Cadillac Owners Forum banner

1 - 3 of 3 Posts

·
Registered
(2)1984 Eldorado convertibles
Joined
·
106 Posts
Discussion Starter #1
I have an 84'Biarritz convertible, I started the car and am in the middle of getting it ready for summer. I notice now that when I start instead of the idle being high ( I then kick the gas pedal after a few minutes and the car idles normally) i need to keep my foot on the gas or the car stalls. After the car is warm the idle is very low, so I checked the codes and got

23- EST BYASS CIRCUIT PROBLEM

27 - OPEN THROTTLE SWITCH CIRCUIT

NOW, IF I HAVE TO REPLACE THE THROTTLE SWITCH I SEE VARIOUS PRICES FROM 21.00 TO 95.00 ( WHICH DO I CHOOSE)

ALSO WILL REPLACING THE SWITCH HAVE THE CAR IDLE HIGH WHEN COLD AND ALLOW ME TO KICK DOWN AFTER A FEW MINUTES?

ANYONE?

RD
 

·
Super Moderator
White Diamond '03 DHS (with DTS floor shift)
Joined
·
86,793 Posts
If I remember correctly, OPEN throttle switch tells the ISC motor that your foot is on the throttle, thus not in idle mode and the ISC motor retracts the plunger. If you ARE at idle under that condition, your idle will be low.

Not sure what to tell you on choices. See what others say.
 

·
Registered
1926 Model T street rod, 2000 Jaguar XJ8, 1999 Corvette.
Joined
·
6,737 Posts
First, pumping the throttle has nothing to do with lowering the idle on this car. The idle control motor (ISC) simply retracts as the car warms up. You need a friend to start this car cold with you looking over the drivers fender (air cleaner off) to verify the idle motor shaft extends as he rotates the key to the start position. Quite frankly, this idle motor shaft should extend slightly any time the car is started hot or cold. With the car off, open the throttle by hand and verify that's there some play in the shaft on the idle motor. It should loosely move in/out about an 1/8 of an inch. If no play, then the idle motor is shorted internally. Had that happen on a buddies car and the cause was the idle motor's wire harness was pinched (shorted) under an A/C compressor rear bracket! If you verify you need a new idle control motor, then you must adjust it after installation. Do a search if necessary, on ISC and TPS adjustment.
 
1 - 3 of 3 Posts
Top