Warm up Reg. CIS Backfiring

[ssinparadise]

I have a 73 1/2 t that has two major problems that may be related. Thought Id look for ideas. I have a cold start problem. Symtom: 2 second run and die until warm when it runs pretty good. I also get sizable backfiring when the throttle is opened quickly (car is warm).

Would a faulty warm up regulator cause a lean mixture even when warm?

Ideas?

Thanks
Scott S.

[wckrause]

"Would a faulty warm up regulator cause a lean mixture even when warm? "

The warm up regulator controls your CIS control pressure, which controls mixture. So yes, a faulty warm up regulator can cause a lean mixture even when warm.

Check it with a CIS pressure tester (about $50 at jcwhitney.com).

Wayne -- Pelican should carry CIS pressure testers.

[john walker's workshop]

you ARE using the hand throttle until it warms up, eh? without it, they die repetedly, good WUR or not. the 73 WUR has been superceeded to the later design. an adapter kit comes with it, usually. the state of the tuneup counts a lot too.

[pohsche]

Your on the right path. I just had the same problem with my'77 Carrera 3.0 and with a slight adjusment with the newer type unit, my backfire and cold running problem is gone.

Alan Poh