Idle throttle body

[alltheway2drag]

Hi , after my idle problems ive started trying to solve that out.
First thing ive donne is change the throttle body and the gaskets. The the IAC,TPS

(look at picture)

http://www.google.ca/imgres?q=throt...16&ved=1t:429,r:2,s:29,i:140&biw=1024&bih=671

top left of the throttle hole (plate) there is a wire pluged in.
Mine is broken , and if i let that plugged in on my car , with my new throttle body and other stuff. My idle jumps alone.

Please help

 

[eagle93tsi]

The switch on the upper left is the throttle closed switch. With this disconnected the computer does not know the throttle is closed and will kick up the idle.

Fix the wiring and reconnect the switch as this should help. If not the switch may need to be checked for proper operation and setting. There is a simple procedure in the service manual.

Also you may want to read through this great FAQ on idle issues for other ideas to look at.

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

 

[steve]

The switch on the upper left is the throttle closed switch. With this disconnected the computer does not know the throttle is closed and will kick up the idle

Your correct that if the idle position switch is disconnected the ECU won't know that the throttle is closed but it doesn't kick up the idle.

It doesn't do anything to try and control the idle speed, if the engine is getting too much air bypassing the throttle plate when it's closed it will "idle" high. When the switch is connected the ECU is recognize that the idle is too high, try to lower it, and if that fails turn off the injectors until the RPMs drop, causing idle surge.

 

[alltheway2drag]

Cool thankx guys .. well the male and femal of this wire is broken .. only wires left ,, and when i plug the wires on the little bit of metal left on the top left .. my idle jumps. So im keeping that unpluged for now.

 

[chadillac2820]

I think what Steve is suggesting is that you have a vacuum leak and i agree.

Or a bad iac

 

[alltheway2drag]

i have changed de IAC and i have no vacuum leak , the only thing im missing is the thermostat valve (2 vacuum plugs there) , so i have blocked those 2 vacuum.
Note (the thermo vavle) is a full bolt , wich means no air passes that .. so blocking the 2 vacuum is supose to be ok. Ive blocked them at the end of the vacuum line.

steve what do you mean tring to lower the idle ? (i cant turn the idle screw its like to dusty and imposible to get the dust out of the hole.

And what do you mean by closing the injectors ? how do i do that .. thank you

 

[steve]

i have changed de IAC and i have no vacuum leak , the only thing im missing is the thermostat valve (2 vacuum plugs there) , so i have blocked those 2 vacuum.

Note (the thermo vavle) is a full bolt , wich means no air passes that .. so blocking the 2 vacuum is supose to be ok. Ive blocked them at the end of the vacuum line.

steve what do you mean tring to lower the idle ? (i cant turn the idle screw its like to dusty and imposible to get the dust out of the hole.

And what do you mean by closing the injectors ? how do i do that .. thank you

1) Why did you change the ISC? If it was because one of more of the coils was bad then you need to make sure that the drivers for the ISC in the ECU haven't been damaged.

2) How do you know you don't have any vacuum leaks?

3) The ThermoValve is for the EGR. It controls when vacuum can be applied to the EGR valve to open it allowing exhaust gases to be mixed with the intake air. The EGR valve is one of the things that can leak.

4) The BISS (Basic Idle Speed Screw) is one of several throttle plate (butterfly) bypasses. The other major two are the ISC (Idle Speed Control solenoid) and the FIAV (Fast Idle Air Valve).

The adjustment procedure for the BISS requires you to make sure the car is at operating temp, so that the FIAV is closed. Ground the timing check connector and the DLC mode pin to put the ECU into adjust BISS mode and lock the ISC at it's default position. And it requires the IPS to be grounding the signal from the ECU telling it that the throttle is closed. Then you can turn the BISS in or out to lower or raise the idle speed to it's factory setting.

If you can't turn your BISS screw you need to fix that.

5) The IPS (Idle Position Switch) performs two functions. It grounds a signal from the ECU to tell it when the throttle butterfly is closed and serves as the stop for the butterfly. When you replace yours you'll need to make sure it's not holding the butterfly open.

6) What I said was if the ECU sees that the engine is running faster than it should with the throttle closed, it shuts off the injectors until the idle speed drops and then turns than back on. Normally this is done while your decelerating to save fuel but at idle it causes what we know as idle surging.