help.
Backfire through the exhaust can be a leak(s) within the physical connections within exhaust system. Timing, lean burn condition i.e. jetting, loose intake gasket, improperly balanced carbs or a burnt valve that allows for incomplete/lean burn.
A booster additive in many cases only masks the problem and is a liquid Band Aid to make up for some of the mentioned problems as well as a host of other possibilities.
Rather than run the motor with the exsiting problems, they should not be there hence, there is more to look into and time for another mechanical and diagnostic inspection, hope this is of help.
Backfiring out of the exhaust should NEVER happen in a health motor. You HAVE to get that fixed. The exhaust valves are very close to the exit port on the VW engine, if you have a leak where the header meets the head, it'll cause a backfire and a LOT more problems to the valve/seat/head port.
>Alan paraphrase< Fix ALL of the problems and be done with it, OK?
Luck,
TC
>Alan paraphrase< Fix ALL of the problems and be done with it, OK?
Luck,
TC
Speedy going up on jacks this week, i hope i can find this leak. can duel carbs that arn't in sync cause backfiring? Cabanaboy OUT!!
...........can duel carbs that arn't in sync cause backfiring?
Yes they can, you can also pull all four plugs and get a read as to how the cylinder is burning this narrows the search a bit.
Yes they can, you can also pull all four plugs and get a read as to how the cylinder is burning this narrows the search a bit.
I'm very determend to fixing this problem, thank you all for posting possible fixes, this site ROCKS, the info helps me sleep. anyway I'll keep you posted. Cabanaboy OUT!!
FIXED !!!took speedy over to Dave"s shop HANSA Motors in H.B. first thing we did is set both idle's the same next we took a reading with his snyc meter, we found #1 intake was way weak after cleaning out main jet & also checking the air jets (dirt or debri)put it back together and adjust- BINGO nice power band no drop out no backfiring I'm stoked .I hope this info helps others. L8er Cabanaboy OUT!!!!