ur7x

Has anyone successfully swapped in a 2732 EPROM into a 1228079 ECM? Based on a few very old posts, it looks like this was successfully done on a 1226026 (Crossfire ECM) but has anyone done this with a 4 year newer Quadrajet ECM? My electronic guru guy I work with confirms that the 2732 pin outs in the following Will definitely work... and makes the chip look like 4 N82S181's. His only concern is that the N82S181 BPROM Chips that GM used are about 3 times faster then the 2732 EPROM Chip...(70ns response vs 200ns response) Has anyone tried this? Did it work? And one more question There are lots of threads on this forum that state the 1228079 ECM and the LG4/L69/ZZZ/ZZ4 MEMCAL Chips were 2716 EPROMs and others that say that these chips are 82S181 Bipolar PROMs... Which are they? Who's right?

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BMmonteSS

I'm sorry I can't help with your question although I do believe what you are trying to do is possible as the same strategy is used to run bigger (physically and electronically) 28 pin chips in TBI's with 24 pin chips.

If you don't mind me asking, what are you going to do once you are able to put a chip in the ecm? I'm not aware of any ecu files that available for the carbureted ecm's.

Fast355

I've got one on my laptop that I use with the carb cars. Originated from my 1988 Cadillac Sedan Deville Broughams 307 Vin9 CCC setup.

ur7x

You're right about that!

To date, as far as I can tell only two CCC Quadrajet ECMs have been hacked:
The Chevy 305 LG4/L69 (Camaro/Firebird/Monte/Caprice) 1987/1988 1228079; and
The Olds 307 LV2/LG8 (Cutlass, Regal, some Wagons, some 307 Caddies, Vista Cruisers, etc) 1988-1990 1228330.

I have the ECU/XDF/Tunerpro files for both. These files are NOT easy to find and for some reason aren't really posted anywhere (special thanks to members of this forum, Carb Hackers and Oldspower.com). I also have the BIN files for the 88 L69 Monte, 88 LV2 Cutlass and the two ZZ4 chips. My plan was to play with the ZZ4 chip and program into the 4 "quadrants" of the 2732:
1) Base Low output ultra low emissions from the LV2 (for my annual smog test)
2) Mileage/performance tune from the L69 (normal setting)
3) Factory Performance ZZ4 w/o ESC (scare the wife setting) and
4) Some crazy timing curve that I will try and dream up (it doesn't work setting ).

Fast 355 do you know if the 2732 chip is fast enough to emulate a N82S181 in this ECM? It looks like one of the guys on Carb Hackers tried this, but there never was a "final" "it works" (or it doens't work) post...

Cflick

My suggestion would be very similar to what would be done in other similar situations.
Build yourself an adapter out of a "standard" chip socket. ( I like wire wrap sockets for the longer, larger pins )
Add the resistors and jumpers on the socket, burn a stock chip, and try it. You'll know real fast if the access times and such are sufficient. I suspect it'll work fine.
If it fails, you'll find yourself in an ECM failure mode, but should still be able to limp home.
Better, take the stock chip on the ride, so you can literally pull over, and fall back on stock.

Lucid

This sounds pretty interesting.

I swapped my stock 86 LG4 ecm with the 1228079 1987 Monte Carlo SS ecm and the performance is so much better.

I would like to burn a chip with a custom tune, and willing to help if i can.

The prom code on the ecm was ACFZ, and i think its for the auto, but not 100% sure. (16069011 was the Part#)