SRRF

Hello all,
I have a 1990 Z28 with a 305 TPI and A/T.

I am having a real headache with the EGR System and believe I just failed my e-test due to it. I was hoping some of you here could lend me some guidance where to go next because I am stumped at this point. Bare with me on the long read...

About 2 years ago when I e-tested the car I had to replace the EGR valve in order to get it to pass. After replacing the valve the car passed but it was having drive-ability problems. It would stall out when slowing down or sitting at a stop/idle. I was informed by the garage doing the e-test that it was the solenoid causing the problems (since the valve was replaced for the test) in which I then replaced with an aftermarket AC-Delco one. Unfortunately the car ran like crap with the new solenoid (couldn't even drive it, unlike with the stock solenoid) because it wouldn't stay running without throttle being applied.

Now jumping to present day and where I'm at. I have assumed that it must be the EGR valve causing problems (defective one installed?) because I hooked a vacuum gauge up to the solenoid and took it for a run. The vacuum from the solenoid all seemed correct (pulling vacuum when throttle is applied and dropping to 0 vacuum when throttle is closed or at WOT) The valve however seems to be partially functioning. I can hear the diaphragm move when I apply vacuum and if vacuum is applied while the car is running it will stall out. The thing I did notice however is how much vacuum it holds and for how long. After numerous research readings and determining how to test a Negative Back pressure EGR Valve it appears you should be able to apply vacuum to the valve and it should hold it for 20+ seconds.

The valve on my car holds about 2 in. of vacuum for only about 6 seconds... I have bought a few valves to test them and the best I could do was holding about 4 in. of vacuum for 10 seconds. The most recent one I have that I am debating putting on is an AcDelco that holds 4 in. of vacuum for what seems like forever (I haven't seen it release the vacuum even after 1 minute).

Once again, apologies for the long read, hopefully giving all the details will help troubleshoot what it could be. So that's my current situation, I am debating replacing the valve because I'm now unsure what it is... it seems the solenoid is fine, and the valve just isn't holding the vacuum it should... there are no trouble codes being thrown (I did get the code 32 way back when I first replaced the valve but since it has been fine).

Essentially it runs flawless when the EGR system is plugged off but gives me a headache with it hooked up. I believe I need the system hooked up to pass the test and my guess is this is why I'm failing.

If anyone has any other suggestions to try or insight into this it would be greatly appreciated. I'll also note I have done numerous things to it over the last year or two (complete tune-up, injectors, sensors, etc.)

Here are the e-test results if anyone wants a peek... I also made the mistake of taking it for an e-test the day it went on the road from sitting over winter (for need to get insurance/plated it needed the e-test asap). I have a feeling doing so may have made it fail horribly also and driving it prior may have been a good idea.

I've also heard rumors that the test can pass without the EGR system? how true is this? If I could leave the system unhooked and just pass the car that would save me A LOT of headaches.



E-Test Results
Year: 1990
Make: Chevrolet
Model: Camaro Engine
Size: 5.0L



Thanks for reading and I appreciate any insight whatsoever.

rdhanded2

iTrader: (3)

Did you ever figure this out? I have similar issues.