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pdupler said:
Not much can be gained. The EGR valve remains closed at idle and at wot and only opens during part throttle operation. Look inside the TB, at the top see a couple of tiny holes not very far apart. These lead to the vacuum connections that control the EGR. Valve opens only when the butterfly is positioned between the two vacuum ports, for instance when you're rolling at a steady 25mph on the emissions dyno. When accelerating hard, the valve is closed. If you want to test yourself, disconnect and plug the vacuum line at the EGR so it won't open at all and see if you like it any better. To make the experiment valid however, first make sure you're EGR system is working properly. A vacuum gauge connected at the EGR valve should show zero at idle, jump to 10 or so under normal acceleration up to cruising speed and should snap back to zero if you floor it or lift. If not, there is a problem in any of several vacuum components. Second, a vacuum pump drawn on the valve itself should cause the engine to stumble while at idle speed. If not, the EGR tube is blocked or the valve is not operational. Its pretty common that the EGR system becomes plugged up with soote over the years so your EGR system may have already disabled itself thereby saving you the trouble. :wink:

Phil D.

my mechanic had to jury rig my '82 to get it to pass smog a few years back. basically, the egr was on at idle speed which caused a rough idle. he put a ball bearing in the vacuum line to look normal, but the egr was bypassed. he engaged it manually to pass the test.

i would like to solve this problem myself (he's no longer my mechanic). what areas do you think i should concentrate on?

thanks :!:
 

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good advice christian. i'll check all those things.

thanks for the post :!:
 
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