Hey guys. My car (87 GTA w/350, auto tranny) is spitting out a code 32 - sometimes. I replaced the EGR solenoid, but it still pops up randomly, even after clearing the codes. The idle is rough.

I did some playing around (engine at operating temp) and here is what I found (I am hoping someone can tell me if it is normal, and if not, what is):

Unlplugged vac line (solenoid to valve) at EGR - made no difference to idle, and there was no vac on the hose.

Unplugged vac line (solenoid to TB) at the throttle body - made no difference to idle, and there was no vac on the hose.

Just for kicks, I unplugged the fuel pressure regulator vacuum line on the plenum, and I got an obvious vac leak, but no huge difference in idle (it may have picked up very slightly).

So what should I expect, and is there anything else I can try short of replacing the EGR valve. Since there doesn't appear to be any vacuum on the valve, and the solenoid is new, is there somewhere else I should be looking?

Thanks for your help

 

Here is a way to check the EGR valve itself. .... On the underside of the valve the are somewhat of an opening... stick a screw drive up under there against the valve inside. Have someone start your car and let it warm up. Once its warmed rev it up while holding on to the screw driver with a little upward pressure. As he is reving it you should feel the EGR valve moving up. If this doesnt happen... the EGR valve might be stuck or broken... or something else in the system is not allowing it to move. If it moves you know the valve itself is good and something else is causing this. That is where I would start. Good luck!! Also check to see if your getting the right amount of vaccum at the egr. I dont know offhand what it is supposed to be

 

On the tech page there is a good write up by GMTech on the code 32. You can also test your egr valve by applying vacuum to the valve (ala mityvac). Alos does your EGR have the temp sensor in the base?

 

Thanks for the replies. How in the world can you get at the EGR valve to test it? There just isn't any room to get at it under the plenum.

I do believe there is the temp sensor on the base of the EGR - seems to me there is a wire attached to it, so that must be what it is.

I hate to pull the plenum just to find out there is nothing worng with the EGR valve, and of course you can't run the thing with the plenum off

What about the behavior I mentioned with the vaccum - should there be vac at the throttle body at idle?

 

The vacuum port on the underside of the TB is a timed port. If the throttle plates are adjusted properly for minimum air position, there should be no vacuum at the port in the idle position.

If the ECM is storing a '32', the temperature sensor about which RD is inqiring is indeed on the base of the EGR valve, and is used to diagnose whether the EGR valve is opening when it is supposed to. If the ECM detects a light load, operates the EGR solenoid, and doesn't get an input from the temperature switch within a specific time period, the '32' will set.

Sometimes, you just gotta go there:

 

Thanks Vader. Now I know the vacuum is correct. So a defective EGR can be a result of the temp sensor on the base in addition to a bad valve (diaphram)?

I had the EGR and solenoid taken to a guy to have them checked, and that is why I replaced the solenoid. He told me that the EGR valve tested good. But I don't think he would have/could have tested the temp sensor. Is that temp sensor part of the EGR valve assy, or a separate part? I just can't remember.

I have had the plenum off more times than I can count, so doing it is easy enough, I just don't want to go through the effort if it might be something else. But it looks like I might have little choice. Sigh.....

 

Eric I have a new EGR valve at the shop you can have for a cheap price. I used it on my car for about 1 month. I also have a new set of vacuum lines for the EGR if you need. I deleted my EGR to make room for my nitrous solenoids. Give ma a call. Jay

 

Eric, it sounds like your EGR valve could be stuck. Here is a test for you.

Does your car run rough just at idle when not touching the throttle at all?

Disconnect the Solenoid-to-EGR at the EGR valve. Put a vacuum hose on to the EGR nipple.

Now with the car running at idle. Put a vacuum on the EGR. You can use a Mity Vac for this - I just use my mouth (embarrassing to mention). The engine should run rough and stumble. If you notice a difference, then the EGR is moving. If you don't notice a difference then it might be stuck.

