1980s ECM rebuild or replacement - 1981 Fleetwood V-8-6-4

[chrisbutnut]

I need to look in the service manual to find the instructions for adjusting the idle speed and timing.  My mechanic said he checked the timing and it was accurate.  I doubt he messed with the computer, but obviously I want it to run correctly.  Do you think having a replacement TPS on hand would be a good idea?

[TJ Hopland]

I don't remember TPS's really having problems.   People often blamed them and used them in the 'parts cannons' but I don't think they were often the cause of problems.  That being first gen DEFI and now 45 years old?  But I also would not trust old stock for sure either so I think I would wait to order one unless you happen to have found one super cheap.

[Eric DeVirgilis CLC# 8621]

I doubt the TPS is at fault unless running irregularly. TPSs often failed due to pressure washing engines. Symptoms included idling too high, too low, stalling, irregular acceleration etc.

[TJ Hopland]

Thinking about it I forgot Cadillac used that little motor dodad for idle speed that acts as the throttle stop.  Other than I'm sure not being a high end part full of precision metal components I also seem to recall that part if its operation is a switch contact so when the throttle arm hits the plunger it knows it should have control and can move it.   I remember that switch aspect being a problem with these.  Computer would extend it waiting to 'catch' the throttle where it could then retract down to the desired idle speed.  If that contact (which was internal to the assembly) was flaky it thought the throttle was further open and didn't try to adjust it.   

[chrisbutnut]

Thinking about it I forgot Cadillac used that little motor dodad for idle speed that acts as the throttle stop.  Other than I'm sure not being a high end part full of precision metal components I also seem to recall that part if its operation is a switch contact so when the throttle arm hits the plunger it knows it should have control and can move it.   I remember that switch aspect being a problem with these.  Computer would extend it waiting to 'catch' the throttle where it could then retract down to the desired idle speed.  If that contact (which was internal to the assembly) was flaky it thought the throttle was further open and didn't try to adjust it.   

Do you happen to know what the part name is for the doodad that you're referring to?

[Eric DeVirgilis CLC# 8621]

The idle control motor is separate from the TPS. I never had one that failed.

[tcom2027]

Try Module Master Moscow Id. (208) 892-0764

The rebuilt the ECM and TCM modules for my '01 Deville.