foobar'd EGR on 3.1 ga gt

[bremen242]

I'm been having a really hard time with my EGR system on my '94 grand am gt. it has a 3.1

I am getting the "egr XX solenoid failure". generally its code 75, but it has been 76 or 77.

I replaced the valve, obviously, that did nothing. After talking to a few mechanics, I pulled the TB and cleaned out the totally plugged EGR passage in the upper intake. I said "yay" because I thought it was fixed. (in the mean-time, I replaced the plugs and wires which fixed a bad driveablity problem). After driving it, the light will still come on when I am coasting down from 65mph or so, and stay on (btw, I pulled the negative terminal for a long time to clear the ECM). Today, I pulled the ECM, and checked the 3 EGR wires in the harness. No shorts, not ground, and I shorted each pin to one another to make sure I had good continuity to the plugs.

then I checked terminal D (the positive terminal that goes to the ERLS fuse in the fuse block). The only thing I could come up with is that I am reading 20 ohms of resistance from that to ground (with the fuse removed). Is this normal? I tried to track it down but lost the pink wire in the main harness over the tranny. ALLDATA says it goes to "10-WAY IP CONNECTER" then to the fuse block.. couldn't find any of that.

Any suggestions? I wanna shoot this thing many times and roll it down over the hill.

The only thing I can think of is that the ECM is FOOBARed or that the B+ wire going to the fuse block is grounded or something.

Also, if any one has a GA GT (94-95) can you burn any serious tire, or just chirp them from a start?

[MillenniuM]

The problem isn't in the EGR valve itself, i think that your problem is in the solenoid (switch) that controls the EGR, it is vacuum/electrical related, usually it is in the rear center of the engine, behind the throttle body. A vaccum line shuts in this solenoid, try cheking if the vaccum line is connected to the solenoid or from the solenoid to EGR, also check for a bad solenoid.

I disconected this in my car with no problems no ecm errors, only disconnect and close the vacuum line from the TB. Without EGR you will get more perfomance and mileage.

[bremen242]

I would love to agree; however, the EGR on my car is the digital valve with 3 solenoids and no vacuum hooked, like the old style (I like the older style better, easier to troubleshoot and only $50 to replace instead of $200). it is all controlled by the computer. I would love to connect it, but I have before, and the computer throws codes as well.

[geoffinbc]

I disconected this in my car with no problems no ecm errors, only disconnect and close the vacuum line from the TB. Without EGR you will get more perfomance and mileage.

WRONG. You will not get any better performance. You will get worse milage. You may also get pinging and detonation.

In order to compensate for not having EGR the ECM will have to pull back timing to prevent pinging. This will result in poor milageu. You are also killing the enviroment by releasing more NOx. So thanks for that

[bremen242]

Any info in fixing my EGR so I don't ruin the environment?

[geoffinbc]

Your 94 has a 3.1L? Is it not a 3100? Cuz my moms is a 94 and it has a 3100.

Anyway you know the valve works right? So for some reason the ECM cannot activate it correct?

I will look at the wiring schematics and see if I can think of anything.

[bremen242]

its a 3100. I didn't know there was a difference. I guess the 3100 has the distributor-less ignition?

I'll check to see if it will activate. I am assuming that isn't the problem since i replaced it with a new valve, but I will check it after work tomorrow.

[geoffinbc]

The only test I can find requires the use of a TECH 1.
You may be able to do it the old way and that is to apply power to each solonoid (while the engine ir running and EGR plug disconnected) as each solonoid is energized the RPM at idle should drop.

[geoffinbc]

Here is the Schematic