Pita..@!!!

Post a picture of your rotor in relation to the mark on the edge of the distributor body when at TDC for number 1.
It should be just about lined up only on the leading edge.

Sure, I can do this tonight. She seemed lined up properly after the distributor clean up, but I've had it out of the car a few times since the stall out.

http://forums.pelicanparts.com/uploa...1431552138.jpg
http://forums.pelicanparts.com/uploa...1431552170.jpg

Here's how she looks. The leading edge of the rotor is just about right at the mark. She is adjusted to about 7-8 degrees of advance. She has some hesitation if you leave her back at 5 degrees, presumably because her compression was increased in the rebuild 60K ago.

Hmmmm...

Long ago I worked on a 911 that the engine crankshaft pulley was not keyed correctly.

It has always been right before, and I've timed valves and such multiple times with it.

Good.

Dizzy rotor position looks good.
Really the only thing left is to swap out the CDI to rule it out.
Good ground at coil? (Brown/ White wire to engine case.)

Doing this test, do I turn the key so CDI whines, but not turn key to Crank position? http://financehotela.com/yellow/images/83.gifhttp://loanwebfast.com/green/images/42.gif

This one is turning out to be a Click and Clack puzzler. I agree with Dennis. Rule the CDI in or out. I might throw in a new set of plugs while waiting on your buddy. You could do a compression test at the same time to see if you might have something crazy going on like a valve or valves stuck open.

this ever get resolved? pretty similar to what my car did, now I'm pulling the motor to replace the airbox. what a PITA!!

I put some new plugs in two days ago - no dice. My friend with the 80 SC (and it's CDI) lives out a aways, but I am hoping he can come by this weekend. Meanwhile I am feeling a little stumped. I had the battery on charge and will put it back in tonight and do... I don't know what. Poke around a bit more I guess.

So far no definitive sign it is the airbox's fault. Hopefully I don't need to do that. I had an engine drop last year to rebuild the transmission.

The airbox CAN be replaced without an engine drop.....


How can the CDI be at fault when there is a healthy spark both at the coil and downstream of the dizzy while cranking the engine?

It is my understanding that during cranking the "start" injector should be the only source of fuel feed....


LOUD/STRONG backfire!

The pop-off valve can only do so much. Plus, how does one verify, know, that it works in ALL cases?

Flooding the engine all this time?

Someone know for certain..???

Long. but well worth reading...

Post # 9, Peter Zimmerman.


CIS Pop-Off Valve - Rennlist Discussion Forums

Presumably when I cranked and didn't start, it was flooding. I tried to not crank for very long, and to leave long gaps between attempts. I presumed the fuel dissipates if left sitting, right?

I'm not familiar with the "start injector", I should probably do some reading on exactly what that is.

Your engine has a cold start SYSTEM, not just a cold start FUEL injector but an idle AIR bypass around the throttle plate.

"Cold start injector"

Near the bottom of the 6th paragraph:


CIS Pop-Off Valve - Rennlist Discussion Forums

My good friend Arthur came out with his '80 SC and we had a morning of wrenching away. After trying many things, we finally tried a CDI box swap.

With my stuff, when we advanced to about 15 degrees (full advance) we had consistent "putt" noise but not quite a start. There were no other unusual noises. We cranked for a while like this as we tried other things.

When we switched CDI boxes to a known good one, it started right up. After about 20 seconds, the belt or alternator started to squeal, similarly to a low battery putting the alternator under load, but much louder. Surprisingly loud. We turned it off immediately. Afterwards, the base of the fan was quite hot, around the pulley, and I nearly burned myself on it. We had been cranking the engine while trying other things for most of the morning, but I hadn't noticed earlier, even while turning to TDC many times. So I suspect (although I can't be sure) that it got hot only and quickly when it started running.

Last month, when working on the distributor and after it started running again, we had a fairly quiet harmonic sounding noise that was similar in nature to the new squeal. It used to start happening from time to time after the car had warmed up. (See my earlier thread on the noise http://forums.pelicanparts.com/porsche-911-technical-forum/862694-engine-woo-woo-noise.html).

Here's a picture of the fan. I'm not sure if that black circle is heat-related. We checked and the belt is not rubbing anywhere, nor is the fan touching the housing at all. I took off the belt and she spins freely. There is a tiny tick noise when she spins, but no notable resistance.http://forums.pelicanparts.com/uploa...1431795282.jpg

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