I have a 86 4.3 TBI Monte I'm putting a 350 in. It has the 1227137 ECM, in it. I looked through my spare ECM's and all I have is a Truck 747 with the ARJT prom. I'm just using a 700 for the trans, so can I get away with the 747, or will it need a repin? I'm guessing I'll need a repin, and a prom from a Caprice or something.
Can someone point me in the right direction, the searches I've found aren't really covering the 86 side of things. I have a GM manual for the 4.3, that has a pinout of the 86 ECM, but that's all.

Thanks,
Scott.

 

Tough question. Note that there isn't a Caprice PROM for the '7747. Only truck calibrations are available for it. If you want to use a stock ECM the '8746 may be the best bet. It also uses an IAT which the '7747 doesn't.

The '8746 is a car ECM, with car features. It was used in the f-body's ('89 - '92) and Caprices (not sure of the exact years, but similar to the f-body years).

The only 350 calibration for the '8746 will be from a Caprice. The f-body TBI's were all 305s.

However, I can see that some tuning should be done.

Note that the '7747, '7137, and '8746 ECMs (among others) all use the same hardware. It is only the code that is different.

So for re-pinning you may find that some of the outputs are different. Such as the AIR solenoids, EGR and CCP. Check pins A2, A3, A4, and C1 and C2. The remaining pins are dedicated to that circuit and will match across the three ECMs.

RBob.

 

I'll start looking around for a '8746 car ECM. I agree that may be my best for ease of the swap. The service manual I have is for the B-G body. The B-G Body is the same pinout according to the book.



I'd guess the pinout for the 1228746 is the same, or real close. You say the '8476 was also in the TBI F Body, but it was a 305. Back in '89 a friend of mine had a TBI firebird, and it ran really good IIRC. I may try to find that for a start.

Thanks for the info.

 

I picked up a 1228746 from a 89 TBI Caprice. It has an APFN prom. I also found a ANLU .bin over on DIYefi. What .XDF for Tunerpro do I need for these???

Thanks!

Edit: I think I found it. (61 for 8746.xdf) at diy-efi.

 

APFN is a 305cid I understand. ANLU is the 350.