idle stablizer valve

[ch944]

As I posted before my 86 944n/a won't start when the weather dips into the 20's & 30's. Everything tests out fine and the car runs excellent when it does start. However my Haynes shows a resistance test for the cold start valve (idle stablizer) and it only has a 2 wire connection. My valve has a 3 wire connection. Does anybody know the test procedure for this? On the engine harness I have power in the center term. with the key on. If this valve where bad would it effect the performance of the car in any temp? Any input would be of help!

CH

[drew1]

CH,

According to sheet 8 of 86 944 wiring diagram, it looks like the BL/RT wire on terminal 3 of the switch comes from terminal 87 on the DME relay so is hot when the motor is running or cranking. This is common to two coils. One of the coils, terminal 1 (SW/RT wire) goes to terminal 34 on DME. the other, terminal 3 (SW/WS wire) goes to terminal 33 on the DME. Probably terminal 1 to terminal 2 should ohm the same as terminal 3 to terminal two when the wires are disconnected. One coil must open and the other close. The DME must ground whatever terminal it thinks it needs to to get the valve in the right position. That means that when it is cold there you should be able to measure a voltage difference betweeen the hot terminal and one of the others as the DME tries to open the valve and a voltage difference between the hot terminal and the other as the DME is telling it to close.

drew1

[This message has been edited by drew1 (edited 12-03-2000).]

[ch944]

Thanks drew1, sounds logical but I only have the resistance value for the 2 wire valve. Not sure if the resistance value would apply to the 3 wire valve. Will check resistance on it anyhow. I was told that dirty speed sensors will prevent the engine from firing in cold weather. will post that ? and see what happens.

CH