Official 420A EGR Block-off Disscussion 2007

[totaleclipse_05]

I think my EGR valve might be bad. When I have the vacuum line hooked up to it from the manifold and am cruising, it sounds and feels like it's misfiring almost. When I unhooked the vacuum line going to it, it ran perfectly fine.

 

[eclipsers-t]

Randy: Block off the head, so there is no exhaust leak. Leave the valve and the EGR tube in tact. Notch the surface of the EGR valve where it would mate with the head, OR drill holes into that chamber, or whatever. When the EGR opens, exhaust gas cannot enter the IM, because that side is blocked, but since we introduced a "leak" on the hot side of the valve, fresh air is drawn in instead. We need the fresh air coming in to prevent the idle from dropping when the ECU tests the EGR's flow.

I do not understand exactly what you are talking about here.

If you get rid of the cel, the ecu is going to think that the egr is running correctly, right?

If you block the egr off and remove the pipe for it, can you plug the sensor to the wiring plug to get the cel off?

 

[eclipsers-t]

I blocked my egr off when I rebuilt and I have Crower stage II turbo grind cams. I am having horrible vacuum/idle issues with no vacuum leaks.

Could the egr cause such on issue?

 

[Locke]

I do not understand exactly what you are talking about here.

If you get rid of the cel, the ecu is going to think that the egr is running correctly, right?

If you block the egr off and remove the pipe for it, can you plug the sensor to the wiring plug to get the cel off?

There are two codes that often annoy us because of a blocked off EGR. The P0403 "circuit open", which is easily remedied by leaving it plugged in, or wiring in a resistor. The other, more difficult to avoid code is the P0401 "insufficient flow" that occurs after the ECU tests for EGR flow.

Re-read driggs' post, hopefully it will make more sense now.

It helps to know how the system is tested before you can design a way around it. When the ECU closes the IAC and opens the EGR, it's looking for engine vacuum to draw in enough air to maintain idle through the exhaust post on the EGR. You get the CEL when you block this, as you seal the system off. When the ECU opens the EGR, the ECU sees the RPMs drop due to a blocked intake source.

 

[eclipsers-t]

Randy: Block off the head, so there is no exhaust leak. Leave the valve and the EGR tube in tact. Notch the surface of the EGR valve where it would mate with the head, OR drill holes into that chamber, or whatever. When the EGR opens, exhaust gas cannot enter the IM, because that side is blocked, but since we introduced a "leak" on the hot side of the valve, fresh air is drawn in instead. We need the fresh air coming in to prevent the idle from dropping when the ECU tests the EGR's flow.

I believe I understand what you are talking about here. You block off where the exhaust gases enter the EGR and leave the whole system plugged up. On the intake side you leave it open, but drill holes or notch the chamber so it can breath fresh air for vacuum?

And this helps aid in vacuum during idle!

 

[Locke]

Yes, except you want to make sure the holes, or notches or whatever, are on the side that attaches to the head. Otherwise you will just have an ordinary vacuum leak. We are looking for a vacuum leak that only happens when the computer tests the system.

 

[Locke]

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Just make sure the hole or notch is on the hot-side of the valve itself.

 

[eclipsers-t]

And I assume you have to hook up the vacuum line to the egr again?

Thanks Locke

 

[VelocitàPaola]

I sell them for $6 shipped

***

We have 420A cars, your 4G63 block-off kit won't work. Furthermore, there's no advertising in the technical forums!

 

[Locke]

And I assume you have to hook up the vacuum line to the egr again?

Thanks Locke

Yeah.

 

[eclipsers-t]

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Just make sure the hole or notch is on the hot-side of the valve itself.

Well, I took your advice. I drilled a hole in each side and notched the mating surface on two sides. It created more vacuum for me at idle and seems to be running better. It is really loud though. Sounds like a major leak. I probably should not have notched and drilled, but it is a little late now.

Thanks for the help!

 

[InfiniteGSX]

I'm still very confused on all of this...

im ordering an obx/venom style IM and I was planning on cuting my own blockoff plate for the head. But my main concerns are the Emissions... I have to do Emissions.

 

[totaleclipse_05]

I'm still confused about where you drill the hole in the egr piece.

 

[eclipsers-t]

If you look at the exhaust side of the egr valve (it looks like a blow off valve). You want to drill under the valve. Just like in Locke's picture.

 

[Locke]

The idea is to place a leak between the EGR valve and the head, not in a manner that hot exhaust gases can escape the head, but so clean air can be drawn in instead.


