ok, i have a 87 iroc-z.
well here is my problem that im having.
the sucker runs perfect UNTIL i either click on my headlights, or fans. anything thats draws power kills my idle.
i had the batter and alterntaor checked. both were good. but i had a battery and alternator put on anyways. and did the same thing. i also put a new computer in.\im running outta ideas here!. all wires are perfect all connections perfect!.
im open to anything.
later guys


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1987 IROC-Z
355ci, Dart 2.02x1.60, compete forged bottom end, SLP siamesed runners, fully ported Edelbrock manifold and plenum, 58mm TB, Accel 26lb Injectors, Edelbrock headers & y-pipe, Flowmaster 3" cat-back, Rebuilt 700r4, B&M Megashifter, Holley 255lph fuel pump, triple guage pod, !A/C & Heat, !Smog pump, bypassed TB, MJS Ram air, custom PROM, Lakewood control lower control arms, Lakewood adjustable pan hard, Sub-Frames, Hotchkis Strut tower brace, Adjustable Torque Arm, 150hp NOS
IROC Pix

 

Check to see if your alternator is actually charging. Hold a steel bladed screw driver behind it with the motor running. It will pull it toward the alternator if it is in working order. Some of the auto parts stores will do a quick alternator check for you to see if its ok. You may want to check that out. Are you using power pulleys??

I had some shorting problems on my 86 IROC that I could not find. My final solution was to buy the coiled wire cover in different sizes and cover every dang wire that I could find. Look behind your distributor and see if you have wires chafing on the fire wall. Many of us do. That totally cured my short (gauges were shorting)

Just a final note, my buddy once fixed a car with a shorted wire under the carpet. It killed the battery every few days. Could not find it until he put an amp meter in line with the system and jacked up one wheel. The car was fine while sitting level, but it had a short when the chassis flexed. Good luck.
Jess

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Blue '86 IROC, 305 TPI
Ported Plenum, gutted air boxes, SuperChip, KN filters, TB Airfoil, transmission cooler... more to come. Not raced yet. 70,000 original miles. Owned since 1992.

 

Have you checked all the ground connections, battery? and starter? and alternator?
Are you running under drive pulleys?

 

every connection is tight and clean. alternator,battery,and starter.
and i dont have underdrive pulleys.
like i said i put a buddies alternator on my car and it did the same thing.
one thing tho, when we put his computer in my car it ran good. so i went to the store and bought one. and yet it still does the same thing?

 

k, went to go start my car 2day. nothing!
didnt even click or anything. any possiblity that my starter is giving me all the problems?

 

To me it sounds like you blew the fuselink for the alternator output wire. I can't remember where it's at on your car, on mine there's a terminal on the side of the radiator support right next to the battery where the alternator wire goes to and connects to 3 or 4 wires, one going to the battery. Try to find the terminal and check all the wires. Better yet follow the output wire from the alternator until you find the other end of it, take it off, and check it for continuinity (I know it's spelled wrong, but I'm tired.) You can do this with a DVOM (or a Fluke meter as some people call it) or just test it with a light bulb and a battery.
Come to think of it I actually had this problem about a year ago and it turned out to be the wire.

Joe

 

BTE if it turns out to be the wire, replace it with the correct replacement, don't bypass the fuse, it's there for a reason.

 

the only known fuseable link that i know of, was mounted to my fender. and that did blow on me, and it made my fuel pump not work.
so there would be another?


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1987 IROC-Z
355ci, Dart 2.02x1.60, compete forged bottom end, SLP siamesed runners, fully ported Edelbrock manifold and plenum, 58mm TB, Accel 26lb Injectors, Edelbrock headers & y-pipe, Flowmaster 3" cat-back, Rebuilt 700r4, B&M Megashifter, Holley 255lph fuel pump, triple guage pod, !A/C & Heat, !Smog pump, bypassed TB, MJS Ram air, custom PROM, Lakewood control lower control arms, Lakewood adjustable pan hard, Sub-Frames, Hotchkis Strut tower brace, Adjustable Torque Arm, 150hp NOS
IROC Pix