Author Topic: LT1 PCM  (Read 343 times)

BRDAPRY

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LT1 PCM
« on: May 30, 2018, 10:45:07 PM »
Hello all.  I’ve been working on this project for a few years now and it’s finally almost there.  I swapped in a 1997 LT1/LT4 with a 4L60E into my 80 T/A
Everything is finished and it’s running but I am having issue with either the PSI harness or the OBD1 PCM they provided me
  The car runs nice but still needs a dyno tune to get it dialed in for the LT4 hot cam, intake and heads.   
 The problem is that I have a check engine light “ to be expected” but when I hook up the OBD1 scan tool and turn on the key , the check engine light turns off and both electric fans go on full blast and no codes are flashed.   
  I sent the PCM back to PSI to have a look and he said it didn’t match the VIN of the PCM they sent me which is weird because that’s the only one that I’ve had in my possession other then the 1997 OBD2 from the donor car.     I sent back their back their PCM and he reflashed it and sent it back to me.  3 long weeks later I get to put it back in and still the same issue but on top of the the car won’t idle. 
  I’ve checked and rechecked my work and I KNOW I have the harness wired to their instructions. 
 Any ideas?   Im totally lost here. 

71455formula

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Re: LT1 PCM
« Reply #1 on: June 13, 2018, 06:10:29 AM »
Wonder if it is looking for a BCM?
1971 LS5 Formula. It's on the road finally!
2013 GMC Sierra 5.3l 6 speed Diamond White(sold)
2013 GMC Sierra Denali 6.2 6 speed AWD (sold)

Updated71

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Re: LT1 PCM
« Reply #2 on: June 14, 2018, 07:02:08 AM »
I had an issue with one of their harnesses on an LS swap.  It never ran correctly despite triple checking the connections and several back/forth re-tunes.  It was just a couple of weeks before their one year warranty/refund would be up on my purchase that I decided to send it back after all of the frustration.  I picked up a competitors harness and all was well. 
The surgeon general never said nuthin' 'bout smokin' the competition!

ryeguy2006a

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Re: LT1 PCM
« Reply #3 on: June 14, 2018, 02:08:35 PM »
I don't like to suggest spending other people's money, but you may want to look into the EFI connections 24x LS1 computer swap. It will convert the LT1 over to run the LS1 computer which is much easier to tune.

1976 Trans Am LS1, 6 speed, C5 12.8" Brakes, LS1 rear 12" brakes, 17" Aluminum Rims, and much more...SOLD
My Build: http://transamcountry.com/community/index.php?topic=24465.0

New project: 1968 Camaro with 6?.?0?  5.3 w/ Z06 cam/T56
http://transamcountry.com/community/index.php?topic=74591.0

Re: LT1 PCM
« Reply #3 on: June 14, 2018, 02:08:35 PM »
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