got it this time - egr bypass 606 turbo
 

Anyone interested??? I have been shown how to reconnect with the mothership.

I have probably 1,000 miles since the mod without any codes or performance decrease.

It takes a vacuum actuated electric switch, diode and one wire spice.

Joined the Epsilonian Confederation, did you?

I'm intrested. However, the thing I question tho is what is the gain? I see a lot of crud in the manifold and think that it is a combination of the oil vapors and the EGR. So elimiinating the EGR is one part of the equation. The other might be to eliminate the vapors. Any way to do both?

The crud is formed by the combination of soot and oil vapors from the ccv system. You only need to eliminate one of the two to prevent the crud from forming.

It's not nice to tease
 

I'm interested. Will have the intake off here in a few weeks changing the fuel lines, so I may have an official position as to my interest in actually doing the modification.

Don't just ASK if we want to know it. Of course we want to know. Just post it.

Like that avatar. Ku Klux Klan turbo huh? :D

Come on, you know it's Kühnle, Kopp & Kausch.

EDIT: Happy? there is an "&" in there now. :rolleyes:

Just yanking your chain

Post it! I have been trying to figure out how to kill the egr on a 606 for awhile!

ok, ok...
 

There has been just so much energy put into this one, I just had to post it that way. I did not mean to bring so much pain.

Yes, I did join the federation after much searching on the tdi forums.

Step 1 : Buy this device - Airtrol F4200-X30
Step 2 : Buy this diode from radio shack. I can not find the number. I will have to add it later.
Step 3 : Set the device to switch at about 19 or 20mm Hg
Step 4 : Snip the last number wire on the maf. It is number 5 or 6 depending on the maf used. Mine was yellow. I snipped it next to the computer under the plastic cover. Just make sure you have the proper one. Also the device fits neatly in there and it is quite obscure.
Step 5 : Hook top (com) terminal to wire to maf, hook middle (NC) terminal to diode, hook bottom (NO) terminal to other end of diode which also has the wire to the computer hooked to it. Just make sure the diode flow is going from NC terminal to NO terminal. All connections must be really good or soldered.
Step 6 : Hook vacuum hose that goes from solenoid to egr to the device instead.

When the computer sends vacuum via the solenoid to open the egr it will switch the device instead. The diode will create the necessary voltage drop that the computer is suppose to see from the maf. When not activated the circuit functions as normal.

Report back with success and/or questions. Good luck!!

I stopped by radio shack today to get the diode part number but they did not have the selection like the other store. I will get it posted within the next few days.

good luck! ;)

Radioshacks around here are all dropping their electronic components in favor of cheap toys and other electronic junk. You can buy stuff from Jameco (http://www.jameco.com), Digikey (http://www.digikey.com) or Mouser (http://www.mouser.com).

I don't know what their minimum orders are these days, but their component quality is much better than Radioshack.

The diode is IN4004 purchaseable at radio shack. Please report back with results. Failed or success. Sometimes it takes a little tweaking here and there but once you get it you are golden.

No CEL and I have logged over 2,000 miles.

Has anyone tried the mod yet???

I am finding setting the switch 20 or 21mmHg is more of what the computer is looking for to not throw a code.

Has anyone else successfully accomplished this mod?

This is interesting... Just read it for the first time. For the EGR, why not leave all the wiring and controls in place and simply fab up a blocking plate like we do for the TDI's and some of the trucks? This would allow the EGR to operate normally, just no gasses enter the intake.

As for the oil vapor, I'm experimenting with a Goldenrod fuel filter that I'm modifying into a condenser. I'm doing it first on my truck because the high boost causes crank case poo to ooze out of all of the joints in the intake system... Should work on the car as well.

Egr
 

That sounds like a great idea unless there is something that detects air flow through the EGR and rats to the computer if it doesn't see any.

Others have suggested plumbing the EGR valve to the air filter instead of the exhaust so that clean air goes into the intake instead of soot.

Jeremy

No that will trigger a code, we tried in on my friends turbo charged 606.

The air filter will bleed off boost, freaking the computer out.

The metal plate idea however might work, its probably worth a try.

I am scared to do this....do you have any pictures?

Turbo vs non-turbo
 

But it might work on the non-turbo 606 in the 96-97 models since there is no boost.

The blocking plate idea is even simpler. It would be easy to cut out a piece of aluminum and stick in there. If it worked (didn't throw codes) then it could be replaced with stainless steel.

Jeremy

That's what I've done on the TDI's - works like a charm and keeps the crud out of the intake. The computer commands the EGR, it does it's thing but there's no flow. I'm thinking that it would work on the MB unless the engine management system is significantly smarter.

I think it might work on the 606, heck if you want to try it give me your address and I will mail you a spare stainless steel plate I have. It fits the EGR on my 603 so it should fit yours. Slip it in and report back.

My friend already killed the EGR on his going this more complicated route.

You actually have a block off plate already cut to the right shape?

Yeah I pulled it off my 603, when I got one of Brians kits. His plate I buffed to a mirror finish, this one I couldn't because when it was stuck in between the EGR and manifold the exhuast gass's messed it up a bit. Now that the EGR is gone thats not a problem.

But its a cut to fit stainless plate, just need a gasket. I bet it fits the 606's EGR.

On the 606 turbo the computer must be fooled. There is no need for the blocking plate and it would not fit anyway. My girlfriend is traveling and she has the camera. I will see if I am able to get some pictures soon.

There is nothing to be afraid of. It is easy to put back to normal if you want.

