Engine won’t shut off??

[Whidbey Goblin]

So it’s been a while since my first start. I’ve hooked up several more systems including the cooling for the supercharger. I wanted to run the car again to make sure I don’t have any leaks. I let it run and come up to full temperature. When I went to shut it off it took a solid three seconds for the engine shut off after I turned the ignition off. Has anyone else experienced this?

 

[Vwsaabvt]

Engine doesn't stop when you turn off the key.

My issue is that it take 3 second for the engine to die after i shut off the key?

dfkitcar.com

pm me your address and Ill send you 2 diodes tomorrow

 

[Whidbey Goblin]

Engine doesn't stop when you turn off the key.

My issue is that it take 3 second for the engine to die after i shut off the key?

dfkitcar.com

pm me your address and Ill send you 2 diodes tomorrow

Where do the diodes go? Is this a common problem?

 

[Ross]

This comment says to put it on the heat exchanger fan.
If you unplug the heat exchanger fan, does the problem go away?
If so, cut the positive wire, put the diode inline. If the fan doesn't turn on, you have the turn the diode around, as you have the diode in backwards.

 

[Gtstorey]

Another option would be to add a relay that is closed by the current positive feed. Should be pretty simple since the battery is so close.

 

[PHENDERSON]

I had the run on issue and it was fixed with the diode on the Pos line to the HX fan, stripe towards the fan.

 

[Robinjo]

Since my harness is out of the car, should I just add a diode in the HX wire? Will it hurt anything if it wasn’t required and I used one?

 

[Gtstorey]

It won't hurt anything.

 

[Robinjo]

It won't hurt anything.

great, thanks for the info.

 

[Chubbs]

Where do the diodes go? Is this a common problem?

As others mentioned, most people need it on the heat exchanger fan. I needed it on the intercooler pump (LSJ). I wasn't even running an HX fan, and my car also wouldn't shut off. A diode on the IC pump fixed it completely.

Yes, it's a common problem. Super weird too. I have no idea why it's a problem on the goblin but not on the stock car.

 

[PHENDERSON]

I also had the problem (LSJ with HX fan) and putting one on the positive to the HX fan fixed it. There is a link somewhere in here to some diodes on amazon, those are what I used.

 

[TravMac]

Does anyone remember which original wire was intended to be extended for the HX fan? Since it's an extended wire, would there be a better solution for wire harnesses in the future? It's funny that I've had this issue too and didn't realize it had a "fix" to it until this post got traction.

 

[Gtstorey]

You can always have the wires just open/close relays to prevent the feedback power. That's how I wired my heat exchanger fan and pump, although I think the radiator fan is powered off the original circuit.