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Old 09-28-2008, 03:38 PM   #1
GMCRob
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Questions for Ls1 swap guys

I just finished up a LS1 swap in a 71 chevy truck and everything was working perfect exept my tranny wouldnt shift if you got on it hard, it would shift fine driving normal. well at the time my computer wasnt tuned yet so i figured it was that, Then the tranny went out so i put another one in it and took my computer to a guy and had my gear ratio and tire size changed and took all of the stuff i didnt need out. Well it is still doing the same thing, I am afraid of burning another tranny up. What else could it be, some kinda sensor or something , my computer is not throwing any codes, and the guy that did my computer does all the cars around here so i know hes good. Any kinda help would be great Thanks.
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Old 09-28-2008, 04:44 PM   #2
LEEVON
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Re: Questions for Ls1 swap guys

what tranny are you running? 4l60e or 700R4?
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Old 09-28-2008, 04:49 PM   #3
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Re: Questions for Ls1 swap guys

Sorry about that im running the 4L60E,
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Old 09-28-2008, 05:03 PM   #4
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Re: Questions for Ls1 swap guys

Call Jesse @
www.wait4meperformance.com and tell him what it is doing. Sounds like the speed sensor may not be acting right, but I am just guessing.
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Old 09-28-2008, 08:25 PM   #5
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Re: Questions for Ls1 swap guys

you did hook up the TCC wire right???? its the purple one that goes to the brake switch...
also you have the BEST tuner local to ya, in warr acres, his name is glen (hope he is the one you are useing)....
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Old 09-28-2008, 08:45 PM   #6
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Re: Questions for Ls1 swap guys

might be a question the guys over on the "Hybrid" forum on LS1tech can help you with. Lot more guys over there to pool from. One of them may have had the same issue.

Good luck!
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Old 09-29-2008, 05:58 PM   #7
GMCRob
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Re: Questions for Ls1 swap guys

Yeh glen is the guy i am using, and yes i hooked up the brake light switch. I took it out today and drove it a little and its not that it doesnt shift, it actually gets to about 5500 RPM and the tranny just freespins, kinda like it throws itself into nuetral. but only at wide open, just cruisin it does fine
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Old 09-29-2008, 06:03 PM   #8
68 short step
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Re: Questions for Ls1 swap guys

those sound ezactly like the symtoms of the TCC wire not hooked up, what year engine/trans are you useing? also whats it out of?
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Old 09-29-2008, 06:11 PM   #9
GMCRob
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Re: Questions for Ls1 swap guys

It is out of a 2000 SS camero, i am running a street and performance harness, I had a buddy put it on a scanner and it said my converter is locking up. That is the brake switch deal your talking about right
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Old 09-29-2008, 06:16 PM   #10
68 short step
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Re: Questions for Ls1 swap guys

yea, thats what it controls, the lock-up of the converter.....any mil lights??? also did you install a cam??
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Old 09-29-2008, 06:20 PM   #11
GMCRob
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Re: Questions for Ls1 swap guys

its a bone stock engine, the only codes is a front o2 sensor,
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Old 09-29-2008, 06:25 PM   #12
68 short step
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Re: Questions for Ls1 swap guys

hmmmm, my suggestion is to take it to glen, and have him ride along with you and he can monitor the eng/trans live and see whats going on.....

Last edited by 68 short step; 09-29-2008 at 06:25 PM.
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Old 09-29-2008, 08:31 PM   #13
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Re: Questions for Ls1 swap guys

Quote:
Originally Posted by GMCRob View Post
Yeh glen is the guy i am using, and yes i hooked up the brake light switch. I took it out today and drove it a little and its not that it doesnt shift, it actually gets to about 5500 RPM and the tranny just freespins, kinda like it throws itself into nuetral. but only at wide open, just cruisin it does fine
Nevermind the speed sensor then, let us know what you find out.
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Old 09-29-2008, 11:49 PM   #14
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Re: Questions for Ls1 swap guys

I don't know if it's the same on the cars, but on my 05 truck engine, I had to run a power wire to the transmission. It is part of circuit 1020 of my factory harness, so I just took that 1020 wire and ran it to a fused 10a pink hot lead and everything works fine. Something to think about?

The TCC is supposed to have 12v except for when stopping, so I used a 5-pin relay to switch the power from the TCC wire to the brake lights when I hit the switch.
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