bad egr??
Thread Starter
Racer
Joined: Jun 2001
Posts: 435
Likes: 0
From: How did I get here? AZ
bad egr??
What problems would a bad egr valve cause at idle and throughout the rpm range? Say, on an 85 vette. I don't really understand what a bad one would do, or under what parameters the thing operates. I know its supposed to divert exhaust back through the intake for emission reasons, but when and why?
Pro
Joined: Dec 2000
Posts: 700
Likes: 20
From: Derby Kansas
Re: bad egr?? (want2drivemy85)
Regardless of what some on this board may claim, don't just "leave it because it doesn't matter". Either fix it or get rid of it completely.
It should be closed at idle. If it's open it could cause anything from a rough idle to a no start if open enough.
It should only be open at part throttle. The computer uses inputs from different sensors like engine temp, manifold air temp (I'd have to check my Helm's for others) to determine when to engage the EGR. Other than a possible "Check Engine" light, I don't think you'll see anything.
At full throttle it should also be closed. If it's open you're allowing hot exhaust air into your intake which will cost you power.
It should be closed at idle. If it's open it could cause anything from a rough idle to a no start if open enough.
It should only be open at part throttle. The computer uses inputs from different sensors like engine temp, manifold air temp (I'd have to check my Helm's for others) to determine when to engage the EGR. Other than a possible "Check Engine" light, I don't think you'll see anything.
At full throttle it should also be closed. If it's open you're allowing hot exhaust air into your intake which will cost you power.
Pro
Joined: Dec 2000
Posts: 700
Likes: 20
From: Derby Kansas
Re: bad egr?? (want2drivemy85)
If your fingers are long & skinny enough you may be able to reach up underneath and feel for it.
Or use a small inspection mirror to look at the underside of it. You'll have to get creative to find an angle and location to get the mirror under the plenum for a good view.
Or use a small inspection mirror to look at the underside of it. You'll have to get creative to find an angle and location to get the mirror under the plenum for a good view.
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