WTB Lanos 1.6L DOHC Idle speed sensor

daewooluvr · Post by **daewooluvr** » Thu Jun 23, 2005 11:00 pm

That lil one that goes on the throttle body. I think mine's toast. My idle has been all over the place. The engine only has 5K miles on it. I took off the throttle body and cleaned it really good and that didnt' change anything.

Post by **PrecisionBoost** » Tue Jun 28, 2005 1:49 am

Are you talking about the "idle air control" on the throttle body?

daewooluvr · Post by **daewooluvr** » Tue Jun 28, 2005 2:03 am

yes that's the one but now I'm not sure if that's the one that needs replaced...

I disconnected the Idle Control Sensor and there was no change.

I disconnected the Throttle Positioning Sensor today and started the car and it idled perfectly.

Post by **PrecisionBoost** » Tue Jun 28, 2005 7:25 pm

I guess a bad TPS would make it idle funny... but you would think that it would make it drive poorly as well since it uses the TPS as part of the calculation for the fuel injector pulse width.

daewooluvr · Post by **daewooluvr** » Tue Jul 05, 2005 1:51 pm

yeah it drives just fine, just the idel is all over the place. Perhaps the ECU is going bad...

Post by **PrecisionBoost** » Tue Jul 12, 2005 6:09 pm

The idle air control is a valve that is controlled by a stepper motor.

The ECU sends pulses to the motor to open and close the valve in order to keep the idle nice and smooth.

If the motor in the IAC was dead the idle would be all over the place and disconnecting it would make zero difference.

If you disconnected the TPS perhaps the ECU jumps to a preprogrammed "safe" injector pulse width.

I accidentally forgot to reconnect my MAP sensor one day and the car idled just fine and drove away just fine.

When the CEL came on and I noticed it didn't have the same smooth pickup I smacked myself in the head, pulled over, shut off the engine, disconnected the battery, reconnected the MAP and let it sit there until the ECU was reset..... then it worked great.

So what I'm saying is that what you might be experiencing is a situation where the ECU ignores the MAP and TPS sensors and goes onto a default map it uses when there is a sensor failure or disconnect.

The only reason it idles so funny in the first place is because the ECU is continually adjusting the pulse width based upon data from the 02 sensor.

So....... I still think it's just a matter of replacing the IAC

daewooluvr · Post by **daewooluvr** » Wed Jul 13, 2005 1:54 am

so does anyone have any spare TBs lying around with the sensors on them. I had two of them but sold them.