EGR Sensor - Reset Computer?
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Racer
Joined: Jul 2005
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From: Weston Fl
EGR Sensor - Reset Computer?
I put in a brand new EGR Sensor (I believe that's what it's called..) because my old one had the cable melt away from it. Months go by, no prob.. now my SES light is coming on and the OBD I reader tells me that my EGR needs replacing.. do I need to reset the computer? I heard that in some cars, you have to reset the onboard computer after you replace it.
It's also telling me that my MAF is going bad on me.. what horrible news =(
Thanx in advance!
~Derek
It's also telling me that my MAF is going bad on me.. what horrible news =(
Thanx in advance!
~Derek
Le Mans Master
Joined: Dec 2004
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From: Myrtle Beach SC
St. Jude Donor '05-'06
There is no cable going to the EGR I know of it is vacuum activated.Egr fault should light the SES and give a code.I just went through an EGR trial.Fix the MAF reset the codes and go from there.Post your codes so we can see what you have.
Le Mans Master
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From: San Diego, Ca
'88 uses a temperature switch to monitor EGR. Since you've replaced it and if the wiring remains intact, suspect either the vacuum solenoid that controls it (mounted on the thermostat) or it's vacuum supply. That's teed off of a line that runs to the charcoal canister and often comes apart or simply breaks.
Race Director
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From: The Top of Utah
Originally Posted by Fork501
and the OBD I reader tells me that my EGR needs replacing.
It's also telling me that my MAF is going bad on me.. what horrible news =(
Thanx in advance!
~Derek
It's also telling me that my MAF is going bad on me.. what horrible news =(
Thanx in advance!
~Derek
RACE ON!!!
Thread Starter
Racer
Joined: Jul 2005
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From: Weston Fl
I always suck at terms. It's the temp thing, which goes into the tube w/ the shield around it, back by the firewall on the passenger's side.
The error codes were 32 and 36
I'm just going from the code book and it said EGR fault for 32 and MAF fault for 36 (I might have the codes and meanings crossed, but they're the basic)
~Derek
The error codes were 32 and 36
I'm just going from the code book and it said EGR fault for 32 and MAF fault for 36 (I might have the codes and meanings crossed, but they're the basic)
~Derek
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Originally Posted by Fork501
I'm just going from the code book and it said EGR fault for 32 and MAF fault for 36 (I might have the codes and meanings crossed, but they're the basic)
~Derek
~Derek
RACE ON!!!
Le Mans Master
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From: Myrtle Beach SC
St. Jude Donor '05-'06
If you did not pull the neg terminal for 30sec after your last fix to reset the computer it may be a stored EGR code.On my car I can read it with an "H" in front of it.You could do it now and check again when the SES light comes on to see if both or 1 is the problem.
Drifting
Joined: Mar 2005
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From: GA
Originally Posted by Fork501
I put in a brand new EGR Sensor (I believe that's what it's called..) because my old one had the cable melt away from it. Months go by, no prob.. now my SES light is coming on I heard that in some cars, you have to reset the onboard computer after you replace it.
For the MAF code (36= Burn off malfunction), replace the 2 MAF relays (power AND burn off) by the battery before going after the MAF sensor itself...Relays cost $15 ea, rebuilt MAF cost $150 minimum.
After doing the relays, disconnect the battery or remove the ECM/FP fuse tapped off the battery positive cable, for a minute. Reconnect, start the car and drive it at highway speeds for 20 min or so and see if the SES light comes on...If it does, check codes and post em.
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Thread Starter
Racer
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From: Weston Fl
Originally Posted by Morley
Since you replaced the EGR switch "months ago" and the SES light is just now coming on....No, you don't need to reset the computer fro replacing the switch. Fault codes are stored in the ECM for 50 engine starts or until the battery/ECM is disconnected. Having been months since the switch was replaced and the code is just now appearing..you have a new problem.
For the MAF code (36= Burn off malfunction), replace the 2 MAF relays (power AND burn off) by the battery before going after the MAF sensor itself...Relays cost $15 ea, rebuilt MAF cost $150 minimum.
