i have had no problems untill like 2 days ago when i would first start up it would go to 1300 and would warm up and go back to normal.tonight it was just staying at 1300 and wouldn't go down.does anyone know what the problem could be?:1zhelp:
idle problem
- Thread starter boostinsupragirl
- Start date
annoyingrob said:
agreed, and also if I remember correctly if your pulling an error code of 51 it doesn't actually throw a light but if you check your codes it will be there IF it is TPS related.
now its up to almost 2 grand.i got to get this fixed its burning up all my gas lol. how much does the tps run?
High idle can have one (or more) causes. Check for codes 1st...some do not illuminate the check engine light.
- Check for vacuum leaks and air leaks in the accordion hose.
- Check that the throttle body plate physically closes all the way...that there's no build-up stopping it from closing around the edges. Check the linkage for free movement and good spring tension to close the throttle body plate.
- Cold start injector opens and supplies starting fuel to the intake manifold based on the Cold Start Injector Time (CSIT) switch and coolant temperature. It shuts the CSI off after a set time. The CSIT is located on the top of the water neck (pointing straight up) behind the thermostat housing. The CSI is located on the bottom of the intake manifold in the center. To check, unplug the CSIT with the engine warm. If that helps, it's the switch...if not, unplug the CSI itself. If that helps, it's the CSI itself or the wiring between the CSIT and the injector. The injector solenoid could (not likely) could be stuck open as well. The CSIT or injector does not generate a code.
Here's how to test the CSIT switch:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=112
Here's how to test the injector:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=79
- The TPS must send an IDL signal to the ECU to enable idle speed control mode. Should generate a code 51...the TPS could be bad or needs adjustment. Read this:
http://www.mkiiitech.com/forums/viewtopic.php?t=912
How to test/adjust the TPS:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=101
- The ISC valve could be staying open...it does not generate a code. Normally, the ISC goes full open when the engine shuts down. After start, the ISC steps closed on ECU command based on coolant temp and ECU learned value. To check this, remove the ISC on a cold engine, IGN off to see if it's full open. Replace the ISC and warm up the motor. Unplug the ISC and shut the engine off. Remove the ISC and check the valve to see if it closed. This is a great time to clean the ISC valve w/ brake cleaner and take a look at the check valve under the ISC in the intake manifold flange. A clogged check valve can also cause idle problems (usually low idle or rough idle though).
TRSM test procedure on the ISCV:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=106
- The ECU water temperature sensor could be bad, but it shouldn't cause such a high idle. Should generate a code 22. To test, here's the page from the TRSM:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=113
Here's a pic of it's location:
- Check for vacuum leaks and air leaks in the accordion hose.
- Check that the throttle body plate physically closes all the way...that there's no build-up stopping it from closing around the edges. Check the linkage for free movement and good spring tension to close the throttle body plate.
- Cold start injector opens and supplies starting fuel to the intake manifold based on the Cold Start Injector Time (CSIT) switch and coolant temperature. It shuts the CSI off after a set time. The CSIT is located on the top of the water neck (pointing straight up) behind the thermostat housing. The CSI is located on the bottom of the intake manifold in the center. To check, unplug the CSIT with the engine warm. If that helps, it's the switch...if not, unplug the CSI itself. If that helps, it's the CSI itself or the wiring between the CSIT and the injector. The injector solenoid could (not likely) could be stuck open as well. The CSIT or injector does not generate a code.
Here's how to test the CSIT switch:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=112
Here's how to test the injector:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=79
- The TPS must send an IDL signal to the ECU to enable idle speed control mode. Should generate a code 51...the TPS could be bad or needs adjustment. Read this:
http://www.mkiiitech.com/forums/viewtopic.php?t=912
How to test/adjust the TPS:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=101
- The ISC valve could be staying open...it does not generate a code. Normally, the ISC goes full open when the engine shuts down. After start, the ISC steps closed on ECU command based on coolant temp and ECU learned value. To check this, remove the ISC on a cold engine, IGN off to see if it's full open. Replace the ISC and warm up the motor. Unplug the ISC and shut the engine off. Remove the ISC and check the valve to see if it closed. This is a great time to clean the ISC valve w/ brake cleaner and take a look at the check valve under the ISC in the intake manifold flange. A clogged check valve can also cause idle problems (usually low idle or rough idle though).
