I have installed a 3100 SFI from a 2001 Malibu and it is running rich. I have an 1227730 from a 92 Cavalier 3.1 Auto, Broadcast Code AWPB. I can't to get it to run leaner. I was on the J Body web site and talked about the injectors were changed in 2000 from Multitec 1 to Multitec 2 and the early ECM will not talk to the newer ( 2 Injectors). Something about high impedance and low impedance. Is this my possible problem and if so, is there any way around it with out changing the injectors?

CAB, I don't know about the impedence being any different but I do know that I had this very same problem when I swapped a set of 99 3100 injectors into my brother's 91 Grand Prix 3.1, to replace the leaking stockers. Well, appearantly the 3100 injectors are of a higher flow rate than the older units, the Grand Prix runs basically the same computer system that you are using now. If you put low impedence injectors in I doubt the engine would run. I believe you have the same problem I experienced with my brother's car -- the engine runs too rich because the new injectors flow more than what the older 3.1 computer is set up to run stock. My solution was to redo the chip in the Prix and adjust the injector size accordingly. I can do the same for you if you would like. PM me if you are interested.

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quote Originally posted by CAB: I have installed a 3100 SFI from a 2001 Malibu and it is running rich. I have an 1227730 from a 92 Cavalier 3.1 Auto, Broadcast Code AWPB. I can't to get it to run leaner. I was on the J Body web site and talked about the injectors were changed in 2000 from Multitec 1 to Multitec 2 and the early ECM will not talk to the newer ( 2 Injectors). Something about high impedance and low impedance. Is this my possible problem and if so, is there any way around it with out changing the injectors?

I agree with Darth, I doubt they are peak and hold injectors (low impedance). Peak and hold are generally used in large flow injectors. 38 lbs per hour and up. Measure the resistance across the injector pins, if it is 2-4ohms then they are low impedance, if 14-16ohms then high impedance. Low impendance injectors would burn the Fiero injector drivers up, or blow a fuse.......Paul