EGR --- aaarrgh
Thread Starter
Instructor
Joined: Aug 2005
Posts: 153
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From: Spring Branch Texas
EGR --- aaarrgh
Hey everyone. Glad I found this forum. I'm a long time Buick Grand National owner -- and we have a similar community. Again, thanks.
okay, just bought an 85 Corvette. It's in nice shape and will be my daily driver. It's got 87k miles, and the 4+3 gearbox.
Couple of issues... the cruise doesn't work.. just doesn't do anything. Light doesn't come on.. and, again.. nothing.
Also, the car runs pretty good.. but, not perfect. The check engine light came on as I was about to buy it.. the guy had a mechanic hook it up to a computer and he came back telling me it was the egr. I'm guessing code 32 but, don't know for sure. The symptoms are rough idle and the light comes on at idle after a while.. it will go off eventually when driving on the highway. From all I've read about the EGR, that's backward from what it should do if it's a bad valve.
I pulled the EGR solenoid and valve off of my GN a long time ago. GREAT move as it's just a performance hog. Can I do that here? Should I replace this one? Could it be the solenoid? On the GN, it was on the side of the intake and very easy to remove.. I can't even see it on this vette.
Any insight and/or advice is greatly appreciated.
thanks
jp
okay, just bought an 85 Corvette. It's in nice shape and will be my daily driver. It's got 87k miles, and the 4+3 gearbox.
Couple of issues... the cruise doesn't work.. just doesn't do anything. Light doesn't come on.. and, again.. nothing.
Also, the car runs pretty good.. but, not perfect. The check engine light came on as I was about to buy it.. the guy had a mechanic hook it up to a computer and he came back telling me it was the egr. I'm guessing code 32 but, don't know for sure. The symptoms are rough idle and the light comes on at idle after a while.. it will go off eventually when driving on the highway. From all I've read about the EGR, that's backward from what it should do if it's a bad valve.
I pulled the EGR solenoid and valve off of my GN a long time ago. GREAT move as it's just a performance hog. Can I do that here? Should I replace this one? Could it be the solenoid? On the GN, it was on the side of the intake and very easy to remove.. I can't even see it on this vette.
Any insight and/or advice is greatly appreciated.
thanks
jp
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
EGR / Cruise
The EGR is under the plenum. Chances are it is bad, but check all the lines going to and from the EGR.
Check all vacuum line under plenum and this general area that run to cruise control. Bad/broken line or lines that are switched will cause cruise not to operate.
Welcome to the forum. Find a good repair manual...it will help.
Check all vacuum line under plenum and this general area that run to cruise control. Bad/broken line or lines that are switched will cause cruise not to operate.
Welcome to the forum. Find a good repair manual...it will help.
Drifting
Joined: Mar 2005
Posts: 1,923
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From: GA
Originally Posted by 85VetteBoy
The symptoms are rough idle and the light comes on at idle after a while.. it will go off eventually when driving on the highway. From all I've read about the EGR, that's backward from what it should do if it's a bad valve.
I pulled the EGR solenoid and valve off of my GN a long time ago. GREAT move as it's just a performance hog.
I pulled the EGR solenoid and valve off of my GN a long time ago. GREAT move as it's just a performance hog.
EGR a performance hog? No, if anything it helps performance by cooling the combustion chambers and keeping you out of detonation which the ECM will pull timing for.
Thread Starter
Instructor
Joined: Aug 2005
Posts: 153
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From: Spring Branch Texas
Hmmm
EGR was an okay idea IF they could've figured out a way to make one that wasn't so poorly constructed. I stuck open unit and performance is done. Also, it's recirculating so little exhaust.. I can't imagine it's benefit is much. After replacing 3 on the GNs through the years.. I've had much better results by just bolting on a delete plate and just running the hoses around the solenoid. I'm not dead-set on deleting it from the vette.. just looking for options. How big an operation is replacing it on my new car?
thanks..
jp
thanks..
jp
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Welcome to the Forum and congrats on your new '85 Vette. 
The EGR valve is under the plenum bolted onto the intake base, the EGR sol is attached to one side of the EGR valve, the EGR temp switch sits on the EGR pipe from the rear of the right header into the intake base. There is a diagnostic method on my site to isolate the problem. BTW, your EGR is a negative vacuum system so needs engine (i.e. manifold) vacuum for proper operation and testing.
The ECM checks for EGR shortly after startup and will throw a code 32 if it detects that the EGR switch is closed. The ECM calls for EGR during cruize when coolant temp is above 175deg F; it throws a code 32 if the temp switch is not detected closed.
Check the vacuum source to the cruize controller just above the battery. Check the cruize vacuum switch on the brake pedal to assure that it isn't stuck open. If necessary you can disconnect the cruize cable from the throttle and test it at idle by jumpering contacts on the controller. For this testing you will need a copy of the GM Shop Manual by HELM for your '85 Vette.
The EGR valve is under the plenum bolted onto the intake base, the EGR sol is attached to one side of the EGR valve, the EGR temp switch sits on the EGR pipe from the rear of the right header into the intake base. There is a diagnostic method on my site to isolate the problem. BTW, your EGR is a negative vacuum system so needs engine (i.e. manifold) vacuum for proper operation and testing.
