Start signal wire and funky ignition questions, please help!

[Guest bastaad525]

Jersey - remember a while ago when you had the problem of your car running rich and that strange timing problem, and you found out some wire was hooked up incorrectly. Or anyone else that remembers how he solved this problem.... could someone give me a kind of 'walkthru' on exactly what you did? Remember, I didn't wire this conversion myself, so I dont have a good reference point to start from to know "oh, he's talking about this wire" so the more detailed you can go, the better. I need to know exactly what wire I'm looking for or how to distinguish it, where it should be going to or where I need to hook it to. I want to check this out on my own car and see if it's the cause of my problems also... the symptoms are definately similiar enough to what Jerseys car was doing. Just like his car... my car used to run okay, then suddenly now it runs rich, and the timing is acting not at all right, and the car is running pretty badly (though just like Jersey's car it still feels like it pulls pretty good). Help me out guys!

[yo2001]

I know, it should be a single yellow wire coming out of 8 pin connector. it needs to be hooked up to starter trigger wire on the ignition switch. It triggers cold start enrichment circuit for 30 sec or so for easy start. if you hook it to some other constant 12V, it'll never goes out of cold start circuit.

[Guest bastaad525]

One big thing I notice, an inconsistency between the way my car is behaving, and what Jersey said his was doing. With his car, he noticed that his timing would not change from it's idle position, as he revved the engine it would just stay put. And if I remember right, it was that symptom that was the biggest clue to his problem. Mine definately advances when I rev it, and if it means anything, it will do this with the TPS connected or disconnected. Also, his car was idling funky but seemed to drive fine, for the most part my car idles fine but misfires a lot when held at any rpm above about 1000. I went looking at the wires today but there were a lot of yellow ones So I left it be. Oh and I rechecked the initial timing today, still set at 20* at idle with the TPS connected. I rechecked the TPS for adjustment and to be sure it's working and it checked out fine.

 

AND, it's still having the incredibly odd problem of an erratic spark on cylinder #1. All other cylinders spark with 100% consistent rythm when at idle and if I rev the engine, but the #1 goes flash-flash-stop-flash-stop-flash... very erratic, and it seems to get worse as I rev the engine. I've changed the cap and rotor, coil, have installed the MSD6A, have changed plugs and wires, and just to be SURE tonite I swapped the #1 and #2 plug wires over (both at the cap and the spark plugs) and nothing changed, #1 still erratic. I've tried rotating the distributor around (which on the '81 turbo, does NOT affect the timing, but does affect orientation of the cap to the rotor) with no effect. During the 30 mins or so that I was messing around with it it would occasionally even out and seem to be perfect for a few minutes, at idle or when revved, then would go back to being erratic, w/o changing or moving anything. Sometimes it will be perfect at idle but get erratic as soon as I touch the throttle. I am so f'ing baffled by this....

 

Yo2001 - you said it's the yellow wire on the 8 pin connector? I looked up Jersey's post and he said it was the wire going to pin #9, on the same connector that the TPS runs to. By the way Yo I'll most likely be buying that MSD retard thing off you soon. Gonna start piecing together my Megasquirt and N/A dizzy setup. I hope

[mobythevan]

Look at the FAQ again and several posts down there is a wiring chart for the turbo conversion into a 240z. Plug 2 has two different yellow wires, one of them is the start wire you are concerned about. The other is an AC signal. From the haynes manual you can track the wires around the wiring schematic to figure out which one is the start signal, and then it should only get 12V when cranking. I hooked it to the solenoid on the starter. The only place for confusion is that there happens to be two yellow wires in the same connector. The first two times I fired my engine I had the signal hooked to 12V all the time and it ran soooo rich I have a permanent black circle on my floor a foot in diameter where the stock downpipe dumped. It brought tears to my eyes it was so rich and it wouldn't idle, had to give it a little throttle to keep it running. But if someone hooked it up to 12V all the time and then adjusted idle, who knows how it would behave, like Jersey's car I guess.

 

Anyway, study that wiring chart carefully, locate the three plugs it refers to, and the haynes wiring schematics. Then look the see where the mechanic hooked each of the critical wires.