Where to find a prom for 7730 ECM (Page 1/2)
Gryffindad AUG 19, 10:40 AM
Hey guys,

I'm putting Jcirc's old turbocharged 3.4l in my Fiero and picked up a 7730 ECM (the engine was already wired for it) but I need to find a prom.
Anyone know where I can get one or the part number to search for?

Thanks
Dennis LaGrua AUG 19, 07:49 PM
We installed that 3.4L engine in Jerrys Fiero before he went turbo. I knew the previous owner of that engine before he sold it to Jerry. Later he went to performance shop and they installed the turbo kit and changed the ECM and I don't know what those guys did.
I believe the 7730 ECM used a 27C512 eprom that can be replaced with a flash memory chip 27SF512. Those part numbers are blank un-programmed memory chips. You would then need to program that chip starting with say a code from a 4.3L GMC turbo Cyclone and then tweak the program for your engine.Point is putting in a specifically programmed chip for that engine is what is needed.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Gryffindad AUG 19, 08:27 PM
Yep, glad someone is around from then! I appreciate the reply here. I've looked at as many of Jcirc's old threads on it as I could to get information on the engine and setup, I'm not a mechanic though I have a local shop working on it.
What I have is the 3.4L from Jcirc and the Remera from Txopie, the engine and transmission are in, new axle is on, and I grabbed 7730 pictured below. My shop has a programming guy who will be working on it, they've just been having me supply the parts though so I'm trying to figure out what I need exactly.

So it sounds like the 27SF512 chip will go in the ECM pictured below, then start with the 4.3L GMC Turbo Cyclone
Dennis LaGrua AUG 20, 03:38 PM

quote
Originally posted by Gryffindad:


So it sounds like the 27SF512 chip will go in the ECM pictured below, then start with the 4.3L GMC Turbo Cyclone




That's correct but if your shop starts with the Turbo cyclone program, have them make sure that the engine has a 2 BAR MAP sensor that senses vacuum and boost. The standard Fiero MAP sensor does not. The 7730 also uses a knock sensor and you will need the sensor and the ESC module that is essentially an A/D converter box. The sensor connects to the ESC module and the that goes to a pin on the ECM.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

jdv AUG 21, 07:05 PM
Moates has the hardware.
https://www.moates.net/g1-m...c-p-32.html?cPath=64
RacerX11 AUG 21, 11:15 PM
You need an entire memcal, not just the eprom chip.
Dennis LaGrua AUG 22, 07:52 AM

quote
Originally posted by RacerX11:

You need an entire memcal, not just the eprom chip.



Correct. Neglected to mention that but the Moates adapter allows you to use a reprogrammed eprom chip. Trying to erase and reprogram it while on the memcal is not the best way to do it.
Here it is with a zif socket that makes removal and insertion easy


------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

[This message has been edited by Dennis LaGrua (edited 08-22-2021).]

fieroguru AUG 22, 08:32 AM
If you tear apart an old ecm for the memcal connector, then you can add some spider legs to it that allows mounting the memcal base to the programmer and eliminates the need to remove the eprom chip every time you need to make a tune change. You do have to remove the stock eprom and install a flash erase version first.





Raydar AUG 22, 11:34 AM
Sorry to be a "stick-in-the-mud".

Tunercat shows that a 7730 uses a 27C256. Not a 512. (Can a 512 be used in place of a 256?)


quote
Originally posted by Gryffindad:
...then start with the 4.3L GMC Turbo Cyclone



The Syclone/Typhoon used a 7749 ECM and a 27C128 chip.

I have no idea about cross-compatibility of any of these pieces. But I wouldn't count on it.

All this info comes from http://www.tunercat.com/ under "ECM Definition Files".

Edit - I did find "$8F 1227727 89 - 90 Buick / Pontiac LG5 3.1L V6 MFI Turbo 27C256"
2nd Edit - It also appears that some cars used a 7727 and a 7730 interchangeably, using the same (different) code mask. So the $8F mask above may be able to be used in your 7730.

[This message has been edited by Raydar (edited 08-22-2021).]

fierofool AUG 22, 02:24 PM
Adding to what Dennis said about the knock sensor. Sinister Performance told me to use a knock sensor for the vehicle the 7730 ECM came from. In my case, a 91 Beretta 3.1. That's the knock sensor I purchased.