The SES light has been coming on a lot lately in my 91 Camaro RS 3.1 I had it to GM and they told me it needed a new EGR valve which I couldn't afford at the time. I recently spent the $500 for a new one though and put it on. My SES light is still coming on though and my mechanic says it's being caused by the EGR valve. But I have a brand new one on the car. Any idea's of what it might be? While driving it to my mechanic's garage it was doing a lot of bucking and kicking, and the tack was jumping around like crazy. It did this for about the first half of the drive, then for the second half the car worked fine.

 

From what you are saying it sounds like it is open all the time.With the bucking and all.That is untill the engine is warm.You have a digital egr set up don't you?If so I don't know**** about that.If it's vacumn controlled,check all you vacumn hose going to and from the egr valve.Then check your egr vacumn control system.

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Kevin S
89 RS w/2.9
modded some but not heavily


"I am just as enthusiastic about flying saucers as I always
was, but the problem is that we are in the middle of a
long, long trough. There's only so many times you can pick
over old bones. There just aren't enough new sightings. It
is not like being a philatelist - there is always something
new to say about stamps."

- Denis Plunkett, 70, a retired civil servant from Bristol
who founded the British Flying Saucer Bureau, which has
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decline in the number of alien visitors to Earth.

 

i'll be sure to mention your suggestions to my mechanic. thanks for responding

 

Did yu check the connector when mine said it was bad it was a corroded and mngled connector.

 

camaros_guy
Where abouts in Nova Scotia are you?
When does your SES light come on, mine has been coming on lately, but only when I go over 120km/h.

Does your car hesitate all the time? Or is it stalling out on you?

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1987 Firebird
2.8L Auto
T-Tops
New Paint last Fall
No mods yet...

 

m friend is from NS do you guys know ho davie or kayley crowell is?

 

Thanks for the suggestion FAST RS, I'll get my mechanic to check that too. And no sorry I don't know those people.

I live on the south shore of N.S., near Hubbards and Chester Joe_L. And my SES light tends to come on when I'm coasting. I had a problem recently that took was causing my car to stall on me when it was warm, and I was coming to a stop. That turned out to be my computer and prom. Replacing those also solved the problem of my fan not coming on when it was supposed to.

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1991 Camaro RS, 3.1, K&N Air Filter..

 

I live in Pugwash, (Near the NB boarder, an hour away)

So it dies when it is coasting. My last car did that (87 Olds) but it was the MAF, and the O2 gone. But it would run really good cold, but when it got warmed up, you were scared to go around corners cause she would stall. Reverse was killer to, always die. But once i got those fixed, the car didn't stall coasting anymore...

Just my $.02

 

well mine isn't dieing. usually the SES light is just coming on when i'm coasting, but the other day on the way to the garage the tac was jumping around like crazy and the car was driving like crap.

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1991 Camaro RS, 3.1, K&N Air Filter..

 

Oh.. my... LORD! $500 for an EGR? Is it gold? I'd avoid your mechanic from now on.

Pull the computer code yourself- when the SES light comes on, the computer's stored an error code. The procedure's explained here: https://www.thirdgen.org/newdesign/f...gen.shtml#misc In the diagram of the ALDL (or, what they call a "DLC"; ALDL stands for Assembly Line Diagnostic Connector"), you want to jump pins 5 & 6 together. They're in the upper row, and they're the two rightmost ones.

With the car OFF, jump those wires together. Some use a paperclip, I use a piece of wire. Then turn the ignition key to "ON"- right before "Start/Crank"- don't start the car! Then count your codes as the link above says to do. You'll get code 12, then you'll get the rest.

Now, once the computer stores a code, it hangs out until something like 100 starts. So, if your mechanic happened to fix one code, it could still remain. Case example- to set timing on our cars, we unplug the EST-bypass connector. The SES light comes on, and the computer sets code 42, "EST failure". (No kidding, it's unplugged.) After we're done with timing, we plug the EST-bypass back in. The SES light goes out, BUT code 42's still in memory! This can cause confusion, because, say my SES light comes on again after I've set timing. Say the computer throws a code 45 (Oxy sensor, rich). When I go to check the codes, I'll pull up the 12 (normal), 42, and 45- now, did 42 come from me setting timing, or something else?

