How to adjust the early c4 TPS and idle speed?

This tech paper will discuss the procedure for correct adjustment of the Minimum Idle Speed and for adjustment of the Throttle Position Switch (TPS) on the early C4 Corvette TPI systems. These steps apply specifically to the 1985 model year, and in general to

Can a bad throttle position sensor cause idle surging?

Idle surging can be caused due to other issues in the car, but if it happens in conjunction with other throttle position sensor symptoms, the culprit is often the TPS. At idle, the ECM will not get the correct information and the throttle will variate randomly causing idle surges. 3) Check Engine Light

What happens if you set the TPS too far out?

Setting the transition too far out, would result in a sluggish throttle response, since the ECU would see a longer idle section on the TPS. If your TPS makes the idle transition (below 2300 to infinite) but it will do it at 0.90mm instead of at 0.85mm does this mean the TPS is bad?

When to remove the TPS on a throttle?

When doing this, it is important that the TPS should be removed to prevent contamination (a primary cause for failure) and the throttle body-to-plenum gasket replaced. We strongly recommend cleaning your throttle body thoroughly before attempting any adjustment.

What are the symptoms of a bad TPS?

Below are common symptoms of a faulty TPS. In most of the cases, all of these symptoms will show together making it easier to detect the faulty component. Jerking or bucking of the vehicle is the most common symptom of a bad TPS.

What causes idle surges on a car ECM?

Can a bad check engine light be a bad TPS?

The check engine light will randomly turn on and off even if the car is running smoothly without any jerks and stalling. This is often the first ever symptom of a bad TPS. Using a code reader, you should be able to confirm whether a faulty TPS is the culprit or a different component.

How to adjust the early c4 TPS and idle speed?