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Car cranks but wont start :(

Posted by 1990talondsm, Oct 8, 2010
Newbie Forum - Beginner DSM modification questions and discussions. Common, repetitive, and general discussions will get dumped here from other tech forums. Unless you're a Probationary member you shouldn't post threads here.

  1. 1990talondsm

    1990talondsm Proven Member

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    I was driving my car the other day and getting on it. When I let off and started cruising the engine just died. The timing belt didn't break and it is still in time. I am getting no spark and the fuel pump wont turn on but did shoot out fuel with fuel line disconnected and cranking the car. Does anyone know where the fuel relay is cause my Manuel doesn't tell me and how do you tell if your ECU is bad.
     
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  2. DSM1G90

    DSM1G90 Supporting Member

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    Pump does run when the starter is engaging - why you got fuel out while starting and stays on after the motor has started

    It doesn't say anything like that in the manual and I'm sure that your ECU took a dump .. like mine did when my car did the exact same thing-suddenly died at an intersection and had to have it towed home.

    -good luck . DSM
     
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  3. 1990talondsm

    1990talondsm Proven Member

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    Do you know how to tell if an ECU is bad or how to test a crank sensor. When cranking the car usually displays some oil pressure cause the motor is turning, same with RPM but it is not showing either.
     
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  4. VisegripMech

    VisegripMech Proven Member

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    If you still have the stock pretend "Boost gauge" hooked up, it should move to zero when you turn the ignition to on. If you remember it working before and now it doesn't move, it's probably the ECU.
     
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  5. chenk18

    chenk18 Proven Member

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    Or you could always open it and see if anything looks bad. And the fuel relay is located next to the ecu.
     
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  6. 1990talondsm

    1990talondsm Proven Member

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    OK I check the boost gauge and it is not going to zero. I have already replaced the stock fuel relay then. It was just called something else when I got the part from Mitsubishi.
     
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  7. hectorjr

    hectorjr Probationary Member

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    my car did the SAME thing. It was the Crank Position Sensor. it controls spark on these and most mpfi cars. id get one from Mitsubishi, hope this helps..:mrt:
     
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  8. steve

    steve DSM Wiseman

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    I think your talking about the MPI relay.

    When you first turn the ignition on the ECU should turn the CEL on for about five seconds and then turn it off. On the turbo cars it also moves the "boost" gauge pointer to zero and holds it there until you start cranking. While cranking the pointer should move to the vacuum side and if the engine starts remain there while idling, if the car doesn't start it should move back to zero when you stop cranking.

    If your ECU doesn't do this it's not running and it time to figure out why, nothing else interesting is going to happen until the ECU is working.

    There are a bunch of posts by me on checking the operation of the MPI relay as it applies to powering the ECU. Here's an example. http://www.dsmtuners.com/forums/newbie-forum/381070-ecu-problems.html

    If the relay is functioning then it's time to look at the ECU since the caps fail on all of them and can cause the ECU to fail.
     
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  9. 1990talondsm

    1990talondsm Proven Member

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    Thanks for the great help wise man. Ill check out your thread.
     
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  10. 1990talondsm

    1990talondsm Proven Member

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    I went and got a new 20 amp fuse for the MPI next to battery. When I turned the car on everything worked for a second then the fuse blew. Any suggestions where to start looking cause my Manuel doesn't give a good wiring diagram.
     
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  11. 91Bomb

    91Bomb Proven Member

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    Open ECU and look/smell on both sides of the board for burnt black gooey stuff leaking around the capacitors. This is a common problem for 1g ecu's that came with subpar caps.
     
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  12. steve

    steve DSM Wiseman

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    Blown ECU is one thing that could cause you to pop MPI fuses, but so can wiring shorts, bad MAF, bad CAS, or less likely problems with the solenoids, ISC, and injector resistors.
     
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  13. 1990talondsm

    1990talondsm Proven Member

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    I traced the wires from the MPI and non are split or shorted that I can see. I have a GM MAF so I will have to check the voltage there. I took the ECU out and where one of the capacitors is the is a little brown but nothing crazy. I will try to post some pics of it.
     
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  14. Tyeler18

    Tyeler18 Proven Member

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    Like stated. Sounds like your ecu is fried.
     
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  15. kawgomoo

    kawgomoo Proven Member

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    ecu is bad bud.

    the caps should be shiny, not discolored at all.

    trying rebuilding the ecu and see if that helps.
     
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