The solution? Clearing the codes. This is done by removing the negative cable of your battery for a bit; I usually leave it off for a minute. (You'll lose the radio stations too; if you have a delco-security radio, make sure you get the code first.) When you hook the cable back in, the computer's "fresh" of codes, and also "fresh" of what it learned. The computer will need to re-learn your engine and driving habits, so it'll drive like crap for a week or so- unless you give it what it needs. It needs to be driven at about 55-60 MPH for a half-hour away, and then a half-hour back home.

So all this comes down to is: Pull your codes. Reset your computer. Go for a drive, I'm assuming the SES light will come back on. Come back home. Pull the codes again. The codes from the 2nd time will be your "current" error codes. Hell, you might find out the EGR was never fixed!

Plus, you don't have a MAF, you have MAP...

Does the car always start fine? It's just when you're moving that it acts up? I wonder if you have an intermittant wire somewhere... possibly on the spark coil harness, or the computer's supply wire, or...


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

TomP, that $500 could easily be the dealer price. I checked the price of a digital EGR from Pep boys/AZone and it was like $300. It's still too much though. The vacuum EGR's were cheaper and had less problems.

 

Thanks TomP. If it acts up again I'll get hime to check that out. I'm not much of a mechanic myself. And yes CaliCamaroRS $500 was the price from the GM dealership. There's not many options around here to get one anywhere's else. Unless I want to put used one's on, which I've done in the past already. And I know it was put on because I went to the Gm dealership and bought it myself, and my father put it on for me.

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1991 Camaro RS, 3.1, K&N Air Filter..

 

Wow, for real? Man, I'm so happy I have the old vaccum-controlled EGR! Hey! Can a vaccum-controlled EGR be put on a car in place of the digital EGR??

What's the digital EGR look like? Er, well, how does it connect to the car?? How many wires?

Vaccum controlled EGR: Three pieces- EGR valve, EGR solenoid, EGR test switch. For activation, the ECM engages the EGR solenoid. The EGR solenoid allows engine vacuum to pass to the EGR valve and EGR test switch. The vacuum operates the EGR valve. If the EGR test switch sees "NO VACUUM", that means that the EGR valve didn't see a vacuum either- and that's what throws the EGR code.

Digital EGR: How does it work??

You're welcome on the code-reading procedure, camarors_guy. You don't -have- to go home, either... you can pull the codes in a parking lot or wherever. As long as you don't crank the engine with the jumper installed in the ALDL, nothing will be harmed. If you start the car with the jumper installed, you can fry the ECM.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

Basically, there are 3 small valves and the computer can control each individual one. I'd rather have a vac/EGR though..... Oh yeah, no you can't replace a digital with a vacuum....don't ask me why though. I have no clue.

EDIT: Tom i found this, check it out. I didn't know you could test the digital EGR: Digital EGR valves are unique in several ways. Only GM uses them. They are completely electronic, controlled solely by the PCM. They come in two or three solenoid models, depending on the application. Part of the valve is open to exhaust flow at all times. When the solenoid pulls the pintle open, exhaust leaves the EGR valve chamber and directly enters the intake manifold. This method is different from all other EGR valves. All other EGR valves open to allow exhaust to enter their chamber first, then circulate through the valve on to the intake passage. The benefit of the digital EGR valve is speed and accuracy. It meters EGR flow 10 times faster than a vacuum modulated system. The valve is actuated by an individual quad driver from the PCM for each solenoid the valve has. Battery power is fed through terminal D when the key is turned on through a 15-amp ignition fuse. When the PCM grounds a solenoid, a magnetic field is created that causes the armature to lift open the pintle. The PCM uses this system to actuate each solenoid in increments. The increments are displayed on a scan tool as percentages of total flow. With a bi-directional scan tool, the digital EGR valve can be commanded open in a variety of increments. Don't despair if you do not have a bi-directional scan tool. You can still work with this! It's easy. Simply unplug the four-wire connector. Run a fused 12-volt wire to terminal D and alternately touch each of the other terminals to ground with a test probe. This will cause each solenoid to pull open. You can do this test with the engine idling and check for an rpm drop as you ground each solenoid. If you don't get a good rpm drop on this or any other EGR valve, you may have plugged or restricted EGR passages, which can cause a code to be set.

[This message has been edited by CaliCamaroRS (edited June 15, 2001).]