chuck barker

ok..I'll try that. Thanks!

Thanks for the reply. Last night, I had carefully read my Haynes shop manual (which tells you how to take things apart and out them together, but very little about diagnosing what might be wrong), and thought exactly the same as you describe...like maybe air was sneaking into the intake manifold thru this bypass, and "tricking" the flapper modulator valve right below the injector distributor on the big end pf the rubber plenum that extends from the air cleaner chamber over the top to the intake manifold and the pedal-controlled big butterfly valve, and I plugged both ends of that hose (its about 3/4" diameter) with a diaphragm (actually, two layers of a piece of latex hospital gloves), but it made no difference whatsoever! So, any other ideas??? THANKS!

I need help!! I have 6 911's, 67 to 91, so you'd think I could figure this out, but I'm stumped. On way back home from Portland Intl Raceway Rose Cup late this afternoon...3 days of fabulous Porsche racing, but I was not an entrant, just a fan. In my '77 911S, with K-Jetronic injection (functions flawlessly always) Accelerating on to freeway. suddenly, won't stop accelerating. Managed to get home, by standing on brakes and switching engine off with key. Examine every moving part from pedal to throttle pedal, lever, cable, side of transaxle case, pivot up to air intake butterfly...all functions perfectly. Removed air cleaner, and the big rubber plemum which takes air from air cleaner chamber over top and feeds down to intake duct. Again, butterfly works perfectly, seats properly. The big valve air regulator below the injector line distributor works fine, lifts up & gently reseats itself. Checked repeatedly this 4 times over. Even tried removing fuel pump fuse to let crank and run dry any residual fuel; it soesnt atrt at all then, but immed starts (and starts racing immediately) as soon as use re-installed. But...put it back together, try to start, it fires instantly. and you can only allow engine to be on for less than a second...it immediately starts to race as though you have your foot on the floor, but the throttle is still resting in the completely closed position!!! I had long ago removed thea air pump. So then I tried blocking off, with rubber cover, the air tube that comes up behind the big rubber plenum, thinking it was getting air in that way, but that made no difference. What is happening? How do I fix this??? Thanks everyone! Chuck Barker chuck@timberlinefinancial.com Tel: 503-847-6360 67 coupe 68 soft rear window Targa 76 911S Targa 77 911S Targa wide body conversion 84 944 91 911 Carrera