Still having idling problems

[JustAnotherVictim]

Ok so I changed and adjusted the tps on my car and thought the problem went away, it was giving me a code "51" before. So it was idling a bit high so I figured I'd just adjust the idle speed, which did not work, turns out the isc valve was stuck in an open(sticking out) position. So I started it up after changing the valve with another I had that works and it starts pulsing and surging around 2k as if it can't make up it's mind. So now it's throwing a code "11"

11 ECU(+B)
Diagnosis
* Momentary interruption in power supply to ECU.
Trouble Area
* Ignition switch circuit
* Ignition switch
* Main relay circuit
* Main relay
* ECU

So I figure I'll go with the cheapest fix first being the main relay if I'm correct, I really don't want it to be the ECU since I'm in the works of getting a gte swap going, Hate to spend money on that right now. Now if the car is starting it shouldn't be the ignition switch right? It starts fine just the idling is erratic.
Any ideas or suggestions are apprieciated.

 

[JustAnotherVictim]

This morning I disconnected the efi fuse to reset the codes to see what would happen, so I start it up and it idles high. No matter how much I adjust the idle screw in or out it stays the same. I checked the codes and now it's just fast blinking. So I'm going to pick up a main relay and see if that helps. Still looking for some other ideas though.

 

[Supra Blues]

I don't think you can adjust the idle on these cars with a screw. The idle is computer controlled.

You're gonna have to check for any vacuum leaks, and run some tests on the ISC to verify that it is working properly.

I once had my ISC unplugged and it would surge at idle between 1500 and 2000.

 

[JustAnotherVictim]

I did check the isc valve it is working, the last one I had got stuck in open position like I said. You can adjust the idle there is a screw in the throttle body that increases and decreases idling rpm, trust me it's there.

 

[billspreston01]

the screw was only on 86.5-89.5 if i'm correct, and some say it's not supposed to be used to change the idle since the idle should be computer controlled. "fix the problem not the symptom" vacuum leak?

 

[Cz.]

As I remember, that screw is tuned at the factory and isn't supposed to be messed with. If you idle is off then it's probably vacuum.

 

[JustAnotherVictim]

Well I had one of my friends come over and tried his ECU to troubleshoot some more and it worked great after he hooked it up so the ECU was out on mine. I already knew I didn't have any vacuum leaks, but thanks for the responses guys

 

[MDCmotorsports]

You can change the idle with the screw, its just that (IIRC) it throws off the values to the TPS.

A high idle could possibly be a vacuum leak, but Im thinkin it might be a unpluged water sensor or a fubar water sensor causing the car to be stuck in warm up mode.

Also check to make sure the linkage to the throttle body is not bent or tweaked.

Feel free to correct me if Im wrong.

 

[shaeff]

I don't think you can adjust the idle on these cars with a screw. The idle is computer controlled.

you sir, are correct. no matter what you do to that idle screw, the ECU will still control what the idle is doing. on late model cars, the idle screw is still there, its just capped off so people cant screw around with it.

-shaeff

 

[mrnickleye]

When ever I had my battery disconnected (over the years) the ecu had to re-learn things, and the idle would vary and sometimes die. After a couple of days, it would be fine.

 

[JustAnotherVictim]

you sir, are correct. no matter what you do to that idle screw, the ECU will still control what the idle is doing. on late model cars, the idle screw is still there, its just capped off so people cant screw around with it.

-shaeff

Are you thinking GE or GTE cuz It will stay pretty constant if I change it.

 

[shaeff]

Are you thinking GE or GTE cuz It will stay pretty constant if I change it.

on both the GE and GTE. they are both controlled by the ECU. adjusting that screw will just make the computer compensate for how much you moved it, essentially putting you right back to square one.

When ever I had my battery disconnected (over the years) the ecu had to re-learn things, and the idle would vary and sometimes die. After a couple of days, it would be fine.

it shouldnt take a few days. go out and romp on it for a bit. it should take about 10 minutes... i've never had a problem. after i work on it, i take it out and go easy to make sure everything's ok, then romp on it. that should be plenty of learning for the ECU.

-shaeff