I just replaced the crank sensor and the fuel pump relay as well as had the timing belt replaced. Now, when I turn off the ignition, the car continues to run. All the electrical circuits stay on and the engine continues to run.

It will do this until I unplug the ignition coil then everything turns off. Any ideas what would cause this?

 

The ignition switch most likely is bad. Not where the key goes, but the plastic part behind it.

 

so if the engine isn't running, and you switch the key from off to II (run) and back, everything goes on and off normally? but if you start it, then it won't switch off? odd, very odd... Only thing I can picture that would do that would be some kind of bad ground causing circuits to back-feed each other.

the fuel injection system is powered via that fuel pump relay (which is actually two seperate relays internally, one for the EFI system and ECU, and the other for the fuel pumps). to be more specific, the ignition key goes to the ECU, which in turn tells the fuel injection half of the relay to turn on, which powers the rest of the ECU as well as the injectors and stuff. it then also tells the fuel pump relay to turn on when the engine is turning...

power to the ignition coil comes directly off the ignition switch, pin 15R, to coil pin 15. 15R also feeds the ICU (ignition control unit) and the ignition power module.

even if the fuel injection relay was flakey and sticking on, this wouldn't be able to power the ignition.

UNLESS someone has done some electrical hackery on this car, then all bets are off.

 

Thank you both for the input. The situation pierce described is what is happening. If I turn the key from off to II, all the instruments come on. If I then turn the key back to off, all then instruments turn off. When I start the car and it is running, I turn the key to off (and even remove the key) the instruments stay on and so does the engine. Both do not go off until I disconnect the ignition coil.

What prompted me to replace the fuel pump relay and the crank position sensor in the first place was that the car would turn over, but never catch. Come to find out, the timing belt was broken. So I may not have needed to replace the relay and the sensor in the first place.

Pardon my thickheadedness, but to be certain, is it possible that the aftermarket relay I got was bad and that is keeping everything on or is that not even a possibility?

Thanks again!

 

definitely a possibility. I'll only use the OEM brand relays, the fuel pump relay is a Stibel.

 

We assume that you did not have this problem before you worked on the car. If so then you should retrace the steps of what you changed. If you have the old relays just put them back in a see what happens. Also when you pull the coil wire do you still have 12V at the coil. Just seems funny that the ign switch goes bad after you did the work. You might want to try tapping the relays after you shut off the key and see if that stops it. Also check the ign relay.

 

I did not have this behavior before I did the work. The car just would not start or run. The engine would turn over but never catch. Could you tell me the location of the ignition relay?

 

afaik, there's no ignition relay on a 240. greenbook shows ignition power as battery -> ignition switch -> ICU & Power Module -> Coil

the fuel injection IS on a relay, thats in the same relay module as the fuel pump relay (and is generally called a fuel pump relay, although it really should be the 'fuel injection and pump relay'.

 

Pierce hit the nail on the head, there was electrical trickery involved. Some previous owner had placed a jumper from fuse 4 to 5. This did not cause an issue before I replaced the fuel pump relay but did after the new replay was installed.

I removed the jumper and all is well, for now. Thanks to all for their help.

 

ahhh, so once the relay was enabled, and powering the tank pump, fuse 4 was powering fuse 5 which is normally powered via the ignition switch, so this kept the ECU thinking the key was on... when you killed the engine via the ignition coil, the ECU kills the fuel pumps, and poof, the ignition bypass vanishes.