My Daughters First Car

[markgray74]

Hey guys,

I just bought my daughter a 94 lumina Z34. It ran awesome the day i test drove it and when i drove it home. I decided to drive it to work today and something has happened. After i had about 80 miles on it i had come upon a stop light and noticed the car started idling really rough and had hesitation during accelaration from the light. I took it into a local shop and they told me it was the EGR valve. At almost $400 dollars i decided to google it and here i am. I saw where someone said you could run with out it, so i unplugged the EGR and it stall ran bad. I then took it off and cleaned it up, but this didn't work either. Should i ty a used one? Or is there something else i can try without haveing to start replacing all of the sensors. Please be kinad enough to spell out accronyms as i am new to this site e.g. i don;'t know what IAC stands for.

Thanks for all your help,
Mark

[bszopi]

This will at least help you with the acronyms, and might help you perhaps localize a problem.

As far as the issue being the EGR, I don't think so. I'd like to know how they came up with that diagnosis. Is the Check Engine light on?

[markgray74]

Yes the check engine light was on when i bought the car. (It was running good). I assumed it was the O2 sensor. They hooked it to a diagnostic machine and said it was EGR. I tried the two pronge key in the diagnostic module under the dash and it will not flash anything at all. Also you stated "This may help" but i didn't see anything for the acronyms.

Thanks,
MArk

Also they cleared the check engine light so its not on anymore.

[bszopi]

Yeah, guess it helps if I paste the link...

http://wiki.60degreev6.com/index.php?title=Detailed_Sensor_Descriptions

Since the SES light isn't on anymore, is it driving better? You may also want to take off the EGR and try cleaning out the passage into the plenum, as people have had that area clog before and cause issues.

On a side note, I envy you... I noticed your age and the fact that you bought this car for your daughter. I am just a couple years younger than you, yet I have just over 11 years until I get to buy my daughter's first car.

[d.o.h.c]

egr will make your car run like shit. You need to look and see if any hoses are disconnected. Put a vacuum gauge on the car and see what it reads. Vacuum gauges can tell you alot. If it is reading egr then buy a new one and put it one, it takes 5 min to put on. And be sure to replace the gaskets upper and lower or it will still idle wrong. I would bring the car to autozone and have them scan it. If they say egr, get a egr and reset the battery. If not then start diagnosing.

[bszopi]

Hey Mark, I saw you were in the Chat a few minutes ago. Head back in there and I'll talk to you.

[markgray74]

I did forget to mention that it runs really rich too, smell gas from behind the car. I took it to autozone and they could not conect to it, something about the connector was "special" for this car. I will go ahead and check vacuum lines and clean the plenum. I have until November to get it ready for her.

Thanks again,
Mark

[3100 MPFI]

1994 is that weird transition year where you can no longer scan your computer with a paperclip.

The EGR can get STUCK OPEN, and it will cause all kinda of problems.

A friend of mine had the clogged line, but it didn't cause any drivability issues. It just made it fail emissions testing.

I think your EGR might be in the STUCK OPEN pahse, and disconnecting it will not work to test it. I say go to a junkyard and get another one, or dish out the big bucks for a new one. It takes about 5 minutes to change. Just be sure you get the gaskets (upper and lower), or you might have issues later.

[Rhedalert]

When my EGR was stuck open on a 3.1L V6, it acted very similar to what you described.

[3100 MPFI]

I forgot to put in my first post, but my 1995 twin cam was doing the same thing and the EGR was stuck open. I stuck the EGR from my 3100 on there, and it ran fine.

er...

well, ran fine other than the fact the engine was knocking.