924Board.org

BauerR · Joined: 13 Apr 2022 Posts: 10 Location: Baltimore, MD

Hello all,

Still new to the 931 platform and a lot to learn.

I purchased my 1981 in a non-running state and since got it running perfectly...until now.

Symptoms:
DME Relay "clicks" like crazy and idle goes high (1500rpm)
After a few moments the DME would stop "clicking" and everything would settle back to normal.
At first, this would happen occasionally but now its all the time and my idle shoots right up to 2000.
After the car is warm...if I turn the car off and then back on, the idle will be perfect for about a second and then back to ~2000 it goes.

What I've done thus far:
Replaced DME with another I have...no change
Replaced intake temp sensor(I have 3)...no change
Smoke test...no issues.

Any thoughts where to check next?

Much appreciated
_________________
996 Turbo ('04)
911 Turbo 930 ('84)
928 S4 auto ('89)
928 S4 manual ('87)
957 Cayenne Turbo ('09)
931 Turbo S2 ('81)
951 Turbo ('87)

BauerR · Joined: 13 Apr 2022 Posts: 10 Location: Baltimore, MD

"Checking the throttle switch"

I connected a test lamp between the battery and the "white/blue" wire per the manual.
"The lamp should light" which it did. However, the lamp did not go out when I moved the throttle.
Not sure if this is causing my problem but I imagine it is causing a problem.

Thoughts?
_________________
996 Turbo ('04)
911 Turbo 930 ('84)
928 S4 auto ('89)
928 S4 manual ('87)
957 Cayenne Turbo ('09)
931 Turbo S2 ('81)
951 Turbo ('87)

BauerR · Joined: 13 Apr 2022 Posts: 10 Location: Baltimore, MD

Closing the loop on this just in case someone else has a similar problem.

It was the throttle position sensor or "throttle switch"
Car idles great again
_________________
996 Turbo ('04)
911 Turbo 930 ('84)
928 S4 auto ('89)
928 S4 manual ('87)
957 Cayenne Turbo ('09)
931 Turbo S2 ('81)
951 Turbo ('87)

Mike9311 · Joined: 14 Dec 2004 Posts: 1678 Location: Chicago-ish

Really appreciate you continuing to post your progress even with no responses. Thank you and glad you fixed the issue!
_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car