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Discussion Starter #1
Another issue while trying to start this 3.0 gtv6 is the fuel pump runs even with the ignition off. Disconnect Battery or tap the fuel pump cutoff on the fenderwell to stop it. I cant find any evidence of creative wiring, replaced combi relay with a new one. Car hasn’t had a motor since 1994 and is fighting being woke up. not sure where to check next
 

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Discussion Starter #3
It does have a bmw afm but I didn’t think that would make it run with ignition off. I will try disconnecting the afm to see if that makes a difference. Worth a try anyway.
 

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Sounds like either the combo relay or wiring to it. The first of the two relays pulls in when the ignition is turned on. It powers the fuel injectors and the micro switch in the AFM. The second relay powers the fuel pump and it needs both the first relay to be pulled in and the AFM switch made. The second relay also gets power when the ign switch is in the Start position. It is unusual but relays can fail with the contacts welded together and that would cause your symptoms.
 

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Discussion Starter #5
My thought but I replaced the combi relay with a new one same result. I’ve not seen any modified or damaged wiring. i’m not getting an injector pulse either, related?
 

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Can you disconnect the relay and hear/feel if it is pulled in? If it is then you need to trace the circuit to the coil of the second relay. If it does not pull in and the pump runs then the power to the pump is coming from another source.
 

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Discussion Starter #7
Your description of the combi relay operation helps a lot, going to see what pins go where and make sure they are supplying power , or not when they are supposed to. Hopefully not as lost now :)
 

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Discussion Starter #8
After poring over the combi relay diagnostics page on The Bus Depot’s web site I did a lot of testing with the multimeter. Everything seemed ok till I put it back together. At first no pump then when I moved the afm flap pump came on and would not stop even after the ignition was shut off. On a lark, something I should have done step 1, I disconnected the afm. Pump stopped. This is all with the ignition off. Evidently doesn’t like the bmw afm. Gotta search through my stash for a gtv6 afm, if not, Jim has a few spares. Testing pin 36 on afm is on off as it should be
image.jpg
 

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Could it be that the AFM is sticking and keeping the microswitch closed? I had an AFM that became sticky after a backfire.
 

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Discussion Starter #10
Testing the switch with a multimeter seems to test ok, on-off as the flap is moved. Just gonna try another one and keep my fingers crossed.
 

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Discussion Starter #12
Will try the afm from my gtv6 tomorrow and see what happens
 

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Discussion Starter #13
Still no luck. Tried SEVEN air flow meters, and installed the combination relays in my gtv6, which worked fine. When ignition is turned on, triggering fuel pump by moving afm flap starts fuel pump and it keeps running even when ignition is turned off. Stops when afm is unplugged. Running out of ideas.
 

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Did you check the ground points of relais, injection and fuel pump?
Current has to come from somewhere

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I no longer have electrical diagrams for these things as I no longer own an L-Jet car but my memory is that there are diodes in the combo relay to prevent back feeds. Diodes can fail short circuit. Have you tried swapping in a known good relay?
 

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Discussion Starter #16
Tried original and have a brand new relay in it now. Took it out and put in my car, works fine. Cleaned all grounds we could find before and after engine install. Studied papajams color wiring diagram last night and I saw a couple of things I want to test. Fingers crossed
 

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Discussion Starter #17
disconnected lead from ignition switch to combi relay that energizes fuel pump during cranking, no difference. Swapped ecu’s again, nada. Possible related problem, all the injectors are clicking and negative side of coil flashes the test light when ignition is switched on but not cranking. No evidence of any rodent or other damage to harness
 

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Discussion Starter #18
Did some more testing. After triggering the fuel cranking, shutoff ignition, pump still runs. Used a test light on combi relay, pin 88a, the black orange to the afm switch and also the ecu had 12v. Swapped ecu’s, what else would keep it powered up?
 

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Discussion Starter #19
Boy is my face red. I”ll take comfort that I didn’t do it but should have caught it sooner. The 2 sets of 3 gnd wires terminated on the rear side of the passenger cam cover, well, weren’t. I saw 3 wires attached and then noticed 3 others pinched between the head and camcover not terminated. Loosened and pulled out, reattached, fuel pump issue seems gone. I wont be working on it more till next week when I get back from Florida but at least I won’t be worrying about it
 
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