(1993 3000GT Base) Ok at first i was driving down the road and all the sudden engine started running rough. i got it home and changed out my coil pack. Ran great for about a day then i was driving down the road and my rpm's dropped out 3000 rpm's to 0 in about 1 second.. sometimes it would start back up right off the bat and sometimes it would take 5 mins or more but i got it home... went out the next day and when i tried to start it, it just cranks and doesn't try to fire up... then if i let it set for a min it will usually fire up but if i punch the gas it just tries to die... but if i let up on the gas it will then start to idle again.... after letting it idle for maybe five minutes. i can then punch the gas and it revs up fine but my engine light does turn on..i have tested my PTU for continuity....and tested ports 1,2,3 when engine cranking = .7mvthe PTU wire harness (1,2,3 was reading from .8-1.9mv) (#5 was reading 8v with ignition on which should be 5v according to manual)I have tested the fuel pump with the black clip tester built in the cari have disconnected the fuel line at the fuel rail and crank engine and gas comes out(i do not have a psi gauge)coil packs, plug wires, and spark plugs are maybe month oldi have look at the ECM for any discolor on it but looks like brand newi tested harness (B-14) for continuity which in the manual says it should read .67-.81 ohms but the all read 0 with ignition turned on. wire # XXXXX on this harness read 12v which i believe is rightlooking for help
Country: United StatesMake: MitsubishiModel: 3000GTYear: 1993Engine: 3.0 V6
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Hello!My name is XXXXXX XXX I can assist you with your question.Does the engine currently just crank over and not start or does it start up and run rough?Have you checked for codes in the computer?Does the engine run rough at idle, under a load or both?
the first few cranks it does not start, after a few tries it will then fire a little then die... crank it a couple more times and the it will start and idle rough. If you try to give it gas it will then dog down and act like it will die. once you let off the gas it will then rev up some and go back to idle.
If you you give it gas and it dogs down then you let off the gas and it rev up some on its own then you get back on the gas as it revs up it will then rev up and sound fine
then as soon as you let up on the gas and it idles it doesnt wasnt to rev right again
no i havent had a computer on it for the code...
Ok.. if you can get it to idle at all, check to see if all cylinders are getting spark. If your engine is running rough, some of the cylinders may not be getting spark. THis is actually pretty common on this vehicle. The ECM drivers may not be sending a signal to the coil to allow for spark to all cylinders. (my experience has been cylinders 2 and 6).Another thing you will want to check is engine vacuum. The timing belt may have jumped time or loosened up causing this condition.Some other possible causes are a bad TDC sensor (engine speed sensor) or even a bad mass air flow sensor. If you need some more information on the engine vacuum, just let me know and I can post you a chart explaining what are the different engine vacuum readings and what they mean.
i will check these things asap. i am a second shifter so it may take me some time to get around do do all of this..i did pull the spark plug wires off individually and all of the coil ports was sending spark thohow do i test if the sensors are bad?? and how do i test the vacuum?
On this vehicle, the only accurate way to test the engine speed sensor is with a lab scope. The computer sends out a reference voltage to the sensor with the key on and when the engine is running. As the sensor goes around (cranking the engine over and with the engine running) it will pulse this reference signal to ground and send it back to the computer. It is an on off signal EXTREMELY fast. A voltmeter will not be able to get a good clean reading. So just keep that in mind.. if we don't find anything else, it could be this sensor. You could just replace it or pay someone to test it.You can check engine vacuum by using a hand held vacuum pump/tester. You hook it up to a vacuum line that has FULL manifold vacuum and take a reading.