EGR Valve
09-26-2003, 11:12 PM
#1
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EGR Valve
I think my EGR valve is not functional. I push on the diaphram and no change in RPM. Is it ok to pull this out, or should it be replaced. Could it be causing a vacuum leak?
09-27-2003, 03:31 AM
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Re: EGR Valve (Dk Met Grn 80 L82)
Could be just plugged with carbon. Use a vacuum pump and check to see if the EGR is holding vaccuum. You can also use the pump to open the valve whent the car is running. Should be a change in RPM. If not, but a new EGR gasket and pull the EGR valve. Check to make sure the ports aren' t all plugged and clean out any carbon the valve, should move freely.
Good luck
:thumbs:
Good luck
:thumbs:
09-27-2003, 09:38 AM
#4
Drifting
Re: EGR Valve (blackbirdpilot)
If you (with a glove on - it's hot ) pull up on the diaphram with the engine running at idle and it should run ruff and drop in RPM's. If not, then you have a bad valve or plugged ports.
Pull off the EGR, squirt carb cleaner in the ports, let it soak and then blow out or scrape out the carbon. Just don't soak the diaphram. Then use the vacuum pump and see if the diaphram and plunger moves - if it does the valve is probably ok.
Get a vacuum gauge or borrow one and connect to the line feeding the EGR valve. Rev the engine and you should see vacuum go from 0 to about engine vacuum. If not, chase this down.
If the valve is ok and there is vacuum, then the ports in the intake manifold are plugged with carbon and the only real way to clean them out is to pull the manifold soak them with cleaner and use a brush and coat hanger to get it out. You really don't want to risk poking a wire into the port and breaking a chunk of hard carbon off and getting into somewhere it is not supposed to - like the engine internals.
Pull off the EGR, squirt carb cleaner in the ports, let it soak and then blow out or scrape out the carbon. Just don't soak the diaphram. Then use the vacuum pump and see if the diaphram and plunger moves - if it does the valve is probably ok.
Get a vacuum gauge or borrow one and connect to the line feeding the EGR valve. Rev the engine and you should see vacuum go from 0 to about engine vacuum. If not, chase this down.
If the valve is ok and there is vacuum, then the ports in the intake manifold are plugged with carbon and the only real way to clean them out is to pull the manifold soak them with cleaner and use a brush and coat hanger to get it out. You really don't want to risk poking a wire into the port and breaking a chunk of hard carbon off and getting into somewhere it is not supposed to - like the engine internals.
09-27-2003, 08:34 PM
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Re: EGR Valve (bigvette1)
That is exactly what I did. Push in on the diaphram and there is no change in RPM. Also there was a pile of carbon like crud laying on the top outside of the intake manifold just under this valve. I figure the valve must be toasted. I just wanted to know if I should just leave it as non functional, pull and cap off somehow, or replace? Is there any harm leaving as non functional besides maybe a rougher idle?
09-27-2003, 11:43 PM
#7
Drifting
Re: EGR Valve (Dk Met Grn 80 L82)
The only negative of blocking off the EGR or having a non working one is the carb was origionally jetted with the EGR feedback taken into account. Without EGR on an EGR engine you may run a bit lean. Check your jetting in concert with LARS paper on Q-Jet tuning. If you have emission testing you may have a problem on NOX tests.
