1991 3.0 will not STOP running

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May 11, 2010 | 01:11 PM
  #1  
I replaced the fuel pump in my 1991 4Runner and now it will not STOP running, possible a person helping me hooked the battery up backwards for a moment while I stepped away. all ready disconnected the alt to check that it was not a diode stuck open, it is not. only way to shut the engine down is to unplug the negative cable. ANY ideas?
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May 12, 2010 | 12:06 PM
  #2  
....Faulty ignition?
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May 12, 2010 | 12:11 PM
  #3  
so.. .you pull the key out and it stays on? i'd say its an ignition issue too.
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May 12, 2010 | 05:16 PM
  #4  
Thanks for your replys.
I have allready replaced the ignition switch, and same situation. I put the origanal back in and was able to return the new one. Now it is behaving different. when I remove the key rather than running on, it stutters and misfires then stops after about ten seconds and I have a check engine light now, I am going to put a volt meter on the Batt and see if the alt circuit is shutting down when the key is removed. I belive it may be related to the ecu.
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May 12, 2010 | 05:18 PM
  #5  
Most likely ignition. When you turn it off and there isn't any more spark it should turn off dead. I mean it's not a diesel after all lol.
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May 12, 2010 | 07:47 PM
  #6  
Quote: Most likely ignition. When you turn it off and there isn't any more spark it should turn off dead. I mean it's not a diesel after all lol.
x2. Even if excess carbon buildup were causing ignition when the spark plugs weren't firing, we're talking about a fuel injected engine here. No power to the ECU and injectors means NO FUEL.

Get out the multimeter and electrical diagram and see if there's a short somewhere.
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May 12, 2010 | 10:49 PM
  #7  
I have been trying to find the Electrical Diagram, but, have yet to find one. I am thinking there may be a transistor in the ecu that is fried (stuck in the ON position) or maby a relay controled by the ignition switch which is "welded" ON, it seems as if the ignition is in the on position when it is off, I am boggled. I am going to meter out some circuits and seach for a diagram. I really value all your feedback, Thank you all very much, we will see what is the culprit.......
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May 13, 2010 | 12:28 AM
  #8  
http://personal.utulsa.edu/~nathan-b...lectrical.html
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May 13, 2010 | 12:32 AM
  #9  
Sorry, that wasn't very helpful. Try this one:

http://didnt.doit.wisc.edu/offroad/T...unne/systemci/

Pull down eng3r.pdf.
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