1999 Rav 4 Low Idle

[movieprops]

I just purchased a 1999 Rav 4. When I start it up ,the idle stays low, and when I turn on the A/C , the idle dosn't increase either. I know there is a sensor that is suppose to kick up the idle when the car is cold, and a sensor to kick up the A/C when it is turned on. But I don't know which sensor, or where it is located. If somebody has the answer can you help me out with this? Thanks

[anchorman]

I just purchased a 1999 Rav 4. When I start it up ,the idle stays low, and when I turn on the A/C , the idle dosn't increase either. I know there is a sensor that is suppose to kick up the idle when the car is cold, and a sensor to kick up the A/C when it is turned on. But I don't know which sensor, or where it is located. If somebody has the answer can you help me out with this? Thanks

Hi and welcome to the club.

To my knowledge the "idle up" feature is a function of the ECU and it relies on inputs from various sensors - power steering, heated rear window and those functions that you mentioned. It surprises me that you have 2 inputs that are malfunctioning so can I suggest that you try the following;

With the engine idling and warm, ease the steering either way from the rested position and see if the P/S pressure sensor picks up the idle. If the idle does not pick up then I would say that the fault is more likely to be in the ECU as three failed inputs are highly unlikely. I believe that the ECU only signals the fuel injection to respond with idle speed so there should be nothing else in the chain.

In this case I would clean the plug on the ECU or give it a squirt of WD40 or similar. I don't know where the ECU is on a 4.1 but I suspect that there may be someone watching here that does.

If it turns out that the idle does pick up with the steering, then it is 2 inputs. You should be able to see the pressure switch in the AC pipes and the one for cold running is screwed into the head or inlet manifold somewhere.

Can you help Bob?

If not I know that Haynes do a manual for it.

Good luck.