1995 Chevy Suburban Running rough only when at Operating Temperature

1995

Chevy

Suburban

K-1500

4X4

5.7L

Automatic





The truck works fine when it is cold and cool, but as it heats up the drivability gets worse. It feels like it is missing when it is cruising at constant speeds, but when I accelerate or decellarate it works pretty well.

When you punch the gas the bottom does not drop out. It does pick up and go.



Here is what I have looked at or changed:



1. Re-gapped plugs and looked for fouled plugs ? No fouling

2. Changed Plug Wires

3. Checked and cleaned cap and rotor ? did not change

4. Changed Coil ? Old tested bad after it heated up

5. Changed Fuel Filter 2 times

6. Dropped Gas tank and Cleaned out tank

7. Changed Fuel Pump and Sock

8. Changed Ignition Module

9. Used a timing light and watched the injectors spray out a good clean cone.

10. Changed Coolant Temperature Sensor on Intake (not the one on the block)

11. Tested Temperature Sensor on Block (Seems to be functioning properly)

12. Changed O2 Sensor (just before the cat)

13. Changed EGR Valve





This does not say that I did not misdiagnose or change out a part with a faulty part.



I am at a loss and about to break down and go to a shop.