Herman K

Scroll down on the page of this link to see the various scenarios related to testing engine conditions with a vacuum gauge.

http://www.secondchancegarage.com/public/186.cfm

I get 21.5Hg with a steady needle reading @ idle of 680 RPM

soontobered84

That's a pretty good primer for vacuum gauge diagnoses, Herman. Thanks for sharing that.

SMTCapeCod

Ever get to the bottom of this?

Pete L

All

I can not get my 86 to run properly and am done fooling with it. I am fed up and have had it. See thread above for history. I'd like to sell it and will offer on Rennlist first. I am in Los Angeles - title is in hand.

The Car:
• 1986 928S 5-speed (early) with LSD. I am second owner and have owned since 1993
• Black / Black
• 170,000 Mile’s

Problem / Symptoms:
• Car idles OK, will not pull / absolutely no power above 3,000 RPM
• 11” if HG vacuum at LH

Recent History & Work (list is not not complete):
• New MAF rebuild by Richard at Electronic repair
• Rebuilt LH 2.2 – by Electronik Repair
• Compression test 155 to 160# all cylinders
• Radiator just rebuilt - had pinhole leak in oil cooler
• New throttle switch
• New fuel filter + fuel pressure / delivery check out
• Checked coils rotors, caps, wires and all good
• Timing belt – perfect condition, all marks align at TDC, pulled valve cover, chains tensioners OK everything seems to be lining up
• Car still running like crap, hooked up vacuum only seeing 11” Hg @ idle
• No smoke or whips from exhaust, no apparent oil burning / plugs are clean
• Smoke test - result- smoke coming out from vicinity of driver rear valve cover - replaced valve cover gasket and rear
• Car is not over heating, normal
• Still no power / very flat running

The Good

Still a good looking S3 with great interior. Carpet replaced with Grey (BUd) several years ago
Exterior is clean but hood / bumper cover needs painted
5 speed with LSD with Rodgers short shifter kit
Westminster and Koni with less then 5k miles
AC still holding 134 charge after 5 years when converted with compressor rebuilt, rebuilt HVAC head and new vacuum dampers
Lots of spare parts, WSM, tools

The Bad

Poor running - I am still open to ideas
Several 928 electrical gremlins
Hood / bumper cover

Send and email to Petes928@aol if you are interested. I have not set a price

fbarnhill

My issue turned out to be a bad coil. The DS coil, that is buried under the ps reservoir was so corroded inside where the coil wire plugs in that it could not possibly allow for a good connection. You have tried everything else and so did I. Looked for over a year only to stumble on while taking the entire intake off and replacing every sensor on the engine with new stuff.

Good luck,

Mrmerlin

Pete L

Closing out the string of posts. THe drivability issue was due to slipped timing ring on flywheel. See theses posts

https://rennlist.com/forums/928-foru...-flywheel.html