Some pics would be a big help. I'd love to stop feeding crap to my engine. I guess cutting wires around the MAF makes me nervous. Don't want to replace one! I'm not sure I understand why the plate won't work. Can the computer detect lack of flow?

When the egr opens via the factory vacuum electric solenoid, the maf detects a .5 voltage drop which is read by the computer. This voltage drop must be simulated at the appropriate vacuum electric solenoid cycles to convince the computer everything is ok.

After 170,000 miles the crud on the inside of my engine was negligible.

Honestly, I don't know why anyone would bother with this mod. You're better off spending the money on having your injectors cleaned.

cutting wires at the ECU and MAF are kind of scary, I can't wait to get some pictures I have noticed some oily gobbily goop leaking out of my EGR, so gettign rid of it would be great.

I would be interested if you have a kit for my 606?

It is easy to snip the wire and solder it back if you want without complications.

I have to get the camera from my girlfriends brother because she is away. I should have it by the weekend.

I'm confused - I would think that normally open (NO) terminal would be connected to the diode anode and the NC terminal is connected to the cathode and the computer. This way when the sensor switches, the current flows out the NO terminal through the diode thus producing the voltage drop.

I know it is kind of confusing getting it all straight in the mind as it was for me. But I think once the vacuum switch switches, the flow is out the NC creating the voltage drop. When it is not switching it flows out the NO giving a normal voltage reading.

How many people have tried this so far with success? I believe Joe has but I am not sure?? Anyone else?

Having the switch set to the proper vacuum setting is the key!

I think I might give it a try as it sounds fairly simple. I like the thought of having my engine running on clean & cool boost - not to mention the elimination of caked soot in the intake manifold and cylinder heads. If it has the potential for reducing the probability of snapping a glow plug it's already worth the effort to me!

I like the idea of using a diode to reproduce the MAF voltage drop. I wonder if the 0.7V drop of a silicon diode is too high and requires getting the vacuum setting just right for no CEL - is the current too high for a germanium diode? Also, have you considered tapping the EGR transducer signal and do it 'pure electronically'? Not sure of the characteristics of these transducers but I'm up to experimenting...

I think .7 volt would work. If not just use the one I recommend. Tapping into the tranducer is out of the question. It is the signal the computer receives from the maf that is important. The tranducer just receives input from the computer and lets the computer know it is plugged in.

I think you are misunderstanding my response - I am suggesting that using the vacuum as an indicator to fool the MAF with a diode might also be accomplished purely with electrical modifications. Instead of the path 'electrical signal to EGR transducer to AirTrol vacuum sensor to diode inline with MAF', just do 'electrical signal to diode inline with MAF'.

I think I'll perform some experiments with the signals to the EGR transducer to see how the signal behaves. Once I get that info I should have enough information to draw up a circuit that should provide the same behavior on the MAF as your vacuum sensing setup. Customizing the K40 with an EGR on/off switch would be sweet.

I see what you are saying. You probably would have to use an electrical switch or relay. I am not sure how may volts output is at the tranducers but it is worth checking out.

I would think that would have been the easier route in the first place too.

After looking at the schematics I'm not sure it is going to be easier. Mapping the relationship between the EGR transducer signal and the MAF voltage should not be too bad.

I did learn more about the EGR mapping:

The exhaust gases are recirculated in line with the map stored in the IFI control module (N3/7) as soon as the following criteria are met:

* Coolant temperature between 60 °C and 110 °C
* Battery voltage 11 - 14 V
* Engine speed < 3000 rpm
* Fuel rack travel < 9 mm

I had it backwards - your posted circuit makes sense now.

I did some investigating on this last night and I found a couple things:

1. I located the wires in the box and I'll post a picture tonight or tomorrow night.

2. While monitoring the vacuum signal to the EGR, I noticed that it went away after the car warmed up and never activated again. This seems to represent a very small portion of time when the EGR is actually active.

3. The voltage drop/rise seems to be about 4/10 of a volt depending on where it's measured to. It was getting dark when I was doing this so I'll have to come up with better numbers later.

I think I'm going to pursue the use of a relay that puts the diode inline with the signal wire every time it gets energized by power from the EGR actuator/modulator.

If no one has a firm reason why this won't work, I may try it.

I am not sure if the relay thing will work. In theory it sounds fine and it takes the vacuum circuit out of it and makes it more direct. I guess the best thing to do is try it.

I do know for certain that the egr is active when the car is fully warmed up.

OK, I messed around with it this evening and came up with some more information.

After I got home, I checked the vacuum signal from the EGR solenoid and it is now functioning with the engine warmed up. When I pulled the electrical connector to test it, the computer instantly set a code. Whsn I re-connected the solenoid, it did not resume working so I figure what messed up my readings the other night was the fact that I had turned on the ignition with the MAF unhooked which set another code.

The EGR circuit never functioned again properly until the code cleared today.

The impedence of the EGR solenoid is 14 ohms. One thing I'm afraid of is that it is controlled by pulsed voltage which won't work for the relay. I'll give it a shot anyway but I may have to get an impedence matching resistor to make the relay mimick the EGR solenoid.

Here's a couple shots of the computer box with the MAF wires identified:

Overall shot. Notice the little yellow flags in the upper left and lower right corners. There are four of them.

http://i3.photobucket.com/albums/y71.../IMG_31161.jpg

Here's a closeup of the computer harness with three of the four flags visible.

http://i3.photobucket.com/albums/y71.../IMG_31171.jpg

Just an update,

I went out today and picked up the conponents at RS then breadboarded them into the correct circuit