My camaro has recently acting like its about to quit whenever at idle or sitting at a stop light. I got a hold of a Matco Scanner and the error codes its putting out is the EGR System and Rich Fuel Mixture. I put a brand new set of plugs in it and still didn't change anything. I just checked and a new EGR valve is ~ $80 from the parts store. I'd hate to buy a new EGR valve and put it on and it not fix the problem.. Anyone think that is what needs to be replaced? I think it is located underneath the plenum, but I'm not exactly sure what all I need to do to take the plenum off. Thanks for the help.

 

What was the EGR code? It's possible it's stuck open, but there are lots more likely causes (like sticky fuel injectors). Try disconnecting the vacuum line to the EGR. Any change? If not, you'll have to pull it and see if it's open to be sure. First I'd check and see if your fuel pressure holds when you turn the key off. Another common problem is a back pickup coil in the distributor. Put a timing light on all eight plug wires and see if it flashes evenly at idle.

 

You can check to see if egr is stuck closed by pushing in on the underneath side of it it should have slight pressure when you do. Do it with the engine off and cool. I think with vacua gauge it should pull about 10 incheshg wouldnt swear to it though.

 

From what I can remember it was code 32 for the EGR system.. To check it I will have to pull the plenum off right?

 

Right, just the upper part. It's not that bad. Get new gaskets though. The poster above mentions pushing on the diaphragm as a test, that's valid put it's pretty much impossible to reach with a TPI. It shouldn't have any vacuum at idle, only at a steady cruise.

Check out this page on code 32: https://www.thirdgen.org/egrdiagnose

 

Does the symptoms i described sound like the EGR is stuck or needing to be replaced?

 

A stuck open EGR will make it lean, not rich. Rich at idle usually means either bad injectors or misfiring (leaking fuel injectors or bad plugs, wires, pickup coil).

 

Well, I've only noticed the Rich code after driving 20 miles or so... According to that scanner its switching from rich to lean back and forth like it should

 

I had the exact same problem on my '89. I ended up blocking off the EGR hole in my manifold because I'm impuslive and I hate the environment.

But, yeah, it leans out the fuel at idle, and crapped out on me a bunch whenever I was at a light or even a stop sign. Runs much better now, but from what I understand blocking off the EGR is a double edged sword.

With a spray can of generic aresol cleaner and a $1.89 gasket material, you could clean the guts of your current EGR valve - the exhaust gas gums that thing up real bad - and it would probably go back to working.

 

Is it an actual gasket around the plenum? or more less a make your own with gasket material?

 

Go to any parts store, they'll have a gasket specifically for the EGR valve. If they dont you need about a 2x2 sheet and a pair of scissors.

 

Do you know if there are any gaskets around the plenum that i'll need to replace?

 

I've never worked on the 350 EGR, but if it's anything like the 305, you just pop the valve off the back of the intake manifold. Two bolts that are a pain to get to, close to the firewall. I had to take my throttle body off, actually, and had to replace that Gasket, too, but it can be done without doing that - at least I think so. A TPI is like alien technology for me, though. Im not exactly sure what it looks like back there, but it wasnt a huge project for me.

 

Ok, thanks for that info... Anyone know about if there is a plenum gasket that i'll need to replace?

 

THE test I was talking about was to check to see if it was stuck closed. I just looked at mine it has gaskets on the plenum runners. I have a 91Z28 350 tpi.

 

You'll need the upper plenum gaskets and an EGR gasket. It's a special high temp gasket. Regular cut your own material will burn away.

 

Thanks again for all the information... I will let you know how it turns out.