i am in the process of looking for a new car and i came across a 91 iroc that has a 6 speed in it. my question is will my 85 TPI motor work with the 91 computer or will i need to switch over my computer and wring harness? it is a very good deal and i dont know what do do. if the computer doesnt work with my setup and i do have to switch over my stuff, is it as difficult as everyone says?

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Brandon
"ScreaminDeamin 360"
350 60 over, TRW forged 9.83:1 pistons, crane cam 216/228 .484/.512, crane 1.6 RR's, ported plenum, home made ram air, 19 lb SVO injectors, crane AFPR

(a) be skeptical because there is no such thing as a 91 Iroc.
(b) 91 ECM will not work with 85 TPI, different harnesses too.
(c) With the motor out of the car it's not as difficult, but still a decent amount of work. You could do the swap in a weekend.

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-Bill
-=ICON Motorsports=-
Boston Chapter
91Z28, (in progress) 3.8L, TE63-1 turbo, MSD50lb injectors, Hemco upper, ported TTA heads, 62MM TB, Red's XP fuel pump, 3.73s, vigilante (stall to be determined)

i thought that 91 was the last year that they made iroc's. maybe he said 90 i dont know. wasnt really paying attention.

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Brandon
"ScreaminDeamin 360"
350 60 over, TRW forged 9.83:1 pistons, crane cam 216/228 .484/.512, crane 1.6 RR's, ported plenum, home made ram air, 19 lb SVO injectors, crane AFPR

90 was the last year for the IROC and they produced slightly over 6,000 of them I believe. It was around 6,400 i believe.

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TPI 305,
Gutted airboxes,
gutted MAF,
K&N filters,
Corvette Servo.
14.9@93mph

"Speed kills, wanna live forever, drive a Ford."

The engine itself will work with the '91 stuff....what is different is that the '90 or '91 ECM will use speed density while your '85 uses a MAF system. These systems are different however the engine will replace whatever is in there now if you ise the '91's sensors and harness. The only potential problem is if the cam you are using is "too radical" for the SD system to correct for, but a custom chip will fix that anyways. IMHO I would get away from using that '85 ECM....its the slowest and primitive of all the ECM's used....sort of like using a 386 in leu of a Pentium. HTH



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Tom
'88 Ragtop 379 SuperRam/Haltech EFI
'64 SS
http://home.sprynet.com/~ragtop88/main.htm

ok say i get a different MAF ecm will that work. like out of an 87 iroc or something.

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Brandon
"ScreaminDeamin 360"
350 60 over, TRW forged 9.83:1 pistons, crane cam 216/228 .484/.512, crane 1.6 RR's, ported plenum, home made ram air, 19 lb SVO injectors, crane AFPR

nope, can't do it.. wiring harness is different for MAF and Speed Density..

i wasnt referring to the wiring harness i was talking about the ECM itself. if i bought a ECM for and 86 or some other year that is MAF, would that work? what year did Speed Density first appear on Z28's and
I-Roc's?

Speed/Density first appeared on the Camaro, Firebird, and Corvette in 1990.