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Discussion Starter #1
My 83 Spider keeps on running when I turn the ignition key off. Car was running fine since I bought it about a year ago but the other day while driving home the engine did no longer respond to the accelerator pedal, did not get up to full speed and once stalled it was difficult to get it started again. Well after a Saturday afternoon of trouble shooting I determined that the original problem was the in-tank fuel pump and that a Saturday afternoon of trying to find the problem took out the main fuel pump as well. I replaced both fuel pumps and the engine starts up and runs fine – but it does no longer shut down either just keeps on running even if I turn the ignition key into the off position. Pulling the wire from the #86 terminal on the main relay shuts down the engine immediately! And as soon as the engine stops there is no voltage on the terminal telling me that the ignition switch must be OK. Well this wire also goes to the #15 terminal of the drive relay. Maybe this drive relay keeps the main relay energized. I pulled the drive relay from its socket while the engine is running – engine stops. Without the drive relay installed I can start the engine fine and the engine stops OK once I turn the ignition key off. Well that’s cool, who needs this drive relay? What does it do anyway? Well reading this forum I learned that the drive relay actually provides power to the fuel pump after the engine is running (very poorly documented in the work shop manual by the way) and by further troubleshooting I learned that the previous owner had the #87 terminal wire from the drive relay (to power fuel both pumps) directly spliced into the wire going to terminal #15 (power from ignition) in effect powering both fuel pumps all the time as long as the ignition key is on.
OK, that’s the way I drove the car, both fuel pumps “hot” wired but the drive relay still installed. Engine did shut off fine before all this transpired. Now it only shuts off fine if the drive relay is removed. How can the plugged in drive relay be responsible for me not be able to shut down the engine?
 

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1966-2013
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13,741 Posts
Because when it gets old/worn, it has the tendancy to sort of spot weld it's internal connections shut due to the arcing involved in that type of relay.

For giggles, start it up with the relay in there and if it doesn't shut down with the key, give the relay a sharp rap about midway up the casing with a screwdriver handle or the like.

If that kills the engine with the key off and allows otherwise normal operation, then it's time for a replacement relay.
 

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Discussion Starter #3
I tried your suggestion but the engine kept on running. Than I removed the cover from the relay and tried it again and no again the engine kept on running. I was OK with removing the cover since I did order a new relay but I'm still wrestling with the question why. The "hot wired" fuel pumps and no relay seems to work just fine. But on the other hand I do want to bring it back to the original set-up. By the way the Altitude Compansation Device is gone too.
 

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1966-2013
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13,741 Posts
With the cover off, did you see the arcing bit? Did it move somewhat freely and seem clean/free of scoring/burning with the key and engine off?

Sounds like someone got really 'creative' with your wiring at some point. Mayhaps contacting papajam and seeing if he's got a wiring diagram for your year would be in order to help get things straightened out. (his far and away exceeds the quality and clarity of any of the book or disc stuff out there)
 
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