Egr Failure Demon

[Willycool]

Hello people!

I have a strange problem this time!

My buddy has an 85 c4 (nice one too), and he has been getting a code 32 (EGR) failure light.

Now...the service engine light only activates when the car is driven on the highway at a steady spped for about 20 miles. The light does not activate in city driving.

I helped him change the egr valve, heat switch, vacum switch, ecm and the vacum hoses. We tested the egr valve and wiring and everything seem fine.

Now...stange part # 2... When the outside temp is between 80 and 90 degrees...no code light (service engine soon) during highway driving.????!!!!

With an outside temp of below 80 degrees......light is activated during highway driving.????!!!!


Anyone got any ideas???

Shall i call the priest to have the demons removed?ad

If u can help us solve this problem....the drinks are on my friend Rob!!!



Thanks


Willycool

 

[trrgod]

What your friend has is a very rare optioned SUMMER ONLY (WINTER DELETE) Corvette. Only one of these was ever sold.

 

[KOPBET]

Do you have a vacuum gauge that you can check the ported manifold vacuum at the diagnostic switch during below 80 degrees versus above for differences?

Does the signal from the diagnostic switch operate above 80 degrees as well as below 80 referrenced at the ECM?

Are you sure the vacuum source is coming correctly from a ported source? (had to ask).

Have you checked/cleaned carbon in/from manifold under the EGR?

My pennys worth.
Good luck.