WhalePirot
Well-known member
Get a Helm manual and reference the emissions section as well as the aforementioned underhood sticker. It will provide you the proper test/adjustment of the IAC, TPS and such. Your challenge may be to follow the steps, w/o the special tools, unless you have or make them.
Are there any codes?
The base timing, can only be set with the EST disconnected, and gives a proper start point for the ECM. Similarly, a base voltage is required for the TPS and the IAC.
Remember, the basics of the 'old' engines still apply, like vacuum leaks, good wires and plugs, valve adjustment, etc. This electronic control stuff just does a more precise job of the same old thing. BUT, good electrical connections become essential, as do the proper function of the sending units; the 'eyes and ears' of the ECM. Properly setting the adjustable sensors will deliver Corvette performance.
One of many reasons for a high idle is the ECM operating in the wrong section of the fuel tables, based upon inputs. Low vacuum (high MAP) can wrongly tell it that the throttle is open more than it is, demanding more fuel.
I use my old vacuum gauge as often as ever, BTW.
Are there any codes?
The base timing, can only be set with the EST disconnected, and gives a proper start point for the ECM. Similarly, a base voltage is required for the TPS and the IAC.
Remember, the basics of the 'old' engines still apply, like vacuum leaks, good wires and plugs, valve adjustment, etc. This electronic control stuff just does a more precise job of the same old thing. BUT, good electrical connections become essential, as do the proper function of the sending units; the 'eyes and ears' of the ECM. Properly setting the adjustable sensors will deliver Corvette performance.
One of many reasons for a high idle is the ECM operating in the wrong section of the fuel tables, based upon inputs. Low vacuum (high MAP) can wrongly tell it that the throttle is open more than it is, demanding more fuel.
I use my old vacuum gauge as often as ever, BTW.
