Cleaning the EGR control box

[crazylikeacat]

Hi,

Are there instructions for cleaning the components of an EGR control box? My car is a 1986 Accord LX (manual 5-speed).

Is this a reasonable alternative to having the box replaced?
best,
m

[derolph]

Yes, it's a reasonable alternative. If you do it, you should replace the gasket. For a long write-up on this, see http://www.hondaprelude.to/forums/showthread.php?59722-How-to-Clean-your-EGR-Valve

Of course, if you conclude that the EGR valve is defective, then you'll need to replace it.

[crazylikeacat]

Thanks but isn't the egr valve separate from the egr control box? Am I right in thinking that the box even has its own valve - the egr "control" valve, not to mention a host of solenoids and tubes? I'm a newbie so sorry if this is wrong.
-m

[DBMaster]

Hey, Cat, what kind of Accord do you have? It's not listed in your ID. There is no control box that I know of in the fuel injected model. I always took the approach that I would rather spend the money up front and get new components rather than trying to rework tired, old stuff that was not intended to be reworked. I had EGR issues, spent $140 for a new EGR valve/sensor assembly, and never looked back.

[crazylikeacat]

It's a 1986 Accord LX/5-speed/manual/carb i.e. not fuel injected.

I took that approach, DBM, but my replacement EGR box ($270) turned out to be incompatible with my engine. The different engine types from 1986 have different EGR boxes.

Maybe it's worth trying again, but in the meantime would like to know if there's a method for getting the EGR box cleaned and working again.

Is it more complicated than checking the internal tubes for vacuum, cleaning the solenoids and valves with carb cleaner?

-m

[Vanilla Sky]

You mean the black "mystery box" tucked in the back passenger corner of the engine bay? There isn't a specific cleaning method, but the service manual has the vacuum diagrams and testing procedures for all of the valves in that box.

[pickupman6]

^ check the manual, if you don't have one here is one you can download. Maybe you will be lucky and dr snooz can give you a link to the 89 accord manual. The carb section is the same for all 3geez I believe.
About the only thing you can really clean in there (at least for fi version) is a little canister with 3 hoses hooked to it. I cleaned mine out with brake cleane. I also sprayed som wd40 in the cvc valve( green and white doodad) and blew it out with very little pressure. Like maybe 10 psi, my compressor only goes down to 40 so I emptied it out, turned it on and immediatly blew out the cvc before the pressure built up. Then I sprayed a little pb blaster in the egr solenoid and hooked it to the battery a few times to cycle it through there and flushed it out with some white lithium grease, and cycled it a few more times. Then put it all backtogether. Still had the dangd ol light. Popped the top fo the egr off( the lift sensor) and put a bead of 3m weathersripping and gasket maker (black tube, yellow glue) under the oring gasketmaking sure that when I pressed the gasket into the groove some glue would squish out. My egr has been working fine ever since. That was about 4 months ago. I'm curious though, what makes you think you have a problem with the egr? Emissions? I just remembered after typing out that whole thing your car probably doesn't have a lift sensor. Sometimes the egr ports in the intake get stopped up, and that's not something I would recomend trying to fix if you don't know exactly what you are doing. Oneway to test that would be to pull vacuum on the egr valve while the car is running. If it stalls the ports are probably ok. If it doesn't then either the egr valve is leaking, stopped up, or the egr ports in the intake a clogged up with carbon.

[crazylikeacat]

Yup the "mystery box."

Thanks for those leads. It will be a week before I can implement them - or have a mechanic try. I'll report back then.

-m

[A20A1]

The whole setup is meant to stay clean. It's in a reasonably sealed box, and every solenoid or orifice open to the air is capped with a mini air filter. As long as the filters are in place and clean you should be okay. The only problem I see is constant reversion or a PCV problem maybe getting small contaminants in some of the lines closest to the manifold but I doubt it would reach the box.

Solenoids may stick, or outright fail from time to time but I don't know the best method to clean and lube them up. pickupman6's method seems reasonable though.

http://www.3geez.com/forum/attachment.php?attachmentid=4543

[DBMaster]

Yeah, when I was getting my code 12 I spoke with my mechanic. He said EGR valves RARELY go bad so I went for the control box stuff first. I basically wasted money replacing the EGR related parts in the box (bought from Majestic Honda new). Ultimately, the problem was the uneven opening of the valve. It was perfectly functional, but as long as it stuck slightly during the opening process I got the CEL. I cleaned the valve and tried lubricating the shaft a bit to no avail.

I'm afraid I can't really help any further as I believe the carbed model uses a different (and hopefully cheaper) EGR valve/lift sensor assembly.

[pickupman6]

Dang, that's what the inside of a carb majic box looks like? Even the egr setup is completely different, I mean completely, what I said in my last post won't do you any good at all. I shouldve checked my manual.

[Dr_Snooz]

Maybe you will be lucky and dr snooz can give you a link to the 89 accord manual.

Oh crap. I missed my cue. Sorry.

http://honda.roadpwnage.com/manuals/pages/usdm-accord-1989-full.php

For anyone who cares, the link to the manual is on the 3geez wiki.

http://3geez.wiki-tv.com/Main_Page

I usually just type "3geez wiki" into Google to find it. Follow the "Download the Honda service manuals" link to get the manual.

[pickupman6]

I didn't want to steal your thunder lol