1972 911 Targa Popping after Engine Rebuild
 

Good Morning All,

I’ve recently had my 1972 2.4 MFI 911T Targa rebuilt as well as it converted from a Sportomatic to a 5 speed. The problem my mechanic is having is it is popping at idle as well as when it’s running. Do you have any ideas on what may be the problem? He thinks it may be the MFI unit. The car was running well before I took it in for repair, the only issue was the shifting.

Any suggestions would be appreciated!

Thanks,

Intake popping suggests an overly lean mixture. Exhaust leaks, particularly at the joint between the header and the head, can cause exhaust popping.

Superman,
Thank you so much for your response! I will share this information with my tech. Do you think it could be a MFI issue?

Thanks again,

Is it popping through the intake or back firing through the exhaust?
Pelican Technical Article: Mechanical Fuel Injection Information MFI
http://forums.pelicanparts.com/porsche-911-technical-forum/473179-new-mfi-information-index.html

Tobluforu,

Thank you for the wonderful resource you identified. I did send this link to my tech. The one I was interested in was the linkage article. This seemed to match my car’s symptoms. I’m sure it will be helpful. The popping seems to come from the intake, but I could be wrong.
Thanks again for your advice!