I just recently began participating in message boards on this site, as my 1988 GMC 1/2 ton truck 350 TPI conversion is now running and seems to need help. The system I am using is from a 1987 Firebird GTA with an automatic transmission. My engine is running extremely rich and constantly delivers code 34, even after the memory has just been cleared and only the ignition is turned on. I wired the system based on a 1987 350 TPI wiring diagram, and have a fully functional ALDL. The ECM which came with the engine is GM part 1227747, which, as I have been told by the GM parts people, is a truck ECM. This is also mentioned on the message board archives on this site. The ECM is equipped with PROM "ACSU". Neither of these is correct according to the ECM lists I have seen for F-body cars, but the 1227727 is apparently usable. There was some mention in the archives of swapping wires for terminals A11 and D2, which, I believe, are connected to the MAF and relays. If I were working according to the standard 1987 wiring diagram, might I have connected these wires in a manner not appropriate for use with ECM 1227747? Also, since I am very new to TPI electronics (and most electronics in general), I would be interested in hearing why a truck ECM would function in my vehicle, and why it is desirable. Immediately, I suppose the most important thing is getting my MAF to work correctly within the system. I would greatly appreciate any suggestions. Thanks.

 

1227747 is for a TBI application
87 F Body is a MAF apllication, and uses a 1227165 ecm.

A better answer is using a 1227730 and delete the MAP and wire it up as a 90-92 system. Is work thou

The 1227727 is a water resistant version of the 1227730 and uses **odd** ecm connectors.

Might visit the DIY_EFI.ORG site and read all you can from gmecm