idle issue. I'm clueless video attached

[queenskid926]

Ive done so many 7m non turbo to turbo swaps and this by far has had the most issues that I've ever came across

Here is the current issues:
Sometimes the car is hard to start (10+ seconds of cranking), sometimes its not
As soon as the car is started, cold start or when its warm, It jumps up to 2500 rpm and stays there.

Now it has done this before, and I thought that it was a faulty iscv. The gasket for it was cracked and leaking so i put some fipg on it and instant 1200 rpm idle.
Then turn the car off and back on rose up to 2500 again.

I installed another iscv that i bought from tubbie and instant 1500 cold start then 1000 idle when warm. Then the next time started up again it jumped back to 2500.

The idle does drop down when i squeeze the vaccum hose for the iscv.

Now the wierd part is this, Nothing has any affect on the idle. I unplugged the tps, afm, iscv plug and it stays at 2500 rpm. When i unplug the iscv vacuum hose from the accordian hose, the car still runs? it struggles and the idle speed does drop but it still runs.

What to do guys i was suppose to take the car to get my exhaust done so i can finlly drive it back on the rd then this issue that i thought was fixed popped backed up.



here is a video that shows cold startup and how it jumpes to 2500. and what happens when i unplugg the various connectors starting with the tps then the afm and then the iscv vaccum hose at the accordian pipe. and what happen when i try and block off the vaccum.

http://www.youtube.com/watch?v=uWs3S3I3x24

oh yea its open downpipe and its freezing out side here in nyc so my video is a lil rushed and i didnt want my neighbors to start complaining about the noise.

2moro i have no skool and off from work and will have all day devoted to fixing this issue.

Sorry for the grammars this is a lil rushed

 

[87n/a_supra]

ok i am officially clueless on what that could be, i sent the link to a couple of friends of mine to see what they think.

 

[JonoTurbo]

Is your throttle stop adjusted correctly - by that I mean does the throttle valve close all the way when you aren't pressing on the gas pedal?

It sounds like you simply have too much air flowing into the engine. It is being metered by the AFM, so the car isn't running like crap, so somewhere after the AFM there is a leak causing too much air to bypass the throttle body. This could be caused by a faulty ISC, or simply an incorrectly adjusted throttle stop or idle set screw.

 

[queenskid926]

ok i am officially clueless on what that could be, i sent the link to a couple of friends of mine to see what they think.

thanks bro i appreciate your response and ur help so far.

Like i said guys i have all day 2moro to work on her, I just don't know where to start and do not wanna dish out money replacing parts to just cancel it out. Pockets are close to being empty right now as with any supra owner.

 

[queenskid926]

Is your throttle stop adjusted correctly - by that I mean does the throttle valve close all the way when you aren't pressing on the gas pedal?

It sounds like you simply have too much air flowing into the engine. It is being metered by the AFM, so the car isn't running like crap, so somewhere after the AFM there is a leak causing too much air to bypass the throttle body. This could be caused by a faulty ISC, or simply an incorrectly adjusted throttle stop or idle set screw.

throttle body is fully closed. iirc if it was open and the afm unplugged it would bog down, I know on other supras i worked on if the afm is unplugged it idles around 1000 and runs rich as hell, and give it any gas it would bog down. this didnt do that . U can hear it when i unplug and plug the afm back in but it didnt do anything to the idle.

 

[87n/a_supra]

i agree with jono. i was just going to say something like check the throttle adjustment.

 

[queenskid926]

so its getting measured air so back to the iscv? I mean i changed the idle speed valve be4 as stated in post 1 and the idle was at 1200 but then rose back to wat it is now randomly? so both are bad? again there is no change when i unplug the afm. This is just wierd.

 

[87n/a_supra]

it is kinda weird lol. take and go check the ICV, it may be stuck. its a long shot but im almost outa ideas. another idea i have is that this may be an issue concerning your code 11.check all that and let us know.

