trying that today. thanks Alan

Crap!!!!! I give up. Starts immediately, then dies. I have leaned out the mixture until it does start, then turn it clockwise to enriched it until it fires. Same thing.

Did the idle screw adjust as Alan suggested….. I am not getting anywhere.

Checked vacuum lines for leaks, even removed the intercooler to have access to all lines..nothing.

What am I missing here. Obviously the cold start injector works, then when that fuel is gone, he engine dies. Doesn’t run long enough for me to depress the gas pedal.

Sounds as though no fuel after initial start up. Not enough vacuum to pull the metering plate down? If so, a vacuum leak from somewhere.

Would a bad AAR or AAV vacuum pot be a possibility? Not sure where to go from here.

The problem to me is that there is now way to tell where a zero setting is on the mixture screw or the idle screw. At least that would get you started

Your 'mixture adjust screw' is your WUR settings - CP and WP. Are they in spec?
If so your mixture is in spec.
The idle adjust (mixture) is the small allen head one (3mm) by the airplate. To get a ground zero base - either pull an injector - or listen for the injector squeal - different to the pump whine.
Are your pumps running? If so, are your injectors squealing/spraying? They should not be with the airplate closed. If that is the case, then richen the idle mix until they do - clockwise turns. As soon as fuel moves thru the injectors - stop, and back track just til they stop. Do not linger. Don't fill engine with fuel. But now you are close to where you need to be for idle mix - until you have a warm engine and can tweek.
Was your idle speed OK previously ? That is the big knob by the TB butterfly.
Alan

This is a new rebuilt, modified engine. So I am starting from zero.

Fuel pressures are all in line. I have an adjustable WUR and both hot and cold pressures are right on.

I just purchased new 3.5mm I.D. vacuum lines and will probably replace all of the old lines. Pulling off the intercooler again tonite and quadruple checking all vacuum lines.

Alan, how do you guys usually plumb the open port off of the WUR? I see that it usually runs back to the air filter unit. I believe this is for fuel overflow if the WUR fails. Some members here I have seen that they plug that opening. What would you suggest?

Thanks all

If it is the port on top of the WUR, that is an air vent.
Yes it sort of makes sense to plumb it to the airbox - in the slight chance the metal disc may rupture. But 99% of them are left venting to atmosphere. I have not actually heard of the metal disc rupturing.
I am struggling to figure what may be the problem here other than a possible lean mixture. Have you confirmed the idle mix setting is correct?
Alan

Alan - on the idle mix setting......still working on it. Not sure either one is set correct. Its been trial and error.

So I have it firing up immediately - then dies. sometimes it might stumble a bit after. Not backfiring at all - however occasionally it will spit one out.

Driving me nuts!!

At a guess it seems too lean. You need to be confident you have that idle mix screw correct before you can eliminate that. It is a sensitive adjustment. Starting from base zero, if you are a whole turn out, the car will not run.
Alan

I have been working on my 1977 930. I pulled the gas tank and used a lye mixture and lots of sloshing / agitation over a few days with flushing out all the junk through the filler neck or the drain plug at the bottom of the tank. It would have been impossible to do this with the tank in the car. In addition getting all the solution / water out will be impossible in the car based on the baffles and crevices. My under tank drain plug had failed which took out the front pump as well. How certain are you that you’re getting clean gas from your tank post cleaning in the car?

Okay, Big thanks to pelicanite Alan for all the PM help suggestions. Alan helped me to find the "zero" setting on the mixture screw. This is what I needed. A starting point. This is a newly rebuild motor, short block rebuild, including twin plugged heads, top of cylinders machined for top gas seal ring, Gruppe B cams and interior block mods from Supertec. Top end mods, turbocharger, intercooler modified to a long neck, billet aluminum injector blocks and modified to accept water methanol injectors (6 total), etc. from Chris at TurboKraft. Adjustable WUR and fuel head rebuilds from Rarely8.

It started and idled. Idling high right now, but dialing it in. Next I need to get my Innovated Motorsport AFR gauge set up so that I can finish dialing in the mixture.

Motor sounds great! Just needs final adjustment.

Thanks to all for the help. Not my first time owning a CIS 911, but my first time diving into one.

Great that you are finally up and going.
The AFR gauge is a MUST. But you don't need it for tuning the idle mix. Every engine has different numbers it is happiest at - esp after modifications. Tuning by ear (as I described to you via PM) will be your best shot really. You can do that any time you have a warm engine. But with new cams etc I would just dial it in approx right, and get some break in miles on it first. You don't want it sitting idling for extended periods from the very beginning.
Alan