Also, if yours is like mine, then its a negative back-pressure valve. So, its going to lose the vacuum while its running, so the vacuum will have to be applied while its going.

To test the negative back pressure function. Apply a vacuum the EGR with the car off. It should hold. I apply suction then crimp the line and install my vacuum guage. Now start the car and the vacuum should go down.

You don't really need a Mity Vac, but it would be better!

 

I am not trying to ***** up Eric's post but the code 32 was set on initial start up. Is there anything else besides EGR that will set the code 32 when first running???? The EGR isn't even commanded by the ECM until open loop IIRC. Does that mean when the code 32 is set at start up that its the ECM testing EGR functions and finding fault with something???

The EGR holds pressure and moves freely on the shaft. The pintle also appears to be seating properly.

 

Code 32 means the following for (5.0 VinF or 5.7-Vin8)

- The temp sensor was closed on startup. (Meaning sensor thinks its hot!)

- The temp sensor was NOT closed and all of the following conditions were met and held for 4 minutes straight:

1) CTS >176 degrees
2) EGR Duty Cycle commanded by the ECM >48%
3) TPS Less than WOT but not at idle
4) No codes (21,22,33,34) present

 

Thanks for all the replies. And thanks very much Razor for stopping by. As he pointed out, we tested (actually Razor tested, and he used his mouth too ) the EGR valve and it does seem to be moving freely.

JA_Formula_89, this code was set on startup (totally cold):

1) The engine was stone cold, so VTS could not possibly be over 176

2) Can't comment on this

3) The car was at an idle. The SES stayed on for an hour long drive - twice

3) There are (were) no other codes.

The SES light has not come back on since - twice it came on in one day when started cold and stayed on for the duration of the trip. But I haven't seen it since.

The rough idle may be caused by my **** retentativeness as opposed to a real problem - Razor thought it was fine. But the mystery 32 still bothers me. Something must be up.

 

Eric....

If after clearing your codes, Code 32 pops up when the engine is cold. Then I think that is a pretty good sign its your EGR Thermal Diagnostic Switch.

Now, if I could just figure out my EGR problem!!!!

https://www.thirdgen.org/techbb2/sho...hreadid=249814

 

Hmm, if that's the case, I suppose I could swap out the temp sensor on the EGR - that is what you are talking about, right? If that sensor causes the code to be set will that also give me driveability issues, or is it more informational?

Razor, what do you think? Think I could trouble for that temp sensor off your old EGR to test? D'oh - should have tried that when we had it all apart, huh!?

 

Well Eric on my GTA I replaced the solenoid, the valve, the temp sender, the CTS and all vacuum lines and verified the continuity of all wiring back to the ECM. My code 32 still popped on when I first started the engine. I simply eliminated the EGR function in the ECM and removed all the associated hardware. I still have my new EGR temp sensor if you want to try it out.

Also any time the code is set it will make driveability go right down the tubes The car simply resorts back to the memcal for information rather than using info from sensors,ect. As you know it will give sluggish operation at best.

I have no room anymore for my EGR valve but I would still like to know the cause.

 

Yeah, I knew you wiped yours out. Funny thing... it hasn't set the code 32 (or at least the SES) since last Friday. I guess I'll just leave it alone for now since it seems to be running fine.

Thanks again

 

If the codes are clear it shouldn't cause a driveability issue. Once a code is set, I'm not sure what it will do.

Try disconnecting the sensor and see if the cold start error goes away. If so, its a start. Hopefully, you can find a connection joint somewhere up stream from the EGR Temp Diag Switch.

- joe

 

Razor, how can you eliminate the functions of the EGR in the ECM? I would like to dissable my egr on my 305H as well.82 TA, carbed.

 

That would be your EGR temp sensor in all likelihood.

82TA, go to the DIY prom board and do a search, you'll most likely find a few very good explanations.