No luck w/ my EGR valve

jsatcher · Posted: Mon Apr 05, 2004 7:30 pm Post subject: No luck w/ my EGR valve

My 81 El Camino's EGR valve's gone bad. Its a 267, and AC Delco no longer makes the valve. I've tried other brands, but it just runs worse w/ them on. Any ideas on what I can do to fix this? Any help is greatly appreciated.

Tommy · Posted: Wed Apr 07, 2004 4:09 pm Post subject:

Did you try one for a standard 305? I have one on my 350 that doesn't work, it's just for looks.(Emmision tests).
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78 Camino SS, 355,built 700r4,3.23
Gallery78 Camino SS, 355,700r4,3.23
MSGT 145 AW
NECOA #14

Hansmanbo · Posted: Wed Apr 07, 2004 5:24 pm Post subject:

Whats an EGR valve????????? Laugh

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York SC /1979 GMC Caballero / 350 Roller / Alum Heads / 410 posi

eighty_five_el_camino · Posted: Wed Apr 07, 2004 6:44 pm Post subject:

If nothing else, try the bone yard untill you find one that is good
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They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety.

Benjamin Franklin, Historical Review of Pennsylvania, 1759

Iceman · Posted: Wed Apr 07, 2004 6:57 pm Post subject:

EGR, it's on top of my list of emission controls I love to hate. When it works properly, it reduces the performance of your engine, when it doesn't work properly, engine performance becomes more of a suggestion than certainty. Fortunately, I haven't owned many vehicles with this parasite installed and the few I've had, I left everything connected but blocked the passages with a thin sheetmetal plate under the valve. That way I didn't have any vacuum leaks, exhaust gas leaking past the valve and by leaving the electrical connector connected, I didn't have any "Check engine" light in the dash and the powertrain control module was none the wiser since it can only monitor electrical circuits and not the amount of gas going through the valve.
How this system gained popularity among automakers is beyond me, in almost every case it does more harm than good. Intended to reduce the amount of NOx (oxides of nitrogen) from the engine, it kicks in at part throttle during cruising, letting exhaust gas into the combustion chamber to dilute the air/fuel mixture to lower chamber temperature. High combustion chamber temperatures create these NOx emissions and I've always felt that this system was invented in a hurry. Combustion chamber designs from the late seventies and up are quite up to the task of burning the air/fuel mixture more efficiently so pre-ignition is not likely to occur, even with slightly higher temperatures.
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Gudmundur Eyfells.
'68 El Camino
'69 El Camino
'04 Dodge Dakota

"I don't know where I'm going but they'll tell me when I get there."

jsatcher · Posted: Wed Apr 07, 2004 9:18 pm Post subject:

As far as emissions, they don't look to see what I got under the hood, but they test my exhaust. Will blocking it off hurt me in my tests? Also, if I run w/ no valve, won't it take forever to get my car warmed up and ready to go?

b4black · Posted: Thu Apr 08, 2004 6:02 am Post subject:

I hooked up a scan tool to my car. When I was going down the hiway, the knock sensor was couting up continuosly. (You can't here this knocking at 75 mph). These knocks reatrd timing, which means less performance. Replaced the EGR, the knocks are gone. Unless you can find another way to remove knock, keep the EGR. (or maybe you like replacing headgaskets Shocked

)

I don't see how it hurts performance. At WOT, it's closed.
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Rich
1985 El Camino Conquista - sold
1983 Regal T Type

doz · Posted: Thu Apr 08, 2004 10:02 pm Post subject:

Ive seen you post this stuff a couple times about the EGR fixing your knock problem.. There are other ways. Obviously if your engine knocks @ higher rpm you have a problem somewhere. Might wanna check other things IMO.. Theres plenty of engines that run w/ no knock w/out egr's. Mine doesnt knock, and no egr on it ;/ But its a 406

b4black · Posted: Mon Apr 12, 2004 9:13 am Post subject:

Obviously I have a problem???

Every shop manual I've read points to a bad EGR causing knock. The EGR lower combustion temps to lower NOx. Higher combustion temps lead to knock. Simple, IMO.

I don't have a problem with knock unless my EGR goes bad again. Your 406 is a poor example in this case because it not running the same type of engine management system. IF I could richen the mixture at part throttle, I could get rid of the knock, but then emissions would go up and MPG down.

Yes there are ways to get rid of knock. A functioning EGR is one way. And it not at higher RPM's, it's at part throttle that the EGR is in effect. It's disabled at high RPM's. Dealing with WOT knock is entirely different issue (timing, octane, compression, ignition, etc.)
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Rich
1985 El Camino Conquista - sold
1983 Regal T Type

Tommy · Posted: Mon Apr 12, 2004 5:09 pm Post subject:

An MSD box is another way to get rid of a slight knock.
_________________
78 Camino SS, 355,built 700r4,3.23
Gallery78 Camino SS, 355,700r4,3.23
MSGT 145 AW
NECOA #14

b4black · Posted: Tue Apr 13, 2004 5:44 am Post subject:

Yes, ignition upgardes are a good way to deal with WOT knocking, especially when you can adjust the advance (retard based on RPM). The MSD did nothing for my part throttle knock. I already had colder plugs, new 8mm wires, new cap/rotor and a hotter coil. Timing is factory.

I went though three EGR valves (I wouldn't recommend TOMCO). When each failed, it caused part thottle knock. New valve = no knock.

Most poeple unhook their EGR and never even consider part-throttle knock becuase you usually can't here it. But hook up a scan tool and you will see it (a scan tool is an excellent investment, IMO). It's not as damaging as knock at WOT, but it happens much more often (acute vs chronic).
_________________
Rich
1985 El Camino Conquista - sold
1983 Regal T Type