After doing the relays, disconnect the battery or remove the ECM/FP fuse tapped off the battery positive cable, for a minute. Reconnect, start the car and drive it at highway speeds for 20 min or so and see if the SES light comes on...If it does, check codes and post em.
For the MAF code (36= Burn off malfunction), replace the 2 MAF relays (power AND burn off) by the battery before going after the MAF sensor itself...Relays cost $15 ea, rebuilt MAF cost $150 minimum.
After doing the relays, disconnect the battery or remove the ECM/FP fuse tapped off the battery positive cable, for a minute. Reconnect, start the car and drive it at highway speeds for 20 min or so and see if the SES light comes on...If it does, check codes and post em.
~Derek
Le Mans Master
Joined: Dec 2004
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From: Myrtle Beach SC
St. Jude Donor '05-'06
At this point I have to agree with CFI get the manual and troubleshoot.
It really helps if you mention what you have done to address the problem in your first post.I think you need to remember what "the other problem" was.
It really helps if you mention what you have done to address the problem in your first post.I think you need to remember what "the other problem" was.
Drifting
Joined: Mar 2005
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From: GA
Originally Posted by Fork501
I actually just replaced both of those relays. I forget what other problem I was having before, but I decided to replace those with what GM suggested should be replaced (the numbers were different from stock) maybe I should go back to the stock numbers..
~Derek
~Derek
Try this:
To check that the MAF burn-off is getting power, look for 12 volts at the MAF connector position E.
If you get a Code 36, MAF burn-off malfunction, it should immediately reveal itself at startup and it won't affect performance. '85 Corvettes will never show a Code 36, only '86-'89 Corvettes. You can check to see if the ECM is calling for an MAF burn-off by running the car for at least 5 minutes, and checking the black wire at connection F (circuit 900) on the gray connector. It should be grounded for approximately 30 seconds. This is the ECM grounding the wire to actuate the relay. If there is no ground, the ECM is at fault. If you have ground, check the power to the relay. If the relay is sending power to the MAF, check that the dark blue wire (position D) on the MAF sensor connector has power.
Thread Starter
Racer
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From: Weston Fl
Originally Posted by Redeasysport
At this point I have to agree with CFI get the manual and troubleshoot.
It really helps if you mention what you have done to address the problem in your first post.I think you need to remember what "the other problem" was.
It really helps if you mention what you have done to address the problem in your first post.I think you need to remember what "the other problem" was.
Originally Posted by Morley
No, the new P/N's GM gave you should be for the updated relays (they had problems with the old ones).
Try this:
To check that the MAF burn-off is getting power, look for 12 volts at the MAF connector position E.
If you get a Code 36, MAF burn-off malfunction, it should immediately reveal itself at startup and it won't affect performance. '85 Corvettes will never show a Code 36, only '86-'89 Corvettes. You can check to see if the ECM is calling for an MAF burn-off by running the car for at least 5 minutes, and checking the black wire at connection F (circuit 900) on the gray connector. It should be grounded for approximately 30 seconds. This is the ECM grounding the wire to actuate the relay. If there is no ground, the ECM is at fault. If you have ground, check the power to the relay. If the relay is sending power to the MAF, check that the dark blue wire (position D) on the MAF sensor connector has power.
Try this:
To check that the MAF burn-off is getting power, look for 12 volts at the MAF connector position E.
If you get a Code 36, MAF burn-off malfunction, it should immediately reveal itself at startup and it won't affect performance. '85 Corvettes will never show a Code 36, only '86-'89 Corvettes. You can check to see if the ECM is calling for an MAF burn-off by running the car for at least 5 minutes, and checking the black wire at connection F (circuit 900) on the gray connector. It should be grounded for approximately 30 seconds. This is the ECM grounding the wire to actuate the relay. If there is no ground, the ECM is at fault. If you have ground, check the power to the relay. If the relay is sending power to the MAF, check that the dark blue wire (position D) on the MAF sensor connector has power.
