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Thread: Truck has a hard time starting and when started, idle is very high

  1. #1

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    Truck has a hard time starting and when started, idle is very high

    So i just fixed the ecu, got the truck to not have misfire anymore, and it doesnt run rich anymore but at first i still have to use starting fluid to get it to start. After that the idle is very high and doesnt want to come down. any idea on what it could be or steps i should take on diagnosing the issue?

  2. #2


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    Please do yourself a favor and stop spraying starting fluid into it. If you do it too much, you turn your engine into what we call an "Ether Baby" (meaning it wont start without starting fluid). That stuff is helpful if you use just a quick squirt every great once in a while. Using it all the time can and often does mess stuff up.

    The fact that you have messed around with the ECU means there could be dozens of problems. However, you should start with the mechanical adjustments first. Things like idle speed are controlled by the BISS and the ISC. One is ECU controlled, and the other is set with a screwdriver. Base timing is also controlled mechanically. No ECU function can over ride a mechanical setting/function/issue.

    If your ECU was messed up before, chances are there were a few mechanical adjustments made to attempt to make the truck run better. You now need to go back and find them all to reset the basic operation. Your ECU could have been repaired incorrectly. Im not saying "you did a shitty job" or anything like that... What I'm saying is if you didn't put the correct components in, didn't put them in correctly, or they were shit components - the problem is not solved. There are thousands of variables regarding ECU problems. I always suggest to all of my clients replacing the ECU completely to eliminate all of the variables.

    Thats the best info I can give... There are too many things that could be causing everything to not work correctly.

  3. #3

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    I've only had to use it twice to get it started because once it starts the first time. It doesn't need it after that but I'll stop spraying fluid into that, I didn't know that could happen. Ill take your advice and start with the mechanical adjustments and checking sensors, still learning a lot about these trucks as this is my first one. Thanks for the Info!

  4. #4

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    Regarding the ECU I had it check over by someone at my work who fixes all of our circuirt boards and he said it all tests ok but we shall see!

  5. #5



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    Kind of hard to check a system board without the schematics that show voltages and Ohms and stuff. Hope he didn't charge you for that, lol.;

  6. #6

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    It was free lol

  7. #7



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    Did you ground the wire when you checked the timing? if not your timing will be off especially if the PO mucked with it to get it to run. There are threads on here that deal with the timing and how to set it. Also check the TPS - it may need adjusted as well.
    Pennyman1
    The best Dodge that Dodge never made
    Living the D-50 lifestyle since 1980

  8. #8

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    Quote Originally Posted by pennyman1 View Post
    Did you ground the wire when you checked the timing? if not your timing will be off especially if the PO mucked with it to get it to run. There are threads on here that deal with the timing and how to set it. Also check the TPS - it may need adjusted as well.
    For base timing with the belt or ignition timing? Tps is within spec, reads 5.4k ohm. Going to get a timing light and try to set it. also will look up grounding procedure for the ecu. Fixed idle by the way, idle adjustment screw was all the way in. lol

  9. #9

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    fixed the problem. Distributor was not aligned with the cam shafts causing it to be super advanced!

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