rough idle,poor performnace

[drazenv]

Experiencing rough idle and low vacuum 10"HG.Replaced intake gasket ,still same problem.Car stays in "open loop"was told the there is a EGR gasket under the top manifold that needs replaced,the only EGR gasket that I saw was the one underneath the EGR valve itself.Looked in the GM parts manual and don't see this gasket either,does anyone know of what gasket this guy is talking about?

 

[GerryLP]

Experiencing rough idle and low vacuum 10"HG.Replaced intake gasket ,still same problem.Car stays in "open loop"was told the there is a EGR gasket under the top manifold that needs replaced,the only EGR gasket that I saw was the one underneath the EGR valve itself.Looked in the GM parts manual and don't see this gasket either,does anyone know of what gasket this guy is talking about?

The 81 Vette uses a plate between the manifold and the EGR to avoid contacting the valve cover (in fact, it will not install flush if using stock valve covers or unmodified). The plate is basically in the same shape profile of the EGR's base. It takes a gasket between the plate and the manifold and another gasket between the EGR and the plate.

See if it has one.

 

[drazenv]

no plate

The 81 Vette uses a plate between the manifold and the EGR to avoid contacting the valve cover (in fact, it will not install flush if using stock valve covers or unmodified). The plate is basically in the same shape profile of the EGR's base. It takes a gasket between the plate and the manifold and another gasket between the EGR and the plate.

See if it has one.

My vette is a '84,I'm sorry if I didn't clarify,but I checked for the plate and there wasn't one but I did block off the EGR ports with a homemade plate and still havethe same problem that's why I think I should look elsewhere.Any ideas?I don't have any trouble codes,but I can't get the CEL to flas "Open LOOP"when I jump the test connector.Possible ECM defect?

 

[GerryLP]

My vette is a '84,I'm sorry if I didn't clarify,but I checked for the plate and there wasn't one but I did block off the EGR ports with a homemade plate and still havethe same problem that's why I think I should look elsewhere.Any ideas?I don't have any trouble codes,but I can't get the CEL to flas "Open LOOP"when I jump the test connector.Possible ECM defect?

Rough operation and no codes seems to be vacuum leak. But it could be ignition related. A bad oxygen sensor could would cause a problem, but it should trigger a code.