86.5 928 stalls at 2000 rpm one time after starting. Idle, while smooth, slowly increases from 650 to around 1100

5

Asked by bayrrej Mar 31, 2016 at 10:20 PM about the 1986 Porsche 928 S Hatchback

Question type: Maintenance & Repair

my 86.5 has an S4 intake installed by the PO that I recently refurbished (see
pic). Also upgraded injectors to Bosch Gen III 4 hole. Also purchased and
installed a refurbished MAF (JD Porsche).  Smoke tested it and seemed fine.
Runs spectacularly except for the initial stall at 2000 rpm and the slow
inexorable increase in idle speed. Idle is also very smooth -- just fast...
Thoughts?

3 Answers

46,145

Well in the pic it looks like a vacume hose is hanging over the valve cover. But my first thoughts would be IAC idle air control. Had similar symtoms with a first gen miata. Im not familiar with 928 as much as i would like to be, so maybe check the 928 forums and see if someone else has had the same issues. Good luck.

5

Thanks for the response. The intake refurb was still in process when the pic was taken so stuff is still disconnected. My leaning is also toward the IAC but on a 928 it's under the intake - -NOT a trivial task!

Your Answer:

928

Looking for a Used 928 in your area?

CarGurus has 2 nationwide 928 listings and the tools to find you a great deal.

Postal Code:

CarGurus Experts

  • #1
    Michael Griffin
    Reputation
    140
  • #2
    MTA1968
    Reputation
    120
  • #2
    Digby Paape
    Reputation
    120
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Porsche 944
7 listings starting at $34,500
Used Porsche 911
12 Great Deals out of 214 listings starting at $22,980
Used Chevrolet Corvette
19 Great Deals out of 690 listings starting at $10,989
Used Mercedes-Benz SL-Class
5 Great Deals out of 111 listings starting at $13,888

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.