[goldenballs]

My 97 2.3 9000 Turbo has developed a problem, the Tickover rises to 1500 rpm then settles again. You can also feel this as a surge when driving at low speeds. I checked the usual for air leaks etc then noticed this happens only when the AC compressor engages loading extra torque on the motor. There must be a sensor or valve not compensating correctly... any ideas appreciated.

Nidge

 

[goldenballs]

UPDATE: Ive just realised the CHECK ENGINE warning is lit up... guess its a trip to the dealers unless anyone has any ideas

 

[StephenA]

Nidge

Have you disconnected the battery to reset the ECU?

The check engine light might be on for various reasons (it flashes codes at you). But I am not sure if the flash codes for the 97 are available (if they are then they are on this site somewhere).

It sounds like the A/C kicks in, the revs drop and the idle control valve opens up too far. It might be worth cleaning it.

Steve

 

[goldenballs]

Steve

Thanks for the reply, the Check Engine light has now gone out but as you say it does seam to be flashing in a sequence once the ignition is on before it clears.

Where is the idle control valve located? I was told to check this by the dealer but dont have a manual yet!!

Nidge

 

[9000CS23T]

Have you checked if the AC compressor is turning freely? We had a car in the other week and it was really dragging the engine down when the comp cut in. When I checked the compressor with the engine off, I could hardly turn it - it was starting to seize.

 

[goldenballs]

Due to the fact the Tickover recovers I would think it is free, just the initial pull on the motor that is upsetting the tickover.

Forgive my ignorance with AC Compressors here, but the belt is turning a pully, I then hear the solenoid engage the "outer Pully" which then spins, this is when the revs rise. With the ACC selected to Auto the compressor is not engaged all of the time.... is that correct?,

 

[mark e]

The compressor cycles on and off according to the cooling duty required. The fact that the check engine light is flashing means that there is still a fault that needs to be investigated. It might be caused by an AIC valve problem (which is located underneath the throttle body BTW. It's easier to get at if you remove the reducing rubber elbow between the throttle body and intake delivery pipe).

Flash codes are listed here.