egr


Preface: I worked on the EGR port clean out task finally on my 1991 Accord EX. I tried to used some 6″ pry bars that I found at the hardware store to keep from having to remove the fuel rail or the IAVC and the FITV. These tools did not work. The fuel rail, FITV and IACV needed to come out, if nothing else, so that they don’t get damaged, due to the force required to remove or install the egr plugs. No short cuts here.

Bigger pics:If you want to see any of the pics at full resolution, here is the url where I am keeping them. Any pic with a _1 is reduced in size for this thread. The others are full res. I wasn’t sure if it was ok or not to post larger pics. So I went with 640 x 480 shots. http://rotordesign.com/accord/egr/

Here are the links to the other helpful egr threads that I found. They all offer something. You should read them all.

http://honda-tech.com/showthread.php?t=1844067
http://www.preludepower.com/forums/showthread.php?t=265488
http://www.preludepower.com/forums/showthread.php?t=253704
http://www.preludepower.com/forums/showthread.php?t=275440
http://www.preludepower.com/forums/showthread.php?t=308500
http://hondaaccordforum.com/forum/showthread.php?t=3687

No Carb cleaner!! I think using can after can of carb cleaner to dissolve carbon in the egr ports is very hard on the O2 sensor and the Cat. So I carefully used bailing wire for cleaning out the tunnels between ports and the ports themselves. Also a drill bit works great for cleaning out the clogged egr ports. Only use the bit by hand!! Don’t use a drill motor!! This style of egr port cleaning resulted in zero smoke coming from the tail pipe. The car takes about 5 seconds more cranking time because the fuel rail is empty and unpressurized. The car ran great the instant it started.

Slide Hammers: Bondo makes two sizes of slide hammer. Get the larger of the two. I could not get some of the egr plugs out with the small slide hammer. In this pic, I used the larger weight on the smaller slide hammer. Just buy the larger slide hammer. You will need the right size drill bit for the sheet metal screws.

Warning!! The screws that come with the slide hammers are crap!! They break easily. The head diameter of the ones you buy at the hardware store are too large and have to be turned down to fit inside the slide hammer collet, but are stronger. Mine broke while screwing them into the egr plug. The hole I drilled was too small. Size it right.

Make sure your slide hammer has heads on the screws. The ones that came with the large slide hammer had no head on them. Usually they are a Phillips head.

Your hood: Don’t use the Honda prop rod to hold your hood up. Find something else to hold your hood far higher than normal. Otherwise when you pull out an egr plug you can dent the bottom of your hood when the plug suddenly pulls out, allowing the slide hammer handle to hit the hood. I was not using that much force to pull out the plugs and I hit the hood twice.

Clean out: Get a vacuum cleaner and adapt a 3/8 inch outside diameter hose to it with duct tape. This works great for vacuuming out drill filings and loose carbon deposits.

Here is how I had to get one of the egr valve nuts off. Not much room. A socket with a swivel would not fit either egr valve nut. A 12 point 12mm wrench with leverage was needed. I have the egr plugs installed already.

Someone had replaced the egr valve and it’s gasket once before. The manifold surface was sanded smooth. Just a quick vacuuming out of both holes and the egr valve port was done.

Here is what I used to clean the egr valve itself.

First apply vacuum to the egr valve, to lift the pintle off of it’s seat. This allows the carb cleaner to do it’s job better. Ooops! I just said carb cleaner! Yes, this is where I used a little carb cleaner. But blowing out the valve while it was open removed all of the carb cleaner. This is in line with my goal to better protect the o2 sensor and Cat from being fouled with carb cleaner.

Pull the vacuum pump off of the egr valve a few times as well. It will help clean the seat off while the seat is still wet with carb cleaner. Scrape off any old gasket material from the egr valve and it’s seat on the intake manifold.

Here is a home made broken screw extractor tool. It’s just a piece of aluminum drilled at both ends so the sheet metal screw that the slide hammer uses, will thread into this nicely. Then the slide hammer threads into the top of it. That way a broken screw can be removed at the same moment an egr plug is removed.

