garyhgaryh

Oh my 82 Celica GT, I had a simple EGR valve with no electronics (no wires going to it).
To test, I put vacuum on the port and see if the plunger moves (when taken out of the car). In the car, the car would stumble with vacuum applied.

On my 93 Civic VX, I tried that and the plunger does NOT move. The diaphram does hold vacuum up to 20 inches (didn't want to go higher), but the plunger will not move.
I pushed it in/out to see if it is seized, but it is not.

Is my EGR bad? I failed smog due to high NOx (~1800 PPM). Oh, putting vacuum on
that port while the EGR was on the car did not cause the engine to stumble.

Gary


Modified by garyhgaryh at 10:49 AM 8/6/2007

garyhgaryh

I can't believe no one knows how to do this?

This past weekend I tested two other VX EGR valves and the plungers don't move when vacuum is applied. I assume my EGR is not bad and I need a signal for the plunger to get vacuum.

Anyone? Surely someone here knows about EGR valves on the Civic VX.

Gary

thesmogman

You might need to the some backpressure to it. Plug it all back up correctly and rev the engine to and see if that will get it to move. You might need to stuff a rag in the exhaust pipe to create some back pressure.

Don't go above 10 in.hg. or you can blow the diaphram.

The manual says to take it to the dealer so it's no help.

But if you are applying vac and it doesn't open it up repl the EGR.

You can check to see if the ECU is controlling the vacuum too. Put the vac guage on the hose that goes to the egr valve and rev it up. you should see about 7 in.hg. from that line.

garyhgaryh

Yes, the plunger does move when the engine is rev'ed up.

You know, I just moved from Santa Cruz county to the Bay area. In Santa Cruz I didn't have NOx check, but in the Bay Area, we have some sort of enhanced smog check with includes the check for NOx. If I smogged my car in Santa Cruz, I would have passed! Argh! At least I did two years ago when I smogged the VX (and it passed with flying colors then and NOW, except NOx).

HC is 8-9 PPM. CO is less than 1% Nox is 1800PPM!
Gary


Modified by garyhgaryh at 7:33 PM 8/6/2007

thesmogman

So it is moving = good then.

Just looked at your HC numbers and they are very low = Might be time for an O2 sensor. What was your O2 reading from the report?

Also yes Santa Cruz is a basic area and no Nox testing there. They do the TSI (Two Speed Idle) test which doesn't check for Nox.
It also doesn't account for loaded conditions which we use to test them now on a dyno.

So take and plug the vacuum line to the EGR rev it to 2k and apply your vacuum to the EGR and see if the rev's drop. If they do then for the most part the EGR is working and maybe time for an O2.

Sorry to bounce around, I just have a little time right now.

phootbag

It is possible to have blockage in an EGR port. Btw, I had an 83 celica gt. was a great car.

thesmogman

Absolutely Carbon build-up will block off all ports and sometimes it will block off only two. It can block off the tube from the exhaust too.

garyhgaryh

Whoops...
This:

You know, I must moved from Santa Cruz county to the Bay area.

Should be:

You know, I just moved from Santa Cruz county to the Bay area.

I'm going to look for threaded plugs. I bought an intake manifold this weekend and I'm going to drill through the weld and clean it. I think the egr metering ports are plugged up.

Gary