Chevrolet Cobalt Service & Repair Manual: Compression Pressures
| 1. |
Ensure engine is at room temperature
and battery is fully charged. |
| 2. |
Disconnect wiring from ignition module
and remove spark plugs. |
| 3. |
Throttle body valve should be wide
open. |
| 4. |
Install a suitable compression gauge
into No. 1 spark plug opening and crank engine through four compression
strokes. |
| 5. |
Lowest reading cylinder should not
be less than 70 percent of highest and no cylinder reading should
be less than 100 psi. |
| 6. |
Repeat compression test procedures
for remaining three cylinders. |
| 7. |
Remove compression gauge from engine,
then install spark plugs and engine cover. |
|
Idle speed is controlled by the
ECM/PCM. No adjustment is required.
Curb Idle Speed
Curb idle speed is controlled
by the ECM/PCM. No adjustment is required.
Fast Idl ...
Idle Speed & Mixture Adjustments