~Derek
Le Mans Master
Joined: Dec 2004
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From: Myrtle Beach SC
St. Jude Donor '05-'06
Haynes will not help go to Helminc web site and order the factory service manual.It will have the detailed flow chart for diagnosing every code in the car.Your original problem sounds like a fuel issue.Possibly the FPR,filter or pump pressure.
Thread Starter
Racer
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From: Weston Fl
Originally Posted by Redeasysport
Haynes will not help go to Helminc web site and order the factory service manual.It will have the detailed flow chart for diagnosing every code in the car.Your original problem sounds like a fuel issue.Possibly the FPR,filter or pump pressure.
The problem was with fuel. What I ended up doing was replacing all fuel injectors, getting my fuel system cleaned out (Ripoff at Meineke.. never again..) and capped the tube going from the FPR to the Plenum. Runs a helluva lot better, now.
~Derek
Thread Starter
Racer
Joined: Jul 2005
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From: Weston Fl
Originally Posted by Morley
The gray connector it refers to is on the burnoff relay, you want to check pin F on that connector
~Derek
Le Mans Master
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From: Myrtle Beach SC
St. Jude Donor '05-'06
Originally Posted by Fork501
As soon as I get some $$, I'm planning on getting me a Helminc book =) Guess it's finally time! lol
The problem was with fuel. What I ended up doing was replacing all fuel injectors, getting my fuel system cleaned out (Ripoff at Meineke.. never again..) and capped the tube going from the FPR to the Plenum. Runs a helluva lot better, now.
~Derek
The problem was with fuel. What I ended up doing was replacing all fuel injectors, getting my fuel system cleaned out (Ripoff at Meineke.. never again..) and capped the tube going from the FPR to the Plenum. Runs a helluva lot better, now.
~Derek
Thread Starter
Racer
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From: Weston Fl
Originally Posted by Redeasysport
Better get it first.If I read you right what you did was disable the FPR and have max pressure all the time at the rails.Not the way to fix it right.You have masked what may be a FPR problem.
Well I had put in the bigger fuel injectors (24#? I forget..) So I need an AFPR or one, which handles more pressure than stock. I haven't been doing so well w/ money lately, since I'm trying to get the thing paid off very quickly.. So I figure that since it's running for the time being, I'm safe.. if it blows up..... I just wasted a good $8k O_o;
I'm not really going to be able to "fix" my problems until I get it paid off *crosses fingers for April*
~Derek
Le Mans Master
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From: Myrtle Beach SC
St. Jude Donor '05-'06
If you disabled the FPR with bigger injectors it should be running way rich.I suggest you get the FPR straightened out first.Going from stock to after market(what kind) opens up all kinds of issues.It is best when doing this to get a tune done to adjust the computer to the injectors you have.You can bandaide it with a AFPR but I am not sure what it should be set to.You will need a pressure gauge to observe the pressure at the rails.I can guess with the injectors you have it should be aroun 38psi but that is just a guess.It is not more pressure you need it is less.The MAF if it is bad will cause you other problems.One thing you can try is to clean the wire on it some times it gets build up on it form the burn off cycle.Good luck
Thread Starter
Racer
Joined: Jul 2005
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From: Weston Fl
Originally Posted by Redeasysport
If you disabled the FPR with bigger injectors it should be running way rich.I suggest you get the FPR straightened out first.Going from stock to after market(what kind) opens up all kinds of issues.It is best when doing this to get a tune done to adjust the computer to the injectors you have.You can bandaide it with a AFPR but I am not sure what it should be set to.You will need a pressure gauge to observe the pressure at the rails.I can guess with the injectors you have it should be aroun 38psi but that is just a guess.It is not more pressure you need it is less.The MAF if it is bad will cause you other problems.One thing you can try is to clean the wire on it some times it gets build up on it form the burn off cycle.Good luck
Thanx for all of the help =)
I just looked up my fuel injectors.. they're the 22# injectors. I had bought the Pink-Top Bosch injects from Five-O-Motorsports on eBay back in September. I'll look up the PSI rate I should be running from them and get me an AFPR to go accordingly.
Thanx again!
~Derek