Any 911 gurus out there?

So I've been trying to get my car to run better. The engine is a 911 2.4S spec, Webers, headers, sport muffler, Electromotive HPV-1 crank fire ignition, Fidanza lightened flywheel. The HPV is set at 10 degrees INIT, 18 at 3000 and 6 at 6000. Webers have 32 venturis, 135 mains, 180 air correction and 60 idle jets. Both air and idle adjusting screws are out about 1 1/2 turns. Float levels have been set, injection pumps set at .05, and carbs balanced for air flow side to side and each throat.

The car is amazing at idle...after it warms up a bit it settles right in at 900 rpm and just burbles as it should. My old engine always hunted around for an idle speed. Shut it off and you can start it again standing outside of the car no problem...no tickling the throttle or anything like that req'd. Tromp on the loud peddle and responds quickly, reving right up to the 7,000 rpm limiter. However, rev it up slowly from idle to about 2,000 rpm or drive around town anywhere in the idle to 2,000 rpm range and it coughs and sputters both out of the carbs and through the exhaust, through the exhaust moreso than the carbs but both nonetheless.

Thoughts? I really just wanted to get it running so I can load it onto the moving truck but now that its this close, I wouldn't mind driving it around a bit.

FWIW - I'm no expert by any stretch of the imagination, but I had a similar experience with my 68 911S blueprinted/balanced to 2.2 RS specs (with triple-throat webers). Long story short, worn bushings for the throttle butterfly shaft (not sure of the name for these). Replaced those and perfect idle to high rpm.

Where's Angela. I'm sure she'll know.
Doug

ANGELA OH ANGELA
U R NEEDED AND PLEASE HURRY BEFORE VINCE OFFERS ADVICE

It does sound like an air leak in the intake system but I've checked all the obvious and can't locate one. Turning the idle adjusting screws out more, now to 2 3/4 turns has helped significantly but still some popping, snorting and farting from 1,000 to about 2,000 rpms.

Definately not a carburetor magician by any means, but we discovered the hard way that nearly EVERY 911 linkage out there is out of adjustment or needs to be bent to open both sides evenly.

On the spyder, we had two different so called "experts" attempt to adjust the carburetors. They both had the carbs balanced at idle, and it ran great WOT, but part throttle was kind of crappy. We got pretty frustrated and decided that the $90 per hour wasn't really well spent. So we followed this to the letter:

http://www.pmocarb.com/installation.htm

Our linkage was signficantly off. Because there is a cam effect involved with a 911 linkage depending on how you adjust the rods and how the linkage itself is bent, you can get nearly infinite possibilities of wrong but only one of right. What was happening is that both carbs would open the same amount at WOT, but at partial throttle, one side opened before the other. It just ran ratty.

We fixed that, roughed in the mixture and it ran better than ever. I took the car to a REALLY awesome Porsche Mechanic in San Luis Obispo (Guy's Porsche) for precise adjusting and that guy was master. We made the engine run well, he made it sing.

Don't know if this will help you or not. You should be able to set the Webers up using the same procedure as the PMO's. Some interesting notes in those directions regarding throttle shaft binding as well.

Also, on old webers, you REALLY need to watch the throttle shafts. We've had several sets with slop in the shafts. There is a way to fix it, but it will drive you mad trying to sort it out before you figure out what's wrong.

Hope it helps.
angela

Thanks Angela for the link. Its very similar to others I've seen such as...
http://youroil.net/weber_tuning.html and...
http://performanceoriented.com/technical.htm#PerformanceTuning

It seems that turning out the idle screws helps. I'm sure the Supertrapp I have on it contributes to the problem as its little more that a straight pipe with perfed baffles. I tried the sport muffler but there's some fitment problems that I just don't have time to deal with.

I'll just keep fiddling with it. The idle is nice...no more having to heel/toe at a stop to keep the engine going. I also replaced the 1st gear synchro on the 901 box...should have done this at the get go. Now I don't have to come to a complete stop before I downshift into 1st.

Oil temps seem high. Using a laser temp reader on the metal oil filer I get readings of about 220-230F. The engine compartment is poorly sealed so I guess I have to deal with that. Perhaps header wrap would cut down on the heat transfer? I have lots of that sitting around.