I have been having problems with my '93 3000gt SL and keeping it running, sometimes it runs fine then others it idles low then cuts off, and help?


Asked by Nov 28, 2014 at 11:49 PM about the 1993 Mitsubishi 3000GT 2 Dr SL Hatchback

Question type: Maintenance & Repair

Lately, my 3000gt has been having problems staying running all of the time. At first I
thought that it was the ignition coils and replaced to set in the middle. After getting that
installed it still had problems running. For the most part my car would run fine but then the
idle would drop off to about 400RPM and wavier up and down before cutting off. After
trying to figure it out for hours and replacing the PTU with a new one as well. I figured out
that the wiring harness right above the ptu is what is causing the problem. I dont see any
visible damage to the harness but it seems like i can just wiggle the harness a little bit
before the car cuts off and the idle will go back to normal and the car will run fine.
anybody have any help please? i have to back at school this weekend and my car is the
only transportation there.

4 Answers


normally the waivering dipping, spiking, or hunting idle is the IACV but since you said what you did it sounds like your PTU isn't connected very well get that connected better and see if it helps if not let me know and ill walk you through diagnosing the IACV,, its not hard at all but will need a voltmeter

1 people found this helpful.
Best Answer Mark helpful

wow no helpful or best answer for that one either,, your so welcomed lol


My apologies, the question went for a little without an answe and by that time I was back at school without my car. Then when I came back during the summer the rear brakes rusted out so I had to work and get money to replace those all the while the idle and running of my car has been the same if not getting worse. I'm sorry I didn't get back to you in a timely matter but is really appreciate if you could help me with finding a better ground or connection with the PTU.


I had same issues. Changed ptu and iac. Car runs fine. Check all groumds clean em up! And clean up the throttle body and plate! May have adjust the air idle screw once the IAC is replaced, but remember to have the car at normal operating temps before adjusting stuff. Also make sure you tight the screws down on the iac but not over tight! I burnt out the first one cause i didnt get the screws tight enough causing the iac to have a intake leak around the rubber o ring. I thought i had it screwed in tight enough but when i bought another one i made sure i screwed that in till it felt secured enough with out stripping the aluminum hole. Worse case senerio larger screw if it didnt snap off in the hole

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