Quote: pop from carb means there is ignition with the intake valve open. that would most commonly be ignition [ malfunction] at the wrong time, or, ignition is at the correct time but the intake valve is open at the wrong time. bad valve spring,bent or broken parts keeping valve open.....either way it is a timing issue
could be, but again...not always! I've experienced it twice, and neither time was it timing related. it was a bad/weak coil the first time, and a lean condition from a vacuum leak the second time. cam, timing chain, distributor timing were all fine.
any time you get combustion in the intake and out the carb, you have a timing issue.[meaning a bad coil firing at the wrong time will do it].yes it is a bad coil but it is firing at the wrong time. a backfire through the carb can not happen unless the intake valve is open.i only say this to help the thinking process of what [when] it is actually happining.