The ECM checks for EGR shortly after startup and will throw a code 32 if it detects that the EGR switch is closed. The ECM calls for EGR during cruize when coolant temp is above 175deg F; it throws a code 32 if the temp switch is not detected closed.
Check the vacuum source to the cruize controller just above the battery. Check the cruize vacuum switch on the brake pedal to assure that it isn't stuck open. If necessary you can disconnect the cruize cable from the throttle and test it at idle by jumpering contacts on the controller. For this testing you will need a copy of the GM Shop Manual by HELM for your '85 Vette.
Team Owner
Joined: Jan 2003
Posts: 20,304
Likes: 240
From: Summerland B.C. Canada
Welcome to the forum
I deleted the EGR using block off plates and have had zero problems. Here is some info on a couple of your problems. This is from my 86 manual so there might be a slight diffence.
http://members.shaw.ca/corvette86/Code%2032.pdf
http://members.shaw.ca/agent86/Instr...%20Cluster.pdf
http://members.shaw.ca/agent86/Cruise%20Control.pdf
I deleted the EGR using block off plates and have had zero problems. Here is some info on a couple of your problems. This is from my 86 manual so there might be a slight diffence.
http://members.shaw.ca/corvette86/Code%2032.pdf
http://members.shaw.ca/agent86/Instr...%20Cluster.pdf
http://members.shaw.ca/agent86/Cruise%20Control.pdf
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Intermediate
Joined: Jul 2005
Posts: 34
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From: Syracuse ny
Ihave been getting the same code and my mechanic has ordered me an EGR valve. It has a diaphram in it and mine is slowly leaking. When I go short distance it doesnt give me the code but when I drive on high way I get it every time. Its a 70.00 part. He owes me so I'm not paying for Labor. Good luck!
Thread Starter
Instructor
Joined: Aug 2005
Posts: 153
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From: Spring Branch Texas
Thanks for all the help guys. I've got my work cut out for me. Some of the responses are giving me the feeling that the egr issue and the cruise issues just might be connected. I'm I reading this right?
jp
jp
Thread Starter
Instructor
Joined: Aug 2005
Posts: 153
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From: Spring Branch Texas
Originally Posted by AGENT 86
Welcome to the forum
I deleted the EGR using block off plates and have had zero problems. Here is some info on a couple of your problems. This is from my 86 manual so there might be a slight diffence.
I deleted the EGR using block off plates and have had zero problems. Here is some info on a couple of your problems. This is from my 86 manual so there might be a slight diffence.
thanks
jp
Race Director
Joined: Jun 2004
Posts: 13,956
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From: WI
For my sun faded guages, I applied Son of a Gun. I was using it on the dash and tried it on the guages witch were sun burned looking, it made them deep black. MUCH nicer! Use your fav plastic conditioner.
EGR remove the hardware then install a diode per the instructions on 65ZO1's webpage. Click on his sig.
EGR remove the hardware then install a diode per the instructions on 65ZO1's webpage. Click on his sig.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
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From: San Diego, Ca
A proper functioning EGR system is beneficial to performance as it cools combustion temps. That prevents detonation. If you have an EGR code at cruise, it probably has nothing to do with a valve that's stuck open. The code means that the ECM didn't get a signal that EGR took place when commanded. Either the valve didn't open or the temp switch, which grounds from the heat of the exhaust, didn't close. I'd check the vacuum lines and activating solenoid first, then the temp switch.
Drifting
Joined: Mar 2005
Posts: 1,923
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From: GA
Originally Posted by SunCr
If you have an EGR code at cruise, it probably has nothing to do with a valve that's stuck open. The code means that the ECM didn't get a signal that EGR took place when commanded.
Either way you'll need to remove the plenum to get at those parts.
Last edited by Morley; Aug 28, 2005 at 05:36 PM.
Race Director
Joined: Jun 2004
Posts: 13,956
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From: WI
"Aardwolf, have you successfully implemented that diode trick to fool the ECM??"
I removed the tube and solenoid that attaches to the thermostat bolt but haven't done the diode. I will be doing that shortly though. I stopped by my dads place and asked if he had any diodes, he handed me a box of ten thousand miscellanious diodes.
A quick look showed one that'd work, I just have to hook it in yet.
I removed the tube and solenoid that attaches to the thermostat bolt but haven't done the diode. I will be doing that shortly though. I stopped by my dads place and asked if he had any diodes, he handed me a box of ten thousand miscellanious diodes.
A quick look showed one that'd work, I just have to hook it in yet.
Team Owner
Joined: Jan 2003
Posts: 20,304
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From: Summerland B.C. Canada
Originally Posted by 85VetteBoy
Hey agent.. do you have a step by step guide on deleting the egr? Again, I've done it on many GNs.. but, there is NOT a byproduct of the SES light or code constantly coming on. On those cars.. I simply tossed the egr and all of the electronics going to it.. reconnected the vac lines.. and was done with it. No code -- no fuss.
thanks
jp
thanks
jp
Team Owner
Joined: Sep 2003
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
Originally Posted by AGENT 86
I only deleted mine because of the unsightly tube which also interferes with valve cover removal.
