frankrizz

Hey Guys,
Wanted to have my car dyno tested. Tech told me that he could
not make any changes to the pcm because for some unknown reason it was
locked out. I can only read data but not make any changes. He suggested
that I purchase an unmolested pcm. Anybody ever experience this? Any suggestions on a stock 94 Lt1 computer?

Injuneer

Do you mean "dyno tuned"? No one has to access your PCM to run it on a dyno to test HP.

Some tuners may lock the PCM, or maybe someone used a Hypertech tuner and never returned the program to stock.... not sure if the Hypertech would cause the problem.

You could check with someone like pcmforless to see if they can return it to it's original programmability.

If you need a replacement, 94 and 95 are the same part #.

Chimera96

OP

Given your transplant I suspect "someone" did some PCM adjustments and may have locked the PCM. Maybe not all tuners do this but mine has a sticker (96 Impala) on the PCM with a file # from the company that did it, Fast Chip (Ed Wright). If you have such a sticker identifying what company tune it, contact them with the ? on if it is locked.

Did you do the 38 Ford transplant or buy the car that way?

I am doing a Carb version of a LT1 with a SBC rear distributor in a 70 Nova so I just abandoned the PCM and wired the motor old school. It is a T56 though, not a "E" auto

Injuneer

The PCM is the same for all 94/95 models, whether they are manual or automatic. The program can be changed to match the trans.

frankrizz

I bought the car that way. Thanks to the Forum, I contacted Keith Wenzel from PCM for less. Sounds like he can help. I'd be interested how you would be able to convert the LT1 back
to a carb. set-up. I am kinda old school myself. Hey you never know!

Nice chatting

Chimera96

easy, GMPP makes the manifold and a block off plate for the TC where Opti went that has a Timing mark tab. I have a ATI balancer with timing marks

Manifold

Chevrolet Performance Carbureted LT1 Intake Manifolds 24502592 - Free Shipping on Orders Over $99 at Summit Racing

Opti block off plate

Chevrolet Performance LT1/LT4 Front Cover Plugs 12367600 - Free Shipping on Orders Over $99 at Summit Racing

shoebox

IDK why you would want to go back to carb. FI is way more efficient and infinitely more tunable.

Chimera96

Rob

in my case I wanted a carb motor in my 70 Nova. Since I had a LT1 I just converted it for that car along with a T56

I see various LT1 transplants in everything from rat rods, Tri 5's, etc and some are still FI set ups and some are carb conversions. Whatever one wants for their ride. At the end of the day the LT1 is just a SBC which can be set up both ways

shoebox

Yeah, I know. Just saying that if I had a running FI setup, I would not really want to go back to a carb.

Chimera96

yeah in the Op's case his 38 is already set up with the donor car PCM to run the FI and auto so yeah just keep it and the FI

I just wanted to keep my 3 wire old school wiring on the Nova. It was a factory 6 cyl car that had a new turbo 350 in it when I got it at a lien auction for $800. Since I had the LT1 from my Impala I just used it and went carb. Timing light, dwell meter and a screwdriver is all I needed to tune :-)

sold the auto and went stick

shoebox

I like 70 Novas.