GM 502 Accel DFI Trouble c

Greetings to you all!
I've recently become the proud owner of a '93 Silverado pick-up truck. She has a 502 in there and an Accel supercharger, for the most part this is all good news. The problem however is that what I believe to be the ECM or perhaps what I should refer to as the DFI is 'apparently' of the PROM/EPROM type and according to someone who is more informed than me it dates back to 1987. Now if this is true, how would I go about diagnosing or possibly re-writing the contents of the Accel DFI? I was told I'd need a 386 or 486 computer and that it should be a portable one. This is slightly silly but still feasible, if I'd find the appropiate software then I'd be willing to try this approach. Does anyone have any feedback or possibly other suggestions? or perhaps someone has an alternative EFI system that's compatible with an early Accel air intake/super?
Any suggestions are welcome and will be much appreciated! If anyone likes, I'll happily provide photos of the on-board computers/wiring as well as of the truck or the engine & air-intake.
Thank you all in advance for your time & effort!

I would think the original computer for the 93 Silverado would have been the 16168625 with a 4L60E http://www.gearhead-efi.com/Fuel-Inj...Information-E6
or the 16196395 with a 4L80E http://www.gearhead-efi.com/Fuel-Inj...Information-OE

Is your transmission computer controlled?

dave w

This particular Silverado is a 3500 and presumably comes with a 4L80E (Thus I assume it's computer-controlled).
I don't have a diagnostic tool/ the right wires and hardware to connect to my 'Electronics Control Module'.
As of right now I cannot upload photos onto the forum, I'm uncertain as to why, file-size & format seem to be according to the guidelines. I hope I'm not being a gadfly here!.
I'll post photos of the ECM as soon as I can. I'm also not sure if the computer is original seeing as the engine and supercharger are not factory options!
Despite all this, thank you for your swift reply Dave!

The stock factory 1993 GM computer is not designed for Supercharger Boost. Typically, aftermarket computers designed to optimize Supercharger Boost performance will not control or operate a computer controlled Automatic Transmission (4L60E / 4L80E).

In my humble opinion (IMHO), to optimize the Supercharger performance the factory computer is inadequate and should be upgraded to an aftermarket system like Dynamic EFI https://www.dynamicefi.com/

The challenge is: Inadequate vs. Optimized computer controlled Supercharger?

dave w

Quote:

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Originally Posted by dave w

The stock factory 1993 GM computer is not designed for Supercharger Boost. Typically, aftermarket computers designed to optimize Supercharger Boost performance will not control or operate a computer controlled Automatic Transmission (4L60E / 4L80E).

In my humble opinion (IMHO), to optimize the Supercharger performance the factory computer is inadequate and should be upgraded to an aftermarket system like Dynamic EFI https://www.dynamicefi.com/

The challenge is: Inadequate vs. Optimized computer controlled Supercharger?

dave w

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You suggested a Dynamic EFI, could this EFI control the transmission and other electronics as well as the injection/supercharger? If not, is it possible to get two different computers that would work well together?

I finally managed to upload the photos. This is the casing of my on-board computer. How can I figure out if this box controls the transmission. Will I have to try and follow the wires or is there a better way of going about this?
Again, the aftermarket injection is from Accel.
The transmission is a stock 4L80E.
Attachment 13883
Attachment 13884

Interesting pic. I do not have experience with the Accel DFI system. A google search indicates the ECM you posted pics of is the DFI VI (6) system, which appears to be discontinued.

I'm guessing here, but maybe the 4L80E is being controlled by a stand-alone controller?

I think a good plan is to understand the Accel DFI VI system you have, before deciding a replacement fuel injection system is needed.

Hopefully the Accel DFI VI links below will help:
https://documents.holley.com/accel-d...ions_74022.pdf

https://www.amazon.com/Tuning-ACCEL-Programmable-Fuel-Injection/dp/1557884137

dave w

I bought a used Accel DFI computer and injection setup for my Camaro project for what I thought was a smoking deal! After a lot of homework I decided to ditch the Accel and go with Holley HP. The modern Holley computers are really nice and will save a lot of time learning if the price tradeoff is worth it to you. I decided for a big cam build like my car that the price was worth the ease of use.

https://www.summitracing.com/parts/h...-604/overview/

My $.02

there is no way that thing controls your transmission. the original ECM might be hanging around somewhere being piggybacked, or maybe your transmission isnt a 4l80e at all? you say you assume it's computer controlled. how many wires and sensors are on it?

you haven't even mentioned if the vehicle runs badly with the current setup, someone might have already done an alright job tuning it.

i say learn to tune the DFI system. i love antique crap. it'll be really easy on your wallet... if the software only runs on dos or something, who cares? people throw computers like that in the garbage.