CEL code 32 EGR Valve (VG30E)

[St00pkid]

I just bought a 1992 VG Hardbody. On my first day out and about driving it, it threw a CEL. Pulled the code and it gave me code 32. Trying to trouble shoot it I held the egr valve diaphram closed at an idle and the engine started to struggle a bit but never fully stalled out. I also had someone bring the rpms up to 4000 at an idle and there was no movement on the egr valve.

So I've cleaned out the egr, the carb cleaner coming out was slightly brown in color but nothing too drastic, and afterwards I could see the silver metal of the rod inside from one of the ports. Got a new gasket today from NAPA and popped that little sucker back on. Started the truck up to try my trouble shooting tests and nothings seemed to change.

When idling and pressing up on the diaphram it sounds like the RPMs drop significantly, the engine definitely doesn't like it, but it still doesn't fully stall out. I revved the engine a bit (didn't have an assistant to help me this time so I can't be totally sure of the rpms, but i did give it a couple of solid runs with the throttle control from under the hood) and still no movement on the diaphram. Everything so far is the same as before I cleaned it.

I even disconnected the vacuum hose this time and gave it a good run with the throttle and not once did I get a vacuum from that hose. I've read conflicting things about whether the EGR will actually kick on during an idle but the FSM seems to suggest that it should be functioning even at an idle so long as the RPMs clear 2000.

Just as some additional backround info, ive checked the vacuum lines and all of them seem to be in good shape. They all look like they were replaced recently by the previous owner. The egr also looks like its aftermarket and I'm struggling to find a vacuum diagram that matches the set up I've got under the hood, so I'm not sure if the previous owner changed some of the vacuum system when replacing things. I'll post a picture of the set up under the hood later today.

I've cleared the code from the ECU and will drive it around for a bit tomorrow to see if it pops back on but at this point I'm not super hopeful that the CEL will stay off. I'd like to premptively set up a plan for diagnosing the problem further if anyone has any ideas. Thanks!

[PorknBeans]

I’m not too familiar with the VG30/33 motors. But the diaphragm should stall out the engine when pushed up under idle conditions and it should fully raise up when the engine is revved to 2500 rpm and again at 4000 rpm. Under vacuum from a MityVac or similar vacuum tool, the diaphragm should raise up and hold the vacuum(I don’t know the time requirements) and not allow the valve(diaphragm to drop). If so, it should be replaced. But verify, when you find a vacuum line diagram, all of the vacuum line connections. Use a smoke machine to test the metal vacuum gallery(metal tubes, if there are any). Also test the BPT valve(if it has one) and the EGR solenoid.

[KivPanther]

The code will only throw if there’s a problem with the EGR control solenoid. Check the connector for damaged pins or wires and check the vacuum lines coming from it. There’s three total. You can also check the solenoid operation by applying 12v to it and feeling/listening for the click. You say the EGR looks aftermarket? I would make sure it’s the right one then. There were different ones for the manual and automatic transmissions as well as cali and federal emissions.

[PorknBeans]

The EGRC solenoid should respond with the “click” within one(1) second of applying the 12VDC.

Resistance across both pins should show about 30 - 40 Ohms @ 77°F.

Air passage between Port A(inner most port to the solenoid’s housing)and Port B(next to Port A) with no air passage between Port A and Port C when energized.

Edit - To clarify, Port A & Port B are the ones next to each other. Port C is the lone port.

[jp2code]

You are getting good at this stuff, P&B. Glad to have you here.

In the d21_truck_1990.pdf Service Manual, EC-8 provides this picture of the Vacuum Hose layout:



EC-16 describes the EGR Control Valve and the EGR Control Solenoid Valve:



On EC-31 is a Trouble Diagnosis table. It shows that Diagnostic Procedure 8 is for EGR Function & EGR Control, and that is on page EC-104.



There are 5 pages to that diagnostic procedure, and page EC-104 confirms the Code 32 you received and says it is a Check Engine Light (CEL) item.



If you don't have a Nissan Service Manual, you can use the d21_truck_1990.pdf. Yes, it's for the 1990 version, but it is identical to your 1992.

Link: https://app.box.com/s/iiz6amr6qygiplu2v8jzyf0ix3vmm1w5

[PorknBeans]

Thanks JP!

Glad to help!

I guess I’ve been tinkering with this emission stuff for a minute. God knows I’ve been through the wringer with my truck’s issues. And to think I had it going good when I passed smog inspection with flying colors. Then the P1447 code came up and then here we go again!

Not to boast…but I typed that last post from memory. I could give even more detailed troubleshooting. But I wanted to get the OP going on fixing his truck.

[St00pkid]

Ah, thank you so much guys! I've got the next two days off from work so I'll definitely be spending a lot of time trouble shooting this. I'm starting to think based off the symptoms that it's the solenoid causing problems. From what I can tell the valve itself functions as it should, it just seems like its not recieving the vacuum when its supposed to, which would point to the solenoid controlling the valve. I'll take a good look at it tomorrow and go for a drive to see if the CEL pops back on and update on the results

[89'HBV6]

When were the vacuum lines last looked at/replaced? Search it out here for size, but get quite a few feet...

[cadillacdude1975]

I deleted the entire EGR system on my VG33 swap.

[St00pkid]

The vacuum lines look like they were replaced pretty recently. They all look in good shape and are soft to the touch. They're also all bright red which I don't think is how they came from the factory. I picked up some wire and aligator clips from the hardware store today and I have an extra battery at the house so I can see if putting 12 volts to the solenoid has any results.

I'm also not sure if these symptoms are related to the egr function but the truck idles kind of low (around 750 RPM) and fluctuates a bit while sitting at idle (in the 10s of rpms). At the low end of the fluctuation the whole truck starts to shudder a bit until it fluctuates back up.

The other symptom this truck has that id like to address at some point is that the exhaust is PUNGENT. Ive had it idling for a little while to troubleshoot this egr thing and when I came back inside the whole first floor of my house smelled like car exhaust. That one I'm gonna chalk up to a bad cat though...