 

[87n/a_supra]

sorry my bad i forgot you said you replaced that already

 

[87n/a_supra]

check the vacuum setup

 

[87n/a_supra]

ok it just accured to me that you are running an 87 harness and an 89+ throttle body.now on an 87-88 the idle speed is controlled by an idle set screw on the throttle body.on the 89+ cars the idle speed is controled by the ECU. nor what you need to do is find an 87-88 throttle body and put it on there. i may have one laying around some place here. ill let you know if i find it.and ill ask my buddy JONO if he knows a way you can do it by just rewireing the harness for that throttle body. ut i think it will be easier to just switch throttle bodies.

 

[jetjock]

i work at a dealership as a technitian.....

I understand you being whatever that is above but several of your posts, including that last one, contain misinformation. This being the Tech Section I suggest in the future you check your facts before posting...

 

[queenskid926]

ok it just accured to me that you are running an 87 harness and an 89+ throttle body.now on an 87-88 the idle speed is controlled by an idle set screw on the throttle body.on the 89+ cars the idle speed is controlled by the ECU. nor what you need to do is find an 87-88 throttle body and put it on there. i may have one laying around some place here. ill let you know if i find it.and ill ask my buddy JONO if he knows a way you can do it by just rewiring the harness for that throttle body. ut i think it will be easier to just switch throttle bodies.

ok the throttle body makes sense, before a jdm 89 throttle body was on which still did not have an idle speed screw.

This is a jdm motor so there is no egr equipment or charcoal canister.

let me know if you find that 87 throttle body. i have a bare one with no linkage or tps that i may just use the tps from the 89 one and assmeblle together to check it. I think i had a 89 throttle body on my old 87 and it ran fine with no issues? but its worth a shot.

any other ideas guys?

Im try checking this new iscv again and see if its within tsrm. I mean i just got it like 2 days ago and for both of them to fail and do the same exact thing would be crazy

 

[7thousandpiecesMGTE]

ok it just accured to me that you are running an 87 harness and an 89+ throttle body.now on an 87-88 the idle speed is controlled by an idle set screw on the throttle body.on the 89+ cars the idle speed is controled by the ECU. nor what you need to do is find an 87-88 throttle body and put it on there. i may have one laying around some place here. ill let you know if i find it.and ill ask my buddy JONO if he knows a way you can do it by just rewireing the harness for that throttle body. ut i think it will be easier to just switch throttle bodies.

This is incorrect. On 87-88 the screw is set closed from the factory on the throttle body, Idle is still controlled by the ECU and ISCV. I recently learned this because mine was adjusted open and when I closed it the car would not start and idle on its own. Further inspection revealed a faulty ISCV, clogged check valve and gunked up throttle body, so basically the motor couldn't breathe at idle.

If opening this screw on the throttle body allows your motor to run better you have a problem somewhere. Messing with the screw only partially hides the issue.

Edit: Jet jock FTW

 

[queenskid926]

This is incorrect. On 87-88 the screw is set closed from the factory on the throttle body, Idle is still controlled by the ECU and ISCV. I recently learned this because mine was adjusted open and when I closed it the car would not start and idle on its own. Further inspection revealed a faulty ISCV, clogged check valve and gunked up throttle body, so basically the motor couldn't breathe at idle.

If opening this screw on the throttle body allows your motor to run better you have a problem somewhere. Messing with the screw only partially hides the issue.

Edit: Jet jock FTW

yea i coulda sworn ii had an 89 throttle body on my old 87 and it ran fine. Also it seems that the only way the 87 throttle body would have helped me if my car seemed like it was dying and i open toe screw to raise the idle so it can idle better. My issues is that its idling way to high, air is getting by somewhere and its metered air.

 

[queenskid926]

ok lets star with everything that controlls the idle,

iscv,
if the throttle body is completely shut
ecu

 

[7thousandpiecesMGTE]

check for vacum leaks (not just a visual check, this can deceive you)

 

[87n/a_supra]

ok that is information coming straight from all data but it has been known to be wrong before. if anyone has any more ideas go ahead, cuz im out of ideas, that was my last one so im out.

 

[87n/a_supra]

i still think it has something to do with your code 11

 

[queenskid926]

Ill check for codes and see if it comes up again this code just comes and goes when it wants too. I wonder if its just from the battery + terminal not being on tight to cause it throw the code? i just it on to turn the car on then wen im done for the day i turn it off. to save my battery.