ISC Idle Speed Control
 

Hi

I've a problem with my cadillac deville 1981!

when i start the car (it starts hard) the idle gas is very high, and when i put a gear (D) in the "check engine" light flashes and the ECM tells E30 -- idle speed control curcuit!

i did the ECM check (output cycling test):
start the car
turn off
within 2 seconds turn ignition on
go to diagnostic mode
when 70 is displayed press instant average
then press accerlator pedal (the throttle switch open)
release the pedal
turn cruise control on (something happens if i let it turned off)

now the ISC-motor should move
i think this motor is there where, the accerlator-cable comes under the air filter. this motor klicks and goes in and out but more in than out!

and if i turn curise control on, something else makes a noise i don't know what it is!

can anybody help me??

regards Adrian12

RE: ISC Idle Speed Control
 

Hey Adrian: Possible fast idle problems:Throttle position switch is in need of adjustment,poor connection at the fast idle valve,or open circuit in the heating element, or a vacuum leak around the throttle body. When you go to start the car does the gas peddle ratchet (shake) as you turn the ignition on??? This would be the ISC adjustment.

RE: ISC Idle Speed Control
 

sometimes it shakes, but not on every ignition!

can you explain me how to check the TPS and how to adjust it?i don't think that all other things are the reason!

thanks

RE: ISC Idle Speed Control
 

Hey Adrian: Maybe you could help me with something. In my trouble code list there is no mention of code 18 or 38 but it came up on the readout. Do you have a code sheet with these numbers on it and what do they mean.

RE: ISC Idle Speed Control
 

you have PM ;)