1990 Corvette 5.7 TPI Chasing a DTC32

[80vette80]

1990 Corvette 5.7 TPI Chasing a DTC32

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I wonder if anyone can help me, I'm chasing the infamous Code 32. I've changed the EGR Solenoid and the EGR Valve which was hanging up. I drive with a vacuum gauge T'd in just before the EGR valve and do not see any change in vacuum while driving at 65 MPH. Vacuum holds at 10" when the code comes in. I've gone through the test documents with the flow charts and diagrams. Everything seems to test ok. It comes in after the car is driven for a while and clears itself after cool down. Vacuum lines appear ok.
I have seen a post recommendation on an 85 model where the trouble was cleared by placing a one way check valve from NAPA (730-1347) in the vacuum line from the plenum to the EGR solenoid. I think I would like to try this but am not clear about (Plenum to EGR solenoid). I wonder if he means between EGR Valve and EGR Solenoid? Does anyone have any information on this fix?
I would greatly appreciate any help with this.
Thanks!

 

[vetteoz]

e

do not see any change in vacuum while driving at 65 MPH. Vacuum holds at 10" when the code comes in.

So you are saying you are not seeing vac applied to the valve to make it operate or vac is present at all times ( EGR valve would be open )?

I have seen a post recommendation on an 85 model where the trouble was cleared by placing a one way check valve in the vacuum line from the plenum to the EGR solenoid. I think I would like to try this but am not clear about (Plenum to EGR solenoid). I wonder if he means between EGR Valve and EGR Solenoid?

As I see it , a one valve valve on the vac line would mean there would be no closing of the valve after it was opened until the engine was stopped.The test for a bad EGR valve is to apply vac and see if valve stays open so obviously it has no leak down ability

 

[80vette80]

e
So you are saying you are not seeing vac applied to the valve to make it operate or vac is present at all times ( EGR valve would be open )?


vetteoz, Thanks for the reply, I am seeing applied vacuum that changes with applied throttle input. As I was driving as soon as I saw the code come in I glanced at the vacuum gauge and saw 10" of vacuum.

I went ahead and changed out the EGR valve, and the results are the same, it still generates code 32. BTW, I bench tested the old EGR valve and it was sticking.

I'm kinda at wits end with it as I don't know where else to look.

I really appreciate your help!

 

[BigJimZ16]

OK, now that you have changed to a new valve that we assume is fuctional... did you bother to check the passages leading to/from the valve?? Are the exhaust gases actually being recirculated??

 

[80vette80]

OK, now that you have changed to a new valve that we assume is fuctional... did you bother to check the passages leading to/from the valve?? Are the exhaust gases actually being recirculated??

Yes, I applied compressed air through both ports in the manifold. I removed the pipe that connects from the manifold to the exhaust manifold and blew through it. Also the exhaust manifold. From this I assume the exhaust gases are making their way through.