Should a EGR valve be opened during idle?
I have a 1975 230 gas engine and when I spray
crab cleaner on the EGR valve the rpms go up.
Is this valve defective?

EGR valve should not open during idling. I used to test it before I took my car for CAL. smog check by applying vacuum to the valve (to make it open) during idling. If the engine dies, the valve is good. I have not done that anymore since my friend got his smog check license many years ago.

WARNING: Spraying crab cleaner near the high temperature areas may catch fire. Propane gas is safer.

Feeding the propane gas via a small rubber tube to find vacuum leak. It sounds like you have a vaccuum leak near the EGR valve.

David


[This message has been edited by be459 (edited 05-17-2000).]

sorry carb cleaner. How do i remove this Ibelieve it may be leaking at the seal. What is the function of this valve? <BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by be459:
EGR valve should not open during idling. I used to test it before I took my car for CAL. smog check by applying vacuum to the valve (to make it open) during idling. If the engine dies, the valve is good. I have not done that anymore since my friend got his smog check license many years ago.

WARNING: Spraying crab cleaner near the high temperature areas may catch fire. Propane gas is safer.

Feeding the propane gas via a small rubber tube to find vacuum leak. It sounds like you have a vaccuum leak near the EGR valve.

David


[This message has been edited by be459 (edited 05-17-2000).]<HR></BLOCKQUOTE>

The valve routes a small amount of exhaust gas back into the intake manifold diluting the air-fuel mixture that cools the combustion process. The result is less oxides of nitrogen emissions.

The EGR valve gets the vacuum from the carburetor port but that vacuum port alone is insufficient to open the valve. As the exhaust gas pressure increase due to increase in engine rpm, the extra boost is applied to the other side of the diaphragm that lifts the valve open.

I have never worked on the 230 gas engine. I do not know what else I can tell you.

David