EGR tests good, but code 32!

[RaysnCayne]

Hey guys,

My R10's OG TBI 305 has been running rougher and rougher over the last couple months. I checked a few things (plugs, wires, coil, etc.) and found my EGR wouldn't hold vacuum. So I replaced it with a new one (tested before installing and works great). It seems to be less rough now. But after about 20-25 miles, my SES light came on and I found a code 32 - Faulty EGR.

Any thoughts or experience with this? All my lines to and from seem good and clean, no air leaks. IDK if my electronic actuator is working? Seems like it is.

It really puzzles me that I never got the first SES light with my old, very faulty EGR over the last couple-three months. But shortly after putting a good one on, NOW I get a SES light??

 

[edgephoto]

Are you sure the valve is working and is not stuck open?

 

[RaysnCayne]

I know it doesn't mean much these days, but the EGR valve is new, only about 20 miles old. It holds good vacuum when tested.
IDK if it's stuck open though. How would I check that?

I did just did a rudimentary suction test on the EGR control solenoid (switch) and can't feel/see any suction on either nipple that runs to the EGR valve line. That doesn't seem right. Or is it?

 

[gmbellew]

Were the passages plugged on the intake when you removed and replaced the EGR? If you apply vacuum to it at idle with the solenoid vac line off, the engine RPM should change due to the introduced vacuum leak.

If it is stumbling just off idle, I’d bet you have the wrong EGR type/part. There are two different kinds that look almost identical but function opposite internally.

 

[gmbellew]

There is a procedure to test the EGR system laid out in the drivability and emissions manual. I think the solenoid should not allow vacuum past it at idle. If it does, then it is stuck open and also needs to be replaced. On the side with 2 nipples, one is supposed to be an open/filtered port and one goes to the EGR valve. Other side of the solenoid goes to the front of the throttle body. Make sure the throttle body vacuum connections are correctly ordered.

 

[edgephoto]

The reason I ask if it is stuck open is you can get carbon chunks the get stuck in the seat of the valve. New or not the carbon will hang them up/

 

[Ricko1966]

I think has to be a wiring issue or the egr solenoid not the valve. That's just my gut on it. I'm going to do some research on code 32

 

[gmbellew]

code 32 sets when the system self tests at steady cruise/throttle on the highway. it will command egr operation and look at O2 data for the correct corresponding change. if it doesn't see it, it sets a code.

if you put a vacuum gauge on the valve side of the solenoid at idle, it should have no vacuum. if it has vacuum, the solenoid is stuck open.

if you have your old valve, do a good comparison of the features and make sure they are IDENTICAL.

 

[Ricko1966]

Almost every bit of the trouble shooting for this code is circuits. You won't be able to do a lot of the tests without a scan tool, but you can check for vacuum to the solenoid,you can see if there's vacuumm out(shouldn't be) I'd verify I installed the correct egr valve by number, visually check all these circuits,and check continuity of the egr solenoid. If it reads open you found your problem. If it has vacuum through it while it's unplugged,you've found your problem. If you plug it in and it gets vacuum through it,the solenoid is being commanded on when it shouldn't be. Check for broken wires and broken vacuum hoses,especially near the areas you were working on prior to the problem.

You must be registered for see images attach

 

[RaysnCayne]

Thanks for the info guys.
1. I have the correct EGR valve. It's exactly the same as my old one (which I believe to be the original) and functions the same as well.
2. I've tested the new EGR valve and it'll hold vacuum all day long.
3. I've got good vacuum through the plastic line from the TBI base to the inlet on the EGR solenoid.
4. I've looked pretty good and can't find any vac leaks in the EGR lines.
5. I've not uncovered the sheath from the wires. I'll do that and see if there's any broken/sketchy wiring.
6. I've got no vacuum from the solenoid outlet (either of them)
7. I replaced the solenoid just ahead of a long trip this past Friday morning with a new one. After replacement, everything remained the same: no vacuum from the solenoid outlet to the valve inlet. (Guessing maybe that means my old solenoid was probably fine and it's an electrical thing upstream?)

I drove it about 7.5 hours round trip this weekend. The SES light comes on about 20mins into my trip. (It'll be off after I start it back up after a gas or pit stop. Then come on about 20mins in.) I haven't checked the code since getting home yesterday. But I think it's safe to assume it's still 32.

I'm not good with electronics. And don't have a scanner. (Just a paper clip. ) But I have a multimeter and can check things as long I know where to place the probes and what values I'm looking for.

 

[gmbellew]

There should be no vacuum on the other side of the solenoid at idle. The solenoid only opens off idle. So the solenoid is not stuck open. But that doesn’t tell that it is opening when it should be. the first steps of the diagnostic indicate that if the ALDL is grounded A-B the solenoid should be open.

There could also be plugged passages in the intake. Disconnect the line from the EGR valve at idle and then manually open the valve by pushing the diaphragm or applying vacuum to the valve and opening it up. The idle should change because of the introduced air. if idle doesn’t change, the passages may be plugged on the intake manifold.

see attached for more details.

 

[RaysnCayne]

I tried idling it and manually pushing the diaphragm. It nearly killed the engine both times I tried this, so I think the intake passages are clear.
I tried getting the solenoid to provide suction on the outlet side by first revving the engine to about 2k and then jumping the A-B ports - neither seemed to create suction.

 

[Fat 454]

@RaysnCayne - buy a cheap OBDII scan tool and a book on the OBD system. Total investment under $50bucks. I have just done this, and it has opened up a whole new world of knowledge regarding how the OBD system was designed to work.

Bottom line is DO NOT just engage the "parts gun" to fix stuff. The OBD is actually a pretty good assistant to diagnosing engine control issues, often the issue is not the symptom being presented, but something else entirely. Latent codes can also be present theat have not yet triggered the Malfunction Engine Light, but are contributing to the problem.

Its like an old-school mechanic - you need to really understand what is happening with all the components, to figure out you issue. Its not always obvious. Case in point - we had a high idle on the Hilux - turned out to be a stuck Idle Air Control valve, not an air leak, TPS, throttle body sticking, O2 sensors, temp control, water sensor etc. etc.

 

[Fat 454]

I have been reading these 2 books. Really interesting stuff, given that my kids refer to me as "old school" etc, etc. and prefer the whole duct tape and carb approach.

 

[Fat 454]

Bought this cheapo scanner too off evil bay, however it has been quite good for the money - colour screen too !