intermittent backfire

[psg]

I have a backfire which happens only occasionally and generally after the car has been running a few minutes but sometimes when completely warm. Sometimes on acceleration and sometimes when just cruising. Any thoughts?

This is a '78 1800cc with a new Weber 32/36 DFVE and a reconditioned head with new rings and honed cylinders. Runs good starts easy idles smooth. psg

[So Cal Mark]

if it pops back through the carb it's probably too lean

[psg]

you know that is a good question but my ears tell me it is coming out the tail pipe.

[So Cal Mark]

backfires out the exhaust can be caused by an overly rich condition or ignition issues. Do you still have points in the dist? If so, check the gap

[psg]

Yes still have points and will do thanks. psg

[psg]

Are they likely to be too wide or to narrow? psg

[txspider]

Bad condensor used to do that to mine - electronic swap - no more issues

[psg]

thanks. psg