Backfiring through Zeniths
 

Okay all you clever people why does my 2.2 T backfire through its carbs?

The car also gives starts misfiring sometimes, but then clears if the engine is switched off for a while.

Please help!!

Steve,

backfiring through the carbs normally indicates lean mixture. There have been several posts dealing vith this problem, try and search for -lean mixture- on the forum.
One post with some ideas

http://www.pelicanparts.com/cgi-bin/vb/showthread.php?s=&threadid=59733

Bjorn :cool:

SteveW,

What size idle jets are on the carbs? Keep in mind they may not be as marked as a previous owner may have reamed them out. My 911 2.2 also has Zenith carbs. I had this problem when I first purchased my car and fixed it by going to 55 idle jets. Jets are not easy to find as Solex is no longer in business. I have been told VW used the same jet on some of the early cars. I used a wire spark plug guage to roughly determine jet size 22/1000 is 0.56mm 20/1000 is 0.51mm. My jets were as stamped and were 3 different sizes 47.5, 55, and 62.5 go figure.

CraigD, I've no idea what jets are in the car, but I have changed the fuel filter again. It had a lots of little black grains in it (again).

Late last year, alcohol was added to our fuel and I'm begining to think it is doing something to the obviously old fuel lines. I also ran the tank very low some weeks ago to see how long I can drive for with the red light on - I think I sucked some crap from the bottom of the tank into the filters, because it was fine on a fairly hard (nice) drive today.

I've only had the car since just before xmas and all I've done so far is change filters, oil and plugs.

Cheers