rough start

[fireguyfire]

Hey guys; a question regarding my 76 911 targa.
When I start the car cold it initially starts fine, and then after 15 or 20 seconds it gets kind of rough and "poppy"; I have to bump the accelerator pedal a few times and after 20 or 30 seconds of this it revs beautifully and is a fantastic driving car; until the next time you start it dead cold.
If the car is warm it starts like a dream and does not do this.
Anyone got an suggestions as to what I have going on and how to tweak it?

[Bob Kontak]

"Poppy" through the exhaust or the throat? Throat means lean. Exhaust means rich. Suspect lean for cold start control pressure then it gets to "correct" warm control pressure and all is good.

My gut feel is wait until it gets cold (bed time for driving) and then send your warm up regulator to Tony, boyt911SC. He is in Philadelphia.

He will fix it where required, tweak it to factory specs and guarantees his repairs. I don't know the cost but a simple tune up should not be too much more than a set of good pressure gauges.

A set of pressure gauges will tell you if you are out of spec. Then what do you do? You bump the plug and maybe you will hit the magic spot, then repeat if not so assuming all else is well. And how do you tell that without robust study?

Take it from a ham handed enthusiast, outsource this job to a certified WUR nut.

Then the WUR variable will be put to bed. They work for a long time when new or after dialed in.

I believe he will send you a good loaner as well fo' free, to validate the problem.

[fireguyfire]

Tony rebuilt my WUR last year, and yes he is the WUR guru!
It sounds poppy through the exhaust.


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[T77911S]

i might write that off as a quick of CIS and an old car.
it starts great and runs great. you can spend a lot of time and $$ chasing something like that down.

make sure the ign sys is in good working condition.
use copper plugs, nothing fancy or expensive.

could just be a slight mixture adjustment. (assuming CPs are good since the WUR has been rebuilt).

again, you start screwing with things you need to either be able to get it back to where it was or live with ongoing tinkering.