RiverMutant96

My 96 LT1 now has a failed PCM. I thought that it would be a good time to update to a tune-able unit. Maybe an LS style which would allow for a 24X ignition upgrade? Does anyone have any suggestions as to what would work as a plug and play replacement other than another 96 stock unit?
Thanks --Rob

Chimera96

a 24x conversion is not what I call "plug & play" on a LT1

PCM have "died" before but not a common problem. You can buy a 96 used one and have it flashed for your car by a aftermarket tuner or the dealership could put in a "stock" tune

shoebox

Are you sure you have a PCM problem? They rarely fail on their own.

RiverMutant96

Yes mine is corroded from the inside out, I think due to a crack in the bottom.
Also the 24X conversion kit that I found not only advertises as plug & play for Gen II LT engines, but they will load a customer supplied HPtuner base tune prior to shipment. unless you want to have the capability by adding the tuning software bundle to your order.
Actually the more I'm reading about these kits, I'm inclined to upgrade to the LS series gen 3 PCM as the price seems well worth it.
Check it out! TorqHead LTD
TORQHEAD LTD - HOME

Injuneer

The EFIConnection 24X system was the first one, and may be a bit cheaper, although less plug-and-play. Just a lot more people using EFIConnection, because its been around longer.

https://www.eficonnection.com/home/c...efi-24x-lt1lt4

RiverMutant96

Yeah Fred I started out with EFI connection, but they do not really show a kit for the whole deal. The Torqhead boys use the external reluctor with the hub which seems much more simple to install. The "works" full kit for $1550 is worth it,(in my opinion) to dump the opti forever!
Obviously I will talk to people from both organizations to fully understand the differences between them before I would shell out the $.
After that, I will have to rely on my Toolmaker instinct to guide me!
Thank you---Rob

Injuneer

If you haven't already found it, this thread seems to involve some of the earliest Torqhead buyers:

LTXTECH Forums

RiverMutant96

I have found the posts you are referring to, but I need to become a registered user to read them.
I do have another question for you Fred. Summit sells Chevrolet Performance replacement PCM for LT1 motors, but they list the years as only'94,'95. Do you think I could make one of those work on my '96?
Rob.

Injuneer

Do you have a manual or auto trans? Manual no problem. 4L60E may have issues. The 94/95 PCM can be programmed to run a 94 4L60E, with switched converter lockup, or a 95 with pulse width modulated (PWM) lockup. 96/97 also is PWM, but there are internal differences in the 95 trans and 96/97 trans that can damage the trans if the PCM and trans years don't match. See this thread:

LTXTECH Forums


94/95 is the OBD-1 PCM. All harness connectors and pinouts are the same, except for the items you can delete - see next sentence. You can run your 96 engine, but you will lose the OBD-2 misfire detection, and will not have PCM connections for the after-cat O2 sensors, crank position sensor, or EVAP system vacuum switch. None of those is required for the engine to run. Lot's of people swap to the 94/95 to get rid of intrusive OBD-2 emissions diagnostics, and use cheaper tuning software.

You would have to replace your 96 knock sensor (100,000 ohms) with a 93-95 knock sensor (4,500 ohms), or make resistance changes internal to the PCM.

Shoebox has a set of 95 PCM wiring pinouts, marked in red to show the 96/97 differences.

4th Gen LT1 F-body Tech Articles

KW Baraka

I just popped for one for my solid roller 398ci that's in my '96 Impala.

My tuner has installed the TorqHead and the EFI Connections. He likes the TorqHead WAY better! It's about as 'plug and play' as it gets.

KW

RiverMutant96

Thanks again Fred.
It sounds like I could make the older PCM work even though I do have a 4L60E in the car. I guess it comes down to how much I am willing to spend and dealing with the frustrations involved in getting the car to run again!
Rob