Bench Testing Electric EGR Valve?

By the way I do appreciate your input.

 

One more thing, I have decided to spend the time to learn how these electrical schematics work. Can you point me to online resources you might think are useful for noobies?

 

Just editorial: did you mean to say over-heated? Anyway, what you said is hilarious.

 

Yes it overheated. in frustration over the situation a forget to check my stuff.

 

I have a new pump coming on Monday so I would like to bench test it. I have the tech stream and I was wondering if someone could walk me through testing it so I don't install a bad pump.(I'm concerned about the supplier) this will also tell me if my issue is electrical or I have two bad pumps.

 

Because this is an EGR testing thread and we've veered into water pumps here, I've put a followup in your other active thread.

 

That's a great question!

As far as learning the specific conventions Toyota uses in their wiring diagrams, there are introductory sections at the front of the wiring diagram manuals, 20-ish pages' worth, on "How to Use This Manual", "Troubleshooting", "Abbreviations", and "Glossary of Terms and Symbols".

Sometimes there are copies of wiring diagrams being shared around online by people who didn't bother downloading those sections, and so they might be missing. On the other hand, those introductory sections aren't very car-model-specific and they don't change a lot, so if you manage to find a diagram for any Toyota model from about the right decade that has the introductory sections in it, you should be good there.

Of course if you are getting the diagram manual from the source in any of the ways Elektroingenieur helpfully compiled, you won't be missing any sections.

Sometimes your questions won't be so much "what does this symbol or marking mean on the diagram?" and will be more "ok, what do I do with this concept?" And if you are viewing the manuals or diagrams on TIS, take a moment to explore the tabs up at the top besides "service information". Check out "reference information" and "technical training".

You've got entire chapter sequences there of the same "University of Toyota" training the technicians get. I am not signed in at the moment to grab a list of the courses available, but I am sure there's a whole sequence there on electrical/electronic diagnosis.

Now, as complete as those courses are, there might be times when the question you're asking is more like "what's a pullup? What's a PWM duty cycle? What's a stepper motor?"

In those cases, you don't have an automotive electrical or electronics question, you just have an electrical or electronics question. So you don't need to be limiting yourself to purely automotive sources to give yourself background in that.

I am sure that, these days, there are great online resources for that. I am not very up to date on what they are. There seems to be a list of tutorials sites on Quora. The SparkFun folks seem to have some good stuff going.

Back in the day, there was an older procedure involving a fellow who was paid actual money to write on my homework and tell me when I was starting to get it, and that procedure still works too. (He retired—they decorated his cake as an oscilloscope—but there are other folks in that line of work.)

The book we used back then, by the way, was by Horowitz and Hill, The Art of Electronics, and it's still a thing and a popular one, being not just a good textbook but quite entertainingly written. A new edition just came out in 2015, and "The X Chapters" came out in 2020. (I'm thinking those guys should be about due for their oscilloscope cakes by now.)

I'm sure some others, maybe Elektroingenieur, will have other suggestions too,

 

I cant even get the damn phillips head screws to come undone to get off my EGR valve. You are way ahead of me. I even gave em a spritz of WD-40. I turned and both of them started to strip (I even used a different screwdriver on each)!. I read that you can put a rubber band inbetween a screw head that is starting to strip and the screwdriver. Might also try hacksaw and then a flathead. Frustrating!

But as I am looking at it I really feel I should get it off. I can see behind the valve where the pushrod is and there is a lot of exhaust gunk in there. I feel like if i could remove the valve and then move the pushrod I could clean up the inside and ensure that it has years left of smooth actuation and doesnt get gunked up. Is that what everyone else did?

I can kindof reach behind the valve where the pushrod is to clean now but I know im not doing a great job.

 

I managed to clean the Exhaust Gas Recirculation valve without disassembly, but with only 70k kms likely easier. Like you I found those screws starting to strip.

If there’s a next time I might try my (manual) impact screwdriver on them. Also, I purchased these on Amazon.ca:



XunLiu Grade 12.9 Alloy Steel Hex Socket Head Cap Screws (50, M5X16)

The above is nearly sold out, but there are similar. Hopefully compatible.

 

If you have compressed air available, something like the Lisle Seized Fastener Removal Kit (as I've mentioned before, need to go talk to those guys about a commission) makes super quick work of them, no damage to the screws.

 

How did you clean without dissasembly? Did you just do what was done in the Nuts about bolts video (wire brush around the push rod, spray some cleaner in) and then clean up the valve itself, or did you somehow push back the pushrod and then clean the passage?

So far I have just done what is shown in the nuts about bolts video.

 

I cleaned the valve face zone (with brushes and brake cleaner), same with the other end, just reaching in with brushes and rags. I also gently lifted the valve, prying up at the edge with a blade, spritzing brake cleaner and running a tongue depressor type paddle around the edge, working off the carbon.

 

Thanks - I like this plan. Thats what I will do.

 

THose screws or ODD stuck on there and will strip easy. I found best to get and impact driver or Smack them with a hammer and screw driver twist and smack at the same time. this will get them loose.

 

I had a similiar experience. I put a cork in one end and filled it with carb cleaner, brake cleaner, and oven cleaner. Each was allowed to soak for days without any luck. Then, I used a section of coat hanger wire to drill out each "tunnel" except the 2 or 3 near the edge that I could not get to. Then, I pressure washed it. I could see light through every tunnel except the ones near the edge.
I feel that if the carbon is baked on for too long over too many miles, the carbon is very hard to remove. Has anyone tried to burn it out? A self-cleaning oven burns away the spilled food.