hotrodmerc
New Member
Just the other my wife noticed the idle speed was about 1800 rpm. I scanned the car and got a code 122, 124, 332 in the memory codes. It sounds like the TPS needs replaced, but i'm not sure. Any ideas?
High idle speed
- Thread starter hotrodmerc
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stevetatro
New Member
There's an easy way to test the TPS. I'm sure it's been documented on this forum many times, so you could try the search feature for more info.
Basically you backprobe the middle TPS sensor plug wire with one lead of a multimeter. The other lead goes to any ground. Turn the key on (no need to start the car) and the voltage should be just below 1.0 VDC (people usually strive for 0.96). While the multimeter is still connected, slowly open the throttle (you can obviously use the paddle on the throttle body). The VDC should slowly rise, without interruption, linearly with the throttle. At wide open throttle (WOT) the volts should be around 4.5, definitely not over 5.0.
If you sense any 'dead' spots in the voltage readings, like all of a sudden it drops as you open the throttle, your TPS is bad. Also if it reads over 5.0 at WOT you should replace the TPS.
AutoZone (and other fine automotive parts stores) sell Wells brand sensors, including the TPS, which work just fine for around $20.
Good luck.
Basically you backprobe the middle TPS sensor plug wire with one lead of a multimeter. The other lead goes to any ground. Turn the key on (no need to start the car) and the voltage should be just below 1.0 VDC (people usually strive for 0.96). While the multimeter is still connected, slowly open the throttle (you can obviously use the paddle on the throttle body). The VDC should slowly rise, without interruption, linearly with the throttle. At wide open throttle (WOT) the volts should be around 4.5, definitely not over 5.0.
If you sense any 'dead' spots in the voltage readings, like all of a sudden it drops as you open the throttle, your TPS is bad. Also if it reads over 5.0 at WOT you should replace the TPS.
AutoZone (and other fine automotive parts stores) sell Wells brand sensors, including the TPS, which work just fine for around $20.
Good luck.
hotrodmerc
New Member
TPS was 1.0-4.7 volts. Smooth with no jerky areas. Any ideas what is causing to make the idle run about 1800rpm????
sdpatt
Sr. SHO Engr.
A vacuum leak or a failing idle air control valve (IAC or IAB).
Cleaning the valve portion of the AIC valve will have no effect if the problem is in the electrical servo portion. That will require a replacement. This can be done with an auto parts store available IAC valve and a simple, old fashioned, L-shaped Allen wrench to access the lower bolt on the IAC valve with the intake still attached to the engine.
Cleaning the valve portion of the AIC valve will have no effect if the problem is in the electrical servo portion. That will require a replacement. This can be done with an auto parts store available IAC valve and a simple, old fashioned, L-shaped Allen wrench to access the lower bolt on the IAC valve with the intake still attached to the engine.
hotrodmerc
New Member
It doesn't give any IAC codes. I have checked for vacuum leaks and found none. I think i'll put on a new TPS anyway since it is so cheap, and try resetting the idle by disconnecting the battery cable to erase the KAM. I'll see what happens.
sdpatt
Sr. SHO Engr.
You can reset the KAM by disconnecting the ground lead to the EEC without resetting all of your radio stations, clock and climate control settings. Just follow the smaller black lead off the negative terminal until you reach the single lead connector at the passenger side fender above the winshield washer bottle. Unplug that connector to erase the KAM. Reconnect to get back to business.
Blank-Disk
Member
done any work on the car lately? When my cousin and I cleaned out my intake manifold and replaced all the bad seals, the idle speed went from about 600 RPM to about 2,100 RPM.
I honestly don't know what people are talking about with using the comptuer to reset the idle, especially if it's too high. I've always just adjusted the screw on the throttle body, reset the computer to adjust the performance accordingly, and that's that.
I honestly don't know what people are talking about with using the comptuer to reset the idle, especially if it's too high. I've always just adjusted the screw on the throttle body, reset the computer to adjust the performance accordingly, and that's that.
stevetatro
New Member
The screw is designed to be in one position - no adjustment necessary in 99.9% of all cases. I know, it seems strange that it's threaded for adjustment if no adjustment is necessary, but it's true.
The car has a computer controlled idle.
If after doing intake work the idle is messed up (2100rpms?) you probably have other problems.
Have you seen the unofficial idle set procedure? It's probably still a sticky on the main Gen1/2 maintenance page. I've also seen Scott post it many times.
EDIT: Yep, still a sticky. http://www.shoforum.com/showthread.php?t=10161
The car has a computer controlled idle.
If after doing intake work the idle is messed up (2100rpms?) you probably have other problems.
Have you seen the unofficial idle set procedure? It's probably still a sticky on the main Gen1/2 maintenance page. I've also seen Scott post it many times.
EDIT: Yep, still a sticky. http://www.shoforum.com/showthread.php?t=10161
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