Question about 1999 Mitsubishi Eclipse

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Random multiple missfires!!!!!

I rebuilt a motor and have replaced all the sensors, have had the engine put in time multiple times, replaced all vac. lines, coil, wires, plugs, and had another head and gasket bolts the whole nine yards, fuel pressure checked multiple times, and other then that i am at a loss.............................................. What could the problem be???????

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  • madracing Oct 19, 2008

    Its a 2.0 420a with a manual tranny.

  • madracing Oct 19, 2008

    non turbo

  • alex metro
    alex metro May 11, 2010

    if non-turbo, is it a 2.0L or 2.4L?

  • alex metro
    alex metro May 11, 2010

    Turbo or Non-turbo?



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  • Mitsubishi Master
  • 338 Answers

I have a 2gnt too but mine is a 98, i also have had 2 95 GSTs. I know pretty much everything on these cars so it shouldn't be to hard to get this figured out. I also have all of the factory service manuals HERE if you want to download them.
Well all of these are okay:

Spark plugs or wires failed
Ignition coil failed
Crankshaft position sensor failed
Fuel lines and filter failed
Fuel pressure regulator failed
Engine coolant temperature sensor
Timing belt tooth broken,
Intake air temperature sensor
MAP sensor
Front O2 sensor

Do a compression test, it should be 170-225 psi. If you have good compression you can rule these out.:

Worn piston rings
Worn valves
Head gasket failed
Cracked head


Posted on Oct 19, 2008

  • alex metro
    alex metro Oct 19, 2008


    To check the injectors, check the resistance between the 2 ternimals on the injector. it should be 11-15 ohms. Also check the o-rings on the injectors. last of all:
    Checking operation sound:

    Using a stethoscope or long blade screwdriver, check the operation sound ("tick-tick-tick") of injectors during idling or during cranking. Check that as the engine speed increases, the frequency of the operating sound also increases.

    lnjectors failed

    PCV valves are cheap. i would say replace it if you haven't already. they we can eliminate this:

    PCV valve failed
    If you haven't blocked off your EGR (alot of people do), just remove it and make sure its not stuck open. before you reinstall it, it would probably be a good idea to clean the carbon build up so the vavle can operate freely.

    EGR valve failed
    i would save checking the wiring last cause you probably find the problem somewhere else.

    Wiring harness and connectors failed

    other things to check:

    if you have a vacuum gauge, check the vacuum at the intake manifold. it should read 18 in.Hg or more.

    You should probably add a bottle of 'HEET' and/or fuel system treatment to your car, cause you may have gotten bad gasoline somewhere.

    (click for full size)



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