NA2T Idle Control Problems

I am having similar issues with my newly converted NA2T and the idle. Maybe you have a bad or dirty valve. You could try removing it and cleaning it. Also, one thing to note… is your car an auto or manual? did your turbo valve come from an auto or manual? my valve came from an automatic.... now I have discovered that there is a valve for the manual AND the turbo car, each with different part numbers. though they look the same, I am not sure if the are any different as far as the manual or automatic car. so, it is possible that my valve doesn't work well because it came off an auto. maybe if I get the valve for the manual, mine will work better. I don't know. something to try. maybe yours is not hooked up correctly.

something else you could try is removing the idle valve, blocking it off and the hose going to the valve cover, and use the adjustment screw on the TB. see how well it idles and runs by doing that, and then decide what your next step is.

Good luck

Bon

Thanks for the suggestions bonfire, turns out its a wiring issue. Noticed the car was not going into closed loop mode, and upon investigation noticed I had forgotten to re-wire the 02 to turbo spec so this whole time it was as if the O2 was unplugged. The idle controls are tied into the O2 sensor and without a signal wont function properly. Going to do the rewire this weekend once the snow melts and all should be good

hmmm. that's a bit strange. see on mine, the 87 n/a ecu has the same zirconia sensor plug as the early turbo ecu had, so the turbo O2 plugged right in. but I never did the wire job on it. it runs the same weather its plugged in or not. since the conversion, my car has a tough time starting when cold. I have to crank it about 8 times before it will start and keep running. once it does though and warms up, it seems to run fine, idle fine, and start back up again. I can take it for a good drive and not have issues. but when it sits over night, crank crank crank she goes to no start. the weird thing is that it starts up better with my n/a ecu plugged in rather than the turbo one. I have another idle valve coming soon, so I will connect that and see what happens. also, the difference in the two valves is the manual has a spring inside it and the auto does not.
I'm not even real sure how to re-wire to O2 and it will be hard to explain that to my mechanic electrician (he's Afghani and I don't speak good Pashtu) so if I can figure out what goes to what, maybe I can explain it.
but is it really needed? again, my 84 turbo O2 wires match up with the car's 87 n/a harness for the bigger zirconium sensor.

glad you got yours figured out. I haven't been able to drive my NA2T since I got it back from the shop sadly.

Bon

While the plugs are the same, the way they are wired is not. The yellow wire of the oxygen sensor on the 87 is wired back to the ECU to pin 115.
But if you look at the 86 ECU, it doesn't have a pin 115, instead the yellow wire is grounded elsewhere. So essentially your oxygen sensor is currently unplugged.
You may not notice the car run any differently, but with the O2 unplugged it is most definitely running rich.
Found that out when I went for my emissions test last week and failed miserably. The car was running in open loop mode as there was no signal from the oxygen sensor

After I fixed the O2 wiring, my idle controls still don't function properly, so I'll be curious as to if yours will work with the new valve. Let me know what happens!

Well, I can do some reading on how to rewire it, but can you give a brief explanation of what I need to do? Would you mind? can you explain the open loop mode? what does that mean in electrical terms? even though emissions here are not strict like in the states, my car might still fail the inspection. I don't think the rewire will fix my start and idle issues, but it should at least not run rich and with the proper signal.

I just did some reading and I think I am not going to need to make the wiring change on the O2 sensor: according to the Z31 fuel system information resource, the 84-85 n/a and turbo cars came with the Zirconium and also the 87n/a. So if that is right, the 87n/a harness should have the same wiring as the 84-85 cars and no change should be needed. the three wire colors on my n/a sensor are white-black-white, and the harness colors are black, brown, and green with a yellow stripe. the sensor wire colors on my turbo sensor are red, white, and black. The sensor/harness must have been the change and didn't take place until 86, so I read. The yellow wire must have been part of that change. (Now if I choose to use my extra 87T ECU, I will need to change the sensor, bung, and the wiring.)

My valve was acting weird so I got another one still on the way. I also tried to test my aux air valve and when I put power to it, it never did close even after 10 minutes of being hot. it was open cold and stayed open warm. when I blew through it, I could feel the air coming out the other side. now its hard to tell which is going bad… but as soon as the new idle control gets on, I will let you know if it fixes anything. to add to my car blunders, I dropped a big flat head when I was pulling the air valve off and it went down right through my brand new radiator and punctured it. head slap… Doh! Just to add to my turbo project frustrations. no driving, another new radiator, and more work getting that dam front end removed…again.