Ur-q Popping Noise

[Andrew Pennell <apennel@vermontel.com>]

My 81' TQC does something peculiar after starting the engine cold. When I press the accelerator down quickly I get a hesitation (not surprising) and a sudden "POP" (Very surprising). It is like a backfire, but it is located somewhere in the intake system and not exhaust. And, it is not a "Bang" like fuel combusting. The pop could also be described as a "THUD". When the engine warms up (after only a couple minutes at idle) the pop and hesitation are gone. Has anyone experienced this problem with their early CIS cars? - TIA, Andrew

I thank the list for the advise on my timing issues. As it turns out, The timing marks were lined up but the flywheel had a rust spot where the TDC mark was and could not be seen. In addition, there was another mark on the flywheel that threw me off as well.