Okay, so I have a 1991 Honda accord. I am having problems passing smog. I checked the EGR valve, It was fine, no leaks on diaphragm or tubing. I cleaned the EGR passage ways on under the fuel rod and got new plugs. I opened up that box on the firewall and the EGR vacuum control valve has a vacuum going into the EGR control solenoid valve.
That is where the vacuum stops.
I tested the voltage with a multi-meter. The EGR valve lift sensor, the solenoid, and vacuum control. (Lift sensor 3-5v, Solenoid 12-13.4v, Vacuum 12-13.4v)

so,
1) How do I test if the EGR control solenoid valve is bad?

2) Is it possibly the ECU, and how would I check that?

3) What is an ERG lift, and would it interfere with EGR operation if it was broken?

Thanks for the help.
Honda Accord Wagon LX 1991

 

If you look on your intake there are 5 or 6 plugs which allow for cleaning of the passage at the intake port. You have to drill and tap. install bolt and use slide hammer to remove them. Clean it all up and install new plugs from Honda. Your NOX will go down drastically. I've done many in Ontario, CANADA.

Call your local Honda dealer for the plugs. Heres a link to the procedure. 3/4 way down the page

http://rotordesign.com/accordwagonblog/page/2/


Good luck.

 

You might check out this site.

home.comcast.net/~em-engineering/T2T013.pdf

 

Awesome link hoorah, bookmarked it already. I have cleaned and tested the EGR Valve manually(with my mouth) and my car sputters when I apply a vacuum to the EGR valve.
I did a flow chart from this thread https://honda-tech.com/forums/honda-accord-1990-2002-2/need-help-egr-vacuum-control-solenoid-diagnosis-3045994/ and everything points to the egr solenoid or ecu. I don't know how to test either one though.

 

If you're getting an EGR CEL and a sputtering take off at about 2k your EGR ports on your runners could be clogged, same with the actual solenoid on the top of your IM. Just take your fuel rail off and clean or drill out the ports under the cover while holding a vacuum above it to suck up all the dirt. Then replace the gasket. You can clean the solenoid ports the same way, although you can take the actual unit off the car. Had to do mine a few months back, now I have it removed so no biggie here.

 

what part of the smog are you failing. The car should just about stall..not just sputter. If its nox you're failing, send me max allowed and actual.

Thanks

 

max allowed for NO (778)
Mesured NO (2679)

I changed a few things since this article. and no pass on the smog still. I narrowed it down to 2 for sure things.
EGR Solinoid, or ECU, Im going to do a continuity test on the EGR solinoid on sunday. I will follow up and let you guys know what happens

 

I tested the egr solinoid, and IT WORKED... and the replacement as well. . For some reason the solinoid is not being grounded by the ECU while the engine is revved above 2000 RPM's. So I have to check the wiring and ECU ECM and test it thouroghly, lame. I saw this issue on a few other forums and it has yet to be solved, so I will post the fix here, if I find out the cause of the problem.

 

I direct wired my EGR solenoid and it would click on and off but had no vacuumn. Turned out it was just a blocked port. If you haven't already you may want to check it

 

What you need to do is run a t fitting in between the solenoid and the valve and run a vacuum hose into the car through the firewall behind the charcoal canister. There is a rubber grommet. Just remove it and run the vacuum hose inside the car. Put a vacuum gauge on it and look at it while you're driving. If you see vacuum while cruising then obviously it's working. I'm not so certain that egr works at idle.

Also, make sure that the port isn't clogged as already has been suggested as a possibility. Ground the solenoid and when it clicks check to see that vacuum goes through the solenoid by applying vacuum on the port and it should not hold vacuum if it's open like it should be after being grounded.

If it checks out ok then the problem is the egr ports which is quite common. This is probably what's causing you to fail smog.

 

oh and one more thing....egr itself doesn't function until the car is completely and totally warmed up. If you're testing while the car is cold or only slightly warm let it idle for ten more minutes or until the fans have cycled on twice.

 

Question about those replacement plugs purchased from Honda: When installing them, does the cupped/hollow side face up? And, if they ever had to be removed, any idea how that would be done? I presume the original aluminum plugs do not need to be drilled all the way through to pull them out but the hollowed replacements would surely have to drilled clear through unless they can be removed some other way.

 

hollow side up...you would drill through the middle then stick a screw thats slightly smaller...attach slide hammer...pop out


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OK, thanks. I think I may be doing this to my 91 Accord.