I suspected my EGR valve (in my '89 coupe) may be faulty so, I followed the instructions in my GM Factory Manual. First I checked the EGR Solenoid. It checked good. Then the manual instructs me to connect my pump directly to the EGR Valve and apply vacuum. The book says it should hold for at least 20 seconds. Well, it doesn't. So, I removed it and purchased another. Before I installed the new Valve, I checked it with the pump. It also doen't hold a vacuum. I took it back to the store for another one. While in the store, I checked the second new Valve and it also didn't hold vacuum. The instructions for the replacement EGR Valve says it can't be bench tested. My GM Service manual says it should hold vacuum. IF I buy a replacement part, shouldn't it test the same if it's suppose to work the same?

Thanks
Big *****

 

my 86 failed emissions so i was thinking my EGR maybe the problem? but haevn't had time to check the manual yet. maybe it says it has to hold vacuum when the engine is running? just a guess, but thats werid the new one are doing the same thing??i'll keep check for this thread to see what you find out. good luck.

 

The EGR test procedure in my '88 GM shop manual says to apply vacuum though the EGR Solenoid, not directly to the EGR Valve.

Then it says to apply vacuum to the Valve and start the engine, etc.

When were you getting the code 32?

 

I have an '89 and I'm not getting a code 32. I'm uploading the page from my manual which I was using to diagnose the EGR. Using Mspaint, I circled the failing procedure which says to apply vacuum and it should hold for 20 seconds. It didn't hold. So, i purchased a new EGR and it didn't hold. When I tried another new EGR and it didn't hold, my head started to spin. If my original is suppose to hold vacuum for 20 seconds, shouldn't a replacement test the same.

 

MAYBE the valve(s) are not the problem for the lose of vacumm, maybe you have a leak in your test rig?
With your finger over the end of the suction hose, pump up a 25" vacumm and see if it holds until you remove your finger. If it doesn't then the rig is bad.

 

Making sure the test pump was good was the first thing I did when I found the EGR valve not holding vacuum. I wanted to be sure it was the pump was working ok.

Big *****

 

Can someone with a vacuum pump please follow the circled procedure above and tell me if it works on your EGR valve???????

1. Engine off
2. Apply vacuum to EGR valve
3. Valve holds vacuum for 20 seconds.

Thanks
Big *****

 

I recently had to do a bunch of work to my recently acquired 85. (injectors, FP regulator) I also had an EGR code (32 I beleive) and went through the same troubleshooting chart shown in this thread. I performed the tests shown, I pulled the vacuum directly on the EGR valve and it did hold, pretty much indefinitely let alone 20 seconds. The valve was actually quite new, having been installed by the previous owner.

A tip, if you replace the valve replace the EGR temp sensor while you are at it, it is only a $12-14 part.

Good luck.