tpiselli

iTrader: (1)

I'm trying to restore, as close as possible, the engine/ecm harness of an 88 GTA and I have a few of questions:
1) How long should the pink and white coil pigtail be? This is the pigtail with the gray coil connector. I literally have 3 feet of pink and white wire now for that pigtail which I know isn't correct. I'm thinking it should be a foot or less but I'm not sure.
2) For some reason the O2 ground circuit (#413) was tied down to the thermostat housing, had multiple splices in it, and was pinched under a valve cover. Looking at some wiring diagrams this ground should be tied into circuit 450 which is an engine ground. Can someone please let me know where this ground is located. I think it should be on the back of the driver side cylinder head but I'd like some confirmation.
3) Does anyone have a picture of how the coil and egr solenoid are mounted? I don't believe these were correct on this car.
Thanks,
Tony

Chevy86 IROC-Z

iTrader: (17)

1. The pink wire shouldnt be a concern. But it would be wise to cut it down shorter just so that it doesnt get in the way if you need to fiddle behind the engine.

2. O2 sensor? I dont know buddy. My IROC has the 1 wire type sensor.

3. EGR Solinoid should be mounted something like this (inside of the head towards the rear. My 86 IROC is mounted the same way but on the passengerside. Check picture.

tpiselli

iTrader: (1)

Thanks for the information and picture. I also have a one wire O2 sensor but the ECM actually uses two wires: one wire, termed the O2HI, is what has the sensor on it, the second wire, termed O2LO, is a ground for the ECM. On my car this ground is hacked pretty bad and I'm just looking to get it back to stock.
T-

Chevy86 IROC-Z

iTrader: (17)

Well according to this 1988 5.7 TPI wireing harness diagram, it just shows the one wire that goes straight to the ECM. Im not sure about the O2LO wire.

Chevy86 IROC-Z

iTrader: (17)

Here is a more clearer pic of the wiring diagram.

tpiselli

iTrader: (1)

Is that the wiring diagram from AutoZone? I've seen them before and never noticed they are missing this circuit. Here are a couple of diagrams that show the O2 ground wire at pin location D6. Both of these are from the 1988 Firebird service manual. The one shows this wire is tied to another ground which my wire isn't at the moment.

Chevy86 IROC-Z

iTrader: (17)

Wow. never knew that one. No its not Autozone. I found it while surfing the net about 6 months ago. Im not sure how different it is to a GTA but It is very similiar, if not, a diagram for the IROC-Z. As for the ground, all you have to do is look for the grounding strap (braided strap) that is connected from the engine or cylinderhead to the car body or frame. Unbolt the grounding strap either at the engine or the car frame/body. Now cut the wire (O2 Ground wire) and put a terminal connector along with a star washer. now put the freshly crimped terminal (make sure the eye of the terminal is large enough for a bolt to slide in) through the bolt that holds the grounding strap and bolt it in so that you'll have the O2 sensor wire "engine grounded." Be sure to cut the exposed wire in half where the o2 wire was previously connected so that you can insert some "heat shrink tubing" prior to twisting the wires back (I'd prefer to solder the wires together to get a solid connection). You may need some extra wire to reach the engine ground. Sound confusing?

tpiselli

iTrader: (1)

Nope, sounds good. I've fixed a few wires for this harness already and I've soldered each one and used heat shink tubing as well.
Thanks again.

Chevy86 IROC-Z

iTrader: (17)

Coo. Hope everything works out for ya. Peace.