1) Let the car cool off over night. It also allows the fuel pressure to drop in the fuel rail so less is spewed all over the engine during disassembly.
2) Loosen or remove your gas cap.
3) Remove return fuel line and vacuum hose from fuel pressure regulator, on the end of the fuel rail.
4) Pull the PCV valve and hose out of the valve cover.
5) Remove the 3 bolts from the FITV valve. This allows room so that the fuel pressure regulator can be removed with the fuel rail.
6) Remove the two bolts with a 10mm socket that holds the fuel injector wiring harness to the fuel rail. Then remove the 3 nuts that hold the fuel rail to the intake manifold. Remove the IACV electrical connector. Leave the wiring harness in place, but pull it out of the way a little, and lift out the fuel rail. Carefully lay the fuel rail over to one side so it’s out of the way. Watch out for the ends of the injectors!

7) Remove the 2 bolts with a 12mm socket that hold the IACV in place. Leave the coolant hoses attached to both IACV and FITV.

8)Gently pull both valves out of position and use something like bailing wire to hold them out of the way. This gives needed clearance for the removal and installation of the port plugs.

9) Now it’s time to start removing the egr port plugs. Mine were aluminum. Some are brass. Both are easy to drill out. Make sure you have several drill bits available. Getting the hole the right size is important so that the screw from the slide hammer goes in snug but not so tight that you snap the head off. See my note above regarding which size of slide hammer to use for egr plug removal.

10) The egr port itself is just a hole in the bottom of each passage. Getting every spec of carbon out is just not neccessary. This car had 207,000 miles and the ports were still only half plugged. This pic shows one of them cleaned out and ready for new plugs. A piece of bailing wire with the 3/8″ long end bent 90 degrees, worked great to clear out the carbon buildup above and below the small hole. Bailing wire used between egr ports worked well too. A drill bit twisted by hand worked great for cleaning the carbon out of the small hole itself.

Using the 3/8″ outside diameter hose duct taped to my vacuum, worked great as removing the carbon deposits knocked loose with the bailing wire. This tube reached the aluminum shavings that found their way onto the top of the intake manifold.

Have your EGR port plugs and egr valve gasket ready to go.

I found that taking this old bolt and making a shoulder on it to fit the egr plug, held the plug in place much better when the hammer hit the bolt. I found that using a 3-5 lb sledge hammer gently, gave me better install control than a regular 1lb claw hammer with lots of muscle. The first couple of tries without this tool sent a couple of plugs flying.

The egr plugs I got from Honda were in fact steel. This is a parts magnet holding itself and a plug against a steel beam in my garage.

Reinstall the egr gasket, valve and nuts.

Inspect fuel injector ends to make sure you didn’t damage them or contaminate them.

Make sure the injector recesses on the fuel rail are clean!!!!

Carefully work the fuel rail back into position. It won’t just fall back into place.

Hand install the 3 fuel rail nuts. Leave them 1 turn loose.

Gently twist each fuel injector back and forth 1/8″ in each direction to seat the o-rings correctly. Mine leaked like a sieve until I did this.

Tighten the center nut first, then alternately tighten the end nuts on the fuel rail. This pattern helps the o-rings also seat well.

Bolt the injector wiring harness onto the fuel rail with the two bolts using a 10mm socket. Barely tighten them with your ratchet.

Now bolt the FITV and IACV back onto the intake manifold. Check that the o-rings are in place and are not contaminated. New o-rings are not a bad plan.

Reconnect the vacuum line and return fuel line back to the fuel pressure regulator.

Put the PCV valve back in place into the valve cover. Start the engine and use a flashlight to check for fuel leaks!

Note: The car will take several more seconds to start than normal since the fuel rail is empty and not pressurized. Plus the engine will miss a couple of beats for about 1 second.

Results: So far with 140 miles since the egr task was finished, pure perfection! The car no longer hesitates or bucks on acceleration. It might even idle a tiny bit smoother. Now I have to chase down the intermittent hard starting issue and the intermittent surging idle issue. I’ve started separate threads to cover these next two items.