924Board.org

[jcontova]

Hello,
I have been going through my 1981 924 turbo and fixing minor things. I discovered that the fuel pump relay will latch on for about 2 seconds if you jog the mirror adjustment switch while the engine is off. The behavior is very consistent but obviously highly unusual. I have seen other discussions of this on the forums but have not seen any consensus on whether or not this is an intended feature, unintentional design flaw, or an indication that there is some electrical issue. So I would like to see if anyone here knows the answer?

Side question: is the fuel pump supposed to turn on when the key is moved to the first position with the engine off (pump prime)? It does not on my car. It seems like the car would start much faster cold if the pump did prime on the first ignition position.

Thanks.
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1981 924 Turbo

[924RACR]

Jury may be a bit out on if it ought to prime like that with everything in proper working order... but yeah, doing it with the mirror adjustment has been mentioned by some in the past and general thought was that it's a good indicator that you should clean your under-dash grounds (behind the fusebox, above the driver's left foot (assuming LHD car)...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Rasta Monsta]

OMG my 931 did this
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[Raize]

Mine used to prime if I turned the headlights on.

It's quite a useful "feature" in hot-start problem. It would have been smart in the first place if the FPR simply had a timer in it that bypasses the check for ignition pulses for the first 5 seconds.