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?

 

....Faulty ignition?

 

so.. .you pull the key out and it stays on? i'd say its an ignition issue too.

 

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.

 

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.

 

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.......

 

http://personal.utulsa.edu/~nathan-b...lectrical.html

 

Sorry, that wasn't very helpful. Try this one:

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

Pull down eng3r.pdf.