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1G Is there anyway to test an ECU?

Posted by tsiawd90, Jun 28, 2019

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  1. tsiawd90

    tsiawd90 Supporting Member

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    I have recently installed a new engine. I am not getting any spark and there is no voltage going to the injectors. I am assuming the ECU could be defective. Is there any way to test the ECU?

    Anywhere else you think I should look?

    Fuel comes out of the return line.
    No start, No spark, tested injector plug and no voltage.
     
  2. tk106

    tk106 Supporting Member

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    You can open it and inspect it. Do a search and you’ll see pics of leaking capacitors and burn drivers. Or, you can sent it to ecmlink and have them check it. IIRC they charge $35

    Not sure what else goes bad with them.
     
    Last edited by a moderator: Jun 28, 2019

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  3. Cherry

    Cherry Proven Member

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    I recently had a bad ecu if you want to see what capacitor leak looks like. I messaged ECMlink about it and never heard back if they could repair it or had any in stock or anything else.
     

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  4. tsiawd90

    tsiawd90 Supporting Member

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    I pulled it out and looked, the capacitors had been replaced but I don't know if the ECU ever worked. I did not notice any leaks, there was still some residue on the board. I have not had this car running since I bought it.
     
  5. jim95redgsx

    jim95redgsx Proven Member

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    A very basic test of the ECU is to turn the key to ON and observe the check engine light and the factory boost gauge. The check engine light should come on and stay on for around 5 seconds and then turn off. The factory boost gauge should go up to approximately 1/2 scale and stay there. A failure here could also indicate a bad MFI relay or main fusible link.

    The ECU does not control 12 volts to the injectors. This is supplied by the ignition switch as is 12 volts to the ignition coil and power transistor.
     
    AllanL and steve like this.
  6. tk106

    tk106 Supporting Member

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    Does the motor turn over? What happens when you turn the key?
     

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  7. tsiawd90

    tsiawd90 Supporting Member

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    Motor turns over but no start. I have fuel to the rail. I didn't see any spark.

    I am going to check fuses and the MFI. I'll try the basic ecu check today as well.
     
  8. tsiawd90

    tsiawd90 Supporting Member

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    The car is doing this check engine for 5 seconds and it goes off boost gauge goes and stays halfway.

    I did clean the board with a little alcohol but it made no difference.


    Still no spark.
     
  9. tsiawd90

    tsiawd90 Supporting Member

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    I think my issue is going to be a coolant temp sensor or the CAS. I'm going to try testing these tomorrow.

    I'm going to pick up a spare ECU and try it tomorrow but I don't think that will fix my issue.
     
  10. AllanL

    AllanL Proven Member

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    CAS was installed correctly?

    When you say 'no spark', how did test it?
     
  11. tsiawd90

    tsiawd90 Supporting Member

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    Not sure if the CAS was installed correctly. I need to look into that. I was going to take it off put the key in the run position turn it by hand and check for spark.

    Also I have the coolant light on when the key is on so I am suspecting the coolant temp sensor could also be an issue.

    I put a spark plug in the plug wire and put it on the exhaust manifold.
     
  12. tsiawd90

    tsiawd90 Supporting Member

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    Checked CAS it is good and still no spark no start.
     
  13. AllanL

    AllanL Proven Member

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  14. tsiawd90

    tsiawd90 Supporting Member

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    I'm going to double check, I could be off 180.

    I should still have spark even if that is the case though. I'm planning to test all the wires. I have another cas somewhere, if I can find it I'll try swapping it.
     
  15. AllanL

    AllanL Proven Member

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