Here is another option that will do the same thing:

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You need one gasket and two block-off plates. Cut one block-off plate to create a good sized leak. (Green area in above pic is example of what should be removed. Green area was placed randomly in that pic.) Then assemble as follows:
Head -> Gasket -> Block-off Plate -> Hacked Block-off Plate -> EGR Valve

When the valve is closed, nothing happens. Exhaust will not leak because of the gasket and unhacked block-off plate. When the valve opens, it will draw clean air through the hole in the second block-off plate. (or through a hole drilled into the chamber under the valve, or the notched surface, or where ever we created a leak.)

Keep in mind, doing all this will also allow unfiltered air into the intake. Finding some manner to filter the air would be a good idea.

 

[totaleclipse_05]

So, instead of 2 blockoff plates, you could just take your EGR valve and, I guess, "cut out" a little section of the part that WOULD bolt onto the head so it can suck in some air? If that's what you are saying, I will probably give that a try if I throw a CEL. Haven't driven the car yet, besides moving it in and out of the garage, but I only have 1 plate sandwiched in between the head and EGR valve.

 

[Locke]

So, instead of 2 blockoff plates, you could just take your EGR valve and, I guess, "cut out" a little section of the part that WOULD bolt onto the head so it can suck in some air?

Yeah, exactly. Any which method mentioned will do the same thing.

Keep in mind that we are damaging the EGR when we do this. If it is faulty anyways, who cares. If you need to reverse it for any local emissions testing, the multiple plate method will be easier/cheaper to reverse.

 

[InfiniteGSX]

Ok, Little less confused... So... you block the head from the atmosphere... then you leave the entire EGR system connected to the intake manifold, but with a pretty big leak so it can suck in air...

I'm still trying to figure out how to pull this off with the new intake manifold. I was also hopeing to get rid of the entire EGR System... Unless I can figure out a way to fabricate it to be somewhere else...

Lets say just for the hell of it, can the EGR Valve be in complete open air? Meaning not bolted to the head at all and still work fine? If So I could possibly built something with the EGR Valve to act somewhat like a BOV... But I still dont see why we have to have it after we boost our cars. its just more of a boost leak if anything fails.

 

[XMasta19]

Here's an idea, don't waste your money on an obx intake manifold ...our stock ones are just fine. Is anyone else still confused? This seems to be a rather simple concept to grasp for me, but I have no problems lending my technical wording expertise if needed hehe.

Also the filtering of the incoming "leak" air should be quite easy. As long as you have the head side blocked correctly, you're not dealing with hot exhaust gases directly and something as random as a cutout of pantyhose over the plate should suffice.

 

[totaleclipse_05]

I bet if you put a bung on your new intake manifold and cut your egr pipe going to the stock one and ran a hose between the two, it could work. But yeah, I agree with X. Stock works just fine. If you want the shiny look, just polish the stock one.

 

[eclipsers-t]

Keep in mind, doing all this will also allow unfiltered air into the intake. Finding some manner to filter the air would be a good idea.

Has anyone found a way to do this?

 

[totaleclipse_05]

Has anyone found a way to do this?

I was just doing some thinking, and what if you could get a hole drilled in there big enough to fit a vacuum nipple on it (like just the part that the vacuum line goes over) and then route a vacuum line to the air intake pipe.

 

[mechanic606]

you can filter the air coming into the egr after you drill the hole or fix the block off plate.
i block mine off with a plate then took the egr and drilled a small hole right up through the base of the egr itself then tap it for a small nipple fitting, then ran me a vacum line from the nipple fitting to a nice little value cover filter or any other fitler you can fined to use works great and no dust. if you still have your factory breather box run your line from the fitting on the egr to the factory breather box.
thanks rick.

 

[eclipsers-t]

you can filter the air coming into the egr after you drill the hole or fix the block off plate.
i block mine off with a plate then took the egr and drilled a small hole right up through the base of the egr itself then tap it for a small nipple fitting, then ran me a vacum line from the nipple fitting to a nice little value cover filter or any other fitler you can fined to use works great and no dust. if you still have your factory breather box run your line from the fitting on the egr to the factory breather box.
thanks rick.

Do you have a picture? I am having troulbe understanding exactly what you are talking about.

 

[dr1665]

Do you have a picture? I am having troulbe understanding exactly what you are talking about.

He's talking about something like this for the EGR fitting, which is what I was suggesting in the first place. A couple years back, my buddy and I built a prototype of one of these active-blocked EGR set ups and installed it on his car. We used Locke's method. For filtration, we made our "sandwich" like this...

EGR
metal screen
plate with slot to atmosphere
solid plate (typical block-off plate)
HEAD

Remember, this system is only working some of the time and, unless you're super anal, your EGR pipe is filled with a sticky, greasy sludge which most dust is going to end up sticking to. Adding external fittings and hoses might draw attention from the smog people, so keep that in mind if you have emissions.