Car dies in less than ten minutes

[ProjektChrysali]

I'm having an issue with my GS-T where it will run beautifully for maybe ten minutes, then sometimes misfire for a moment, and die. Sometimes it will restart, but only run for a few seconds. It seems to consistently happen shortly after the car switches to LTFT and the car is at ~190 degrees. I'm wondering if there's any way to get the car to stay in STFT, and if there are any sensors or anything like that that trip at such a temperature. I know the radiator fan should turn on at 205, but the car always dies before the fan can even trip on.
Thanks in advance,
-Will

 

[sniver]

Power transistors for coils are infamous for working cold and stalling or erratic behavior hot. Had one go bad on my n/t 90 eclipse a while back.

The preliminary check would be to see if its fuel or ignition related. Next time it doesn't start get out and pull a spark plug wire ,stick a insulated screwdriver in the boot, and position it so the metal touches nothing, but stays 1/4 inch away from the point where it can ground. Have a buddy crank it and see if it looks like its sparking. If not, at least we know where to start.

I'm downloading the 2g FSM now, I'll post how to properly check it asap.

Other thought could be the coolant temp sensor.

 

[2GFWDbeast]

Could also check your maf. Make sure all the honey combs are together. Also you can buy maf cleaner from autozone and clean it.

 

[ProjektChrysali]

I've already replaced both the power transistor and the coolant temperature sensor. The problem persists if I swap in the other, and both check out with a multimeter. Neither coil seems overheated to the touch, but the recommended way would be a convenient way of testing while the engine is warm. Thanks sniver!
I had never heard of MAS cleaner but this seems like a good idea. In my logs my airflow seemed very low (<1 LB/min at idle) and the car is subject to a lot of dusty conditions. Unfortunately the stuff the local Autozone stock says DO NOT use on Mitsubishis, so I'll have to try somewhere else. The honeycomb is intact. Thanks 2GFWDbeast!

 

[lilrob2069]

had the same problem, turned out to be my ecu, after i was swapping parts out, i grabbed an ecu laying around with the same part # and it fixed it. just a possibility.

 

[sniver]

The ecu would be a very good possibility if it was a 1g. 2gs don't seem to have many ecu issues, but it sure sounds like its where its leading us.. Any local dsmers that you could borrow a ecu from to see?

You could wire is a potentiometer inline to make the car think its not quite warmed up yep and force it into open loop, eliminating the switch to any fuel trim. Issue being is its nothing more than a testing solution to see if its indeed related to closed loop.

Clean both battery terminals,make sure they have a good connection. Also check your engine/ecu grounds.

 

[2GFWDbeast]

only reason i say mas because i had the same problem as you. I took it and checked and a honeycomb came apart and was hitting the sensor

 

[sniver]

Mas doesn't equal maf. You had it right last post. And you can't use mas cleaner, on a maf either.

 

[ProjektChrysali]

Ended up being the Crank Angle Sensor.