I was hoping that the computer from a stock '89 would work in my car. I have a 355 w/ a 276 cam, and headers. The scanner says the desired idle is 675. the car won't stay running at such a low idle. Is there any way to change the idle without burning a new prom?

 

I'm curious as to what scan tool you are using.I'm using a ATUO SCAN X-RAY.And I get that desired idle,and it is always differant never as low as what your getting but bounces around I'd like to know why



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1991 1LE Z28 355cu 5SPD (ORIGINALLY 305 BEST E.T. 14.186@99.86mph)NO PASSES ON 355 YET.MINI RAM INTAKE,AFR 190 HEADS,10.23:1cr 24# SVO INJECTORS,BBK 52mmTB,AFPR
FULL ROLLER MOTOR,1.6 rockers MSD 6AL
AUTOMETER A/F GAGUE MARCH PULLEYS,HEDDMEN HEADERS 3IN EXH NO CATS FLOWMASTER,POWER TRAX NO-SLIP LOCKER,3:42 GEARS,LAKEWOOD LOWER CONTROL ARMS HOTCHIKS STRUTTOWER BRACE,COMPETTION ENG.SUBFRAME CONNECTORS
MALLORY TACH W/SHIFT LITE
BLACK, TINTED WINDOWS, TAIL LIGHT COVERS BIG BLOCK COWL INDUCTION HOOD,SHAVED DOOR HANDLES

67RS 327cu 92K ORIG MILES.NEWER GM HEADS HEADERS,650 HOLLEY CARB,CAM, 350 TURBO TRANS W/SHIFT KIT&COOLER 12 BOLT POSI 3.73'S MUTLILEAF SPRINGS
NEW VINYLROOF&CARPET, COWL HOOD,HIDE AWAY HEAD LITES,

 

The best way to do it is with the PROM, opening up the minimum air will cause the IAC motor to keep trying to close which isn't very good for its life.