I can not figure out what the hell is wrong with my friends 1991 240sx.
It starts and idles great but after 2-3 minutes of idleing it shuts off without any hesitation or sputtering. (By the way its a KA24DE). I checked for vacuum leaks, injectors are working fine, I checked fuel pump and fuel filter. I am thinking that it might be electrical. If anyone has had the same problem and fixed it please help a bro out. Thanks for any help in advance.

 

"tap tap" Is this thing on?
any help is welcome.
Thank you thank you very much
I'll be here all week, try the veal.

 

I'm thinking that it could be the ignition.

 

Run an ecu diagnostic first.
Then check the IACV system.

 

The ecu diagnostic showed the code 21, (ignition signal missing in primary coil) and code 13, (engine temperature sensor circuit). The code 21 showed up after the install of his 6al ignition a year ago and has had no trouble from the code.

 

Hmm sounds like the relay to the temperature sensor could be bad, I would also replace the temp sensor just in case it has never been replaced either (since the engine shuts off after 3 minutes or so?).
For the ignition signal I would check all connections and also make sure that the 6AL has proper grounding.

 

so could it be the temp sensor that is making it cut off?

 

Have you checked the Factory Service Manual?

 

When it shuts off its like someone turned the key off. It doesn't sputter or slowly die it just cuts off like the key was turned off. I cant figure it out.

 

You didn't mentioned if you....

 

Yes I checked the factory service manual but did not find much on ignition switch.

 

I had a problem a while ago with my car shutting off and it turned out to be a bad coolant temp sensor. It got so I couldn't go down the street to the gas station and back. I replaced it and now I can go to California and back if I wanted to.

 

I checked the coolent temp sensor with it out of the engine and the ohms reading is 1.791 k ohms and the with the element under hot water (running hot water from the sink) and it reads .853 k ohms.

 

I just tried starting it and it started just fine but still died after 2 min of idling, then I tried restarting it and everything electrical went out. I could not even get my keys out until I disconnected the battery and then put jumper cables on the connections to get my key out. Before I got my key out I tried jump starting it and as soon as I put the cables on the battery post it tried starting itself. any ideas about the haunted car???lol

 

Definitely a relay problem IMO