1983 SDV HT4100 Idle Speed/TPS

[George Woodford clc21025]

Any advice for installing Idle Speed Control motor and Throttle Position Switch on a 1983 SDV HT4100? I am surprised that the ECUs are still available from GM.  The ECUs cost about $110 plus core.  Thanks for your advice.

[Gene Roqueplot CLC#19950]

You will need the shop manual as to set the TPS you need to have the correct parameter displayed (on the Climate Control Panel) to set the correct number.The ISC needs to have a learned idle done if i remember correctly as its been awhile! Plus you will need a jumper wire to seat the ISC motor.
Later
Gene

[George Woodford clc21025]

Resolved the problem with Idle Speed Control.  I had irregular control of the Idle Speed Control motor plunger at idle.  Replaced the ECU and the it resolved the problem.  I also replaced the Idle Speed Control motor prior as a source of the problem.

[Rusty Shepherd CLC 6397]

You probably avoided an accident or at least a scare.  When it was about two or three years old, I drove my neighbor to the airport in her 84 SDV and when I was putting it into her garage, the engine started idling too slowly and felt like it was going to stall, then sped way up with the throttle still closed before settling back to a normal idle. Fortunately, my foot was over the brake so I barely avoided running into the back of her garage. The ISC was replaced shortly thereafter.