Won't Start after Changing wires HELP

Discussion in 'GM Powertrain' started by KyleZ71, Jul 17, 2013.

  1. KyleZ71

    KyleZ71 New Member

    I put on a set of pro form valve covers today, and since the coils get moved away, I had to get longer wires (MSD) for they are mounted on top. After getting everything mounted and plugged in, the truck will not fire. It turns over but simply will not fire. To me it seems like the wires are too taught, and that could be preventing the spark. I also thought that the coil packs are out of order but I thought the packs themselves don't have a order. What do you guys think?
  2. Pikey

    Pikey Moderator

    wires too taught would not cause the issue, unless the ends are not making proper contact. coil packs can not be out of order. I would look for a disconnected harness somewhere, like the harness for the coils
  3. KyleZ71

    KyleZ71 New Member

    I know the harnesses are connected but not the ends... now I'm gonna plug a wire in to each wire and see if they spark
  4. Pikey

    Pikey Moderator

    if the connectors are not getting down into the coil holes then you will not have spark. Well, you might have spark, it just will not travel thru your wires. Most the time you hear a significant click noise when you push the wires into the coil. You might melt a standard wire if you plug it into the plug wire. I do not suggest doing that. I would pull a spark plug out, plug it into a wire and set it against the engine block and crank it to check for spark.
  5. KyleZ71

    KyleZ71 New Member

    Got spark, got fuel (can smell) but still no start. Everything is hooked up, and grounded. :neutral:

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    Guess ill bite the bullet, again, and take it to the garage.
  6. tbplus10

    tbplus10 Moderator

    You relocated the coils, are they properly grounded where their mounted at?
  7. KyleZ71

    KyleZ71 New Member

    Yes, I have one bolt fastening them to the bracket that sits on the top side of the valve cover. Didn't think this would be so frustrating
  8. KyleZ71

    KyleZ71 New Member

    Ok it has been one week since the truck was picked up and taken to a local repair shop. The mechanic said that the wires were not long enough and the accel wires were not the correct ones. SO after ordering a custom set of MSD LS wires, the mechanic said the truck STILL will not start. He said when hooking it up to his computer it reads misfire but won't say where. He said it could be too much fuel in the engine, bad coils, or bad ECM. So frustrated right now because I do not want to try to lets replace and see what works game. Do you guys think it would better to get it towed to the GM dealer as they're computers are better and mechanics are better trained?? Please help
  9. Pikey

    Pikey Moderator

    I still think that for it not to start something has to be disconnected. Maybe a knock sensor. If you don't feel comfortable with the place it is at then by all means take it somewhere else. If it ran before you did the valve covers then I highly doubt that the ECM happened to go bad at the exact same time. I also don't think that all your coils went bad at the same time. did the coils have more than one bolt holding them down before you changed the covers? Are the covers painted? I am leaning toward your coils not being grounded well. You could always take 8 pieces of wire with alligator clips on the ends, clip them to the coils and then clip the other end to a good ground point. If it works then you found your issue.
  10. KyleZ71

    KyleZ71 New Member

    Thanks for the response Pikey. I know for a fact the knock sensor were hooked up because that was my project only days before. The packs did have two bolts holding them on but the remount kit would only allow me to use one bolt. Maybe that's the problem. When changing the valve covers and gasket I read that it is not uncommon for oil to get on the plugs themselves. I did not pull the plugs, only putting a spare on each wire itself to ensure a spark. Hoping just oilly plugs. I too agree that all 8 packs shouldnt go bad at once and the same with the computer.
  11. tbplus10

    tbplus10 Moderator

    I agree, Im still stuck on the grounds, especially after the mechanics report.
    Are the new valve coverrs properly grounded, the hold down fasteners didnt have insulators or excess gasket material stopping them from grounding did they?
    Ive seen issues similiar to this due to inadequate grounds on the coils.
  12. KyleZ71

    KyleZ71 New Member

    To my knowledge no there wasn't any insulation, just metal on metal, but then again I haven't been under the hood of my truck in a week.

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    Well another day goes by without the truck. Hate that I have to call each day to find out the status
  13. KyleZ71

    KyleZ71 New Member

    Almost after two weeks I am now leaving to get the truck back. Here something in the wiring harness to the packs got messed up. Just glad to be able to drive it again. Hope I don't pass out when I see price
  14. Jaele

    Jaele Member

    dying to find out what was wrong.... and see the price tag lol
  15. KyleZ71

    KyleZ71 New Member

    He said the coil pack sub harness was messed up and needed to be replaced. Price tag was 633.99, that was after complaining about the time it took. That was two thirds the price he would've charged. Said it took 7 hours. Needless to say the garage took advantage of me, royally.
  16. TRPLXL2

    TRPLXL2 New Member

    Oooh that sucks!!! But look at it this way, at least he found it and got it running. The Chevy dealer would have charged at least $1,000 if not more, fancy tools don't make a better mechanic IMO.
  17. KyleZ71

    KyleZ71 New Member

    I don't know, I was thinking it would've been cheaper. The day before he finished the job I called Apple Chevrolet up to check about them taking on the project and they said that the wiring harness was most likely the problem and would be the first thing they replace.

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