TRSM test procedure on the ISCV:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=106
- The ECU water temperature sensor could be bad, but it shouldn't cause such a high idle. Should generate a code 22. To test, here's the page from the TRSM:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=113
Here's a pic of it's location:
Thanks Clip...a little follow up on this:
The CSIT and the injector both receive power (+12V) from the same source as the starter. It is highly unlikely the CSI will function electrically once the car is started...there would have to be a short providing +12V to the injector. The only other way the injector could be providing fuel to the intake after start, is if it is leaking or the solenoid is stuck open.
The CSIT and the injector both receive power (+12V) from the same source as the starter. It is highly unlikely the CSI will function electrically once the car is started...there would have to be a short providing +12V to the injector. The only other way the injector could be providing fuel to the intake after start, is if it is leaking or the solenoid is stuck open.
well i just bought a coolent temp senser so i will put that in, and i fixed and re wired my radator senser.TPS was alittle on the pricey side i will have to wait on that and the store didn't know what a cold start injector is,do you know where i can get that?
You could save yourself considerable time and money by testing those things rather then replacing them. Easy to do and you'll learn something. The less shotgunning of parts, jiggling of wires, or dancing around the car chanting while waving a bag of chicken bones and eye of newt the better off you'll be.
jetjock said:
aww, but that last part is rather fun...
(semi-worthless post, I know... anything I have to add would only be repeating what jdub said.. lol)
not to jack a thread.... in the above posted pic, what is the BVSV?
mine has been broken for along time lol, the 2nd hose coming out of the bvsv doesnt connect. the piece broke off some how, never had any problems so i didnt care. i always figured it was an emissions thing?
mine has been broken for along time lol, the 2nd hose coming out of the bvsv doesnt connect. the piece broke off some how, never had any problems so i didnt care. i always figured it was an emissions thing?
I'm with JJ...I'm betting on a vac or air leak. Could also be the throttle body not closing as previously posted....check the simple things first. I'd focus on the ISC next too.
Like I said...it's very unlikely it's the cold start injector because of the way it gets power.
To check codes:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=23
Unless you have a supra monitor, there is no "scanner" I know of for this car
And throwing parts at the problem will get pretty expensive fast.
Like I said...it's very unlikely it's the cold start injector because of the way it gets power.
To check codes:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=23
Unless you have a supra monitor, there is no "scanner" I know of for this car
And throwing parts at the problem will get pretty expensive fast.
iwannadie said:
It is an emissions thing. Just because you've "never had any problems" you could feel by leaving it open doesn't mean bad things aren't happening to the EFI system. I'd explain it to you but since you're so intent on crapping up the air I'm breathing I'll let someone else have that honor.
jetjock said:
lol, man i didnt know spitting a little coolant emissions would hurt someone so bad. i guess everyone on this forum with straight exhausts, test pipes, charcoal cans removed ect are all ok?
i want to fix it, just never knew what it was or how important it was. having money to fix something thats not keeping the car from running is low on my lists, sorry.
knowing what it is and how important it is to have fixxed would certainly motivate me. also knowing how much the part would cost might make me run out today and do my part to clean air.
the P/O of this car kinda f00ked it up a bit. there is a whole lot of electrical tape around one of the BPV hoses, and i can see more of the wires than ide want to. we went over the vac hoses (the ones we could see) and made sure that they were going where they needed to. we also umplugged and replugged some connections (including ISC) and it seems to idle right around 600-800 RPM. BTW, no codes came up.
about the whole scanner thing. something that plugged in the DIAG port read that there were no codes being thrown.
about the whole scanner thing. something that plugged in the DIAG port read that there were no codes being thrown.