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Thread: 2004 Pontiac GTO L96 swap no spark

  1. #1
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    2004 Pontiac GTO L96 swap no spark

    Hi so I have a 04 GTO that I swapped a turbocharged l96 into and I hooked up a lingenfelter box to convert the cam and crank signals and now when I try to fire it up it just back fires every few seconds and eventually starts for a split second after about 15 minutes of cranking I have the correct cam and crank sensors but its not getting any spark until it backfires or starts for that split second and the customer also said he put an ls1 cam in this l96, so could that affect it? Im gonna link the a log file of me trying to start it and I will also link the tune so you guys can look at them and diagnose whats happening.


    log file 2004 GTO L96 swap turbocharged with lingenfelter box.hpl

    Stock gto tune from start of 6 29 25 - Copy.hpt

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    "It'd be a lot cooler if you did."

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    It has a custom cam gear thatll make it work in the l96, so the l96 gear set

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    So I guess the big question is what, if anything was done to disable VVT on this engine? Also, those converter boxes seem hit and miss on whether they actually work. On a side note, I can't imagine how that thing will handle with the extra weight of an iron block AND turbo kit in front. I hope suspension upgrades are in the budget.

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    Tuning Addict edcmat-l1's Avatar
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    Quote Originally Posted by chaseig15 View Post
    It has a custom cam gear thatll make it work in the l96, so the l96 gear set
    What is "custom" cam gear? What part number?

    Most of the time no spark is caused by no grounds on the back of the heads. Especially in any swap setups.

    I've never had any issues with the 58/24x boxes. I have 2 cars in here right now with them. Both run fine.

    Best thing you can do (if it's not loose grounds on the back of the heads) is pull the crank sensor and check the crank wheel. Pull the cam sensor and check that wheel. You need to find online pics of what each looks like looking through the holes if you don't know for sure, what they should look like.

    After the visual inspection you'll need an o-scope for the next steps.

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    Tuning Addict edcmat-l1's Avatar
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    Quote Originally Posted by gametech View Post
    So I guess the big question is what, if anything was done to disable VVT on this engine? Also, those converter boxes seem hit and miss on whether they actually work. On a side note, I can't imagine how that thing will handle with the extra weight of an iron block AND turbo kit in front. I hope suspension upgrades are in the budget.
    I've been telling C5 and C6 guys that for many years. Some listen, some don't. It's crazy how much an iron block changes one of those cars.

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  7. #7
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    Which one did you use? And did you change the timing chain cover to match the new gear?
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