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

5

Asked by 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

5

Got you all stumped too, apparently... Bummer...

25,445

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 39 nationwide 928 listings and the tools to find you a great deal.

ZIP:

Porsche 928 Experts

  • #1
    Tom Demyan
    Reputation
    130
  • #2
    MTA1968
    Reputation
    120
  • #3
    Michael Griffin
    Reputation
    100
View All

Related Models For Sale

Used Porsche 911
103 Great Deals out of 4,820 listings starting at $10,894
Used Porsche 944
103 listings starting at $14,900
Used Porsche 924
9 listings
Used Chevrolet Corvette
235 Great Deals out of 22,106 listings starting at $2,500
Used Porsche 959
2 listings
Used Ford Mustang
744 Great Deals out of 42,276 listings starting at $1,300
Used Dodge Charger
427 Great Deals out of 27,562 listings starting at $1,650
Used Mercedes-Benz SL-Class
49 Great Deals out of 2,718 listings starting at $3,950

Used Cars For Sale

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.