garyhgaryh

I figured out a novel way of checking if the EGR passageways through the EGR cleaning ports are clogged.

My EGR cleaning ports are welded shut like this:



The only way to clean it is to drill through the weld.

Well, I bought another intake manifold from someone for $40 (Civic VX). I've been thinking of ways to test if this one has clogged EGR passageways. I thought about sealing the ports off and pumping high pressure air to see if air would come out the other side...

I woke up this morning and hit myself on the side of the head thinking there's an easier way to test whether or not this new intake manifold has clogged EGR passageways. All I need to do is turn the manifold up so the EGR passageway is facing the sky and fill it up with water. If the water drips through, then it's not 100% clogged. If that's the case, all I need to do is swap intakes and I should be able to pass SMOG (high NOx is causing me to fail right now - EGR valve seems NOT to be an issue so I assume it's the EGR passageway that is cleanable via the cleaning ports. On other cars, the cleaning ports are plugged and can be removed. On the 93 Civic VX and Preludes they are welded shut).

Any comments or suggestions?
Gary


Modified by garyhgaryh at 12:23 AM 8/18/2007

soros151

Watching this thread.

thesmogman

I have seen them drilled and then resealed. What you also need to check is if only one port is open. You can have three that are plugged and one that is open.

Just hold the manifold as if it was in the car and pour water down the EGR valve port and see if water pours out all four ports in the runners.

Have you checked the vacuum to the EGR valve yet? I have had a few that the EGR solenoid did not let enough vacuum to the EGR valve and they just replaced the solenoid in the control box (Black box) and passed.

I wonder if an acid bath would remove carbon?

TomO

I've always removed the EGR valve then used carb cleaner with the little red extension. You can bend it just far enough to spray it in the passageways and clean out the carbon.

garyhgaryh

I thought about hot tanking the intake manifold and I thought about buying six gallons of acid to give it an acid bath. I have a book mark of this somewhere so if you're interested, I"ll dig it up..

About my EGR valves, I put up to 20in of vacuum and the valve does not open. I tried it with two other valves and got the same result. So on the VX, I think I need a signal to the EGR valve for the valve to move when vacuum is present (correct me if I am wrong anyone).

I realize why there aren't too many post about these EGR valves - apparently, most Honda's after 90's don't have EGR valves. The only Civic with an EGR system is the VX.

Gary

garyhgaryh

Tom, will carb cleaner clean out carbon that is backed in there?

Wow, 314k miles on your VX eh? I just hit 230k.
Gary

TomO

If you have a GM dealer near you, you can get "Top Engine Cleaner" it is a liquid specifically for dissolving Carbon deposits. If you can't get that, then Carb cleaner or QD Electronic cleaner is the next best thing.

With the vacuum port on the EGR, it should be opening with that much vacuum on it. Take it off the car and decarbonize it and check again. Give the pintle a little friendly push if you have the Valve off the car to help it get unstuck. They tend to stick after the many years of being on the car.

Yuppers, many miles of great FE driving for me.

garyhgaryh

I tested 3 EGR valves and none of them move with that much vacuum on that port. The EGR valve is completely out of the car and disconnected. Although I could have had 3 bad EGR valve, I doubt it.

Gary

C Bass

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by garyhgaryh &raquo;</TD></TR><TR><TD CLASS="quote">The only Civic with an EGR system is the VX.

Gary</TD></TR></TABLE>

i believe the civic hf's had an egr system. sorry off-topic i guess.

thesmogman

You should only go to 10 in hg. for this. You might have blown out the diaphram.

The electrical connection should be for positioning only.

garyhgaryh

UPDATE--

Ok, I finally got some time about 30 mins ago so I decided to finally do what I posted I was going to do. I got the new used intake manifold I bought from someone on craigslist and poured water into the EGR passageway. Water didn't back up which was good, but eventually water came out of all four ports. Now, the EGR system is a closed system so I assume there is no other way the water can get to the other ports EXCEPT via the EGR passageway. So it looks like I got a good (mean cleaning EGR passageway) intake manifold.

I'm going out right now to work on the car. What I'm going to do now is pull out the intake manifold from my VX. Once out, I'm going to pour water in its EGR passageway. If water backup and instead of goes through to the runners, I'll be elated cuz that would mean I'm on track to fix this NOx issue. If water flows through to the runners, then I'm up **** creek cuz replacing my manifold with the new one isn't going to help. Wish me luck guys. I'll be back in a few hours.

Gary

garyhgaryh

Well, I ended up taking every off BUT the intake. I had to eat dinner and then I went to Walmart at 12am so I didn't get as much done as I thought. Pretty easy taking off the stuff around the intake. All I need to do now is just remove the bolts from the intake manifold studs and off it goes (I even got the intake manifold bracket off - I had to unbolt the bottom bolt since I started stripping the top bolt - decided to stop and take the backet off from the bottom bolt).

yoej8

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TomO &raquo;</TD></TR><TR><TD CLASS="quote">If you have a GM dealer near you, you can get "Top Engine Cleaner" it is a liquid specifically for dissolving Carbon deposits. </TD></TR></TABLE>

I'm a little off topic, but just as a heads up. Honda has these as well. I believe it's pretty much sea foam.

garyhgaryh

I finally got my intake manifold off.
I poured water down the egr passageway... it's a big clogged, but water still goes through. I'm goign to get some seafoam and clean out the spare intake manifold I have.

Where I can I get seafoam? Kragens?

Also, anyone have opinions of Felpro's intake manifold gasket for the VX?
Gary

95sloweg

You can get seafoam at a local auto store. Autozone, advanced, etc.

garyhgaryh

I cleaned out my intake with brake cleaner and techroline injector cleaner.
See how that works...
Gary

garyhgaryh

Whooho, I passed smog today!

Prev tests:

MPH HC CO NO
15 9 .02 1826
25 8 .02 1635

Today's test

MPH HC CO NO
15 38 .09 185
25 19 .05 178

I cut my NO by 10 folds!!!

So, how did I do it?
Of order of importance, I think:

1. timing from 16 to 13 deg
2. clean EGR passageway by replacing intake with a known good one (I would put that as #1 but my intake was not completely clogged when I tested it)
3. cleaned carbon from intake ports on the engine and new intake (esp near the injectors)
4. new plugs - one step colder gapped at .041-.043; original one was probably 5 years old and had a gap of .60-.70 when taken out
5. New air filter (probably did nothing - I should have kept the old one in since old dirty filter will increase HC (which is what I want).
6. Cleaned EAVC (screen plugged) - not sure if this can affect NO

I went in early before temps hit 100 deg. Last time I warmed up the car for 30 minutes driving it on the highway. Not this time. I drove it to the test only station 5 mins away turned it off and waited. Engine cold when the guy arrived. This should be #3.5.

My goal was to richen up the mixture somehow. I think retarding the timing helped, but not sure how it affects gas mileage. Since it's a commuter, I will probably advance it back to stock or higher.

Anyways, this smog saga has come to a close for me. I spend so much time on it that I was getting frustrated and was wondering if it was worth it. Since I commute about 120 miles/day, I can say it was worth it.

Gary


Modified by garyhgaryh at 5:45 PM 9/3/2007


Modified by garyhgaryh at 11:56 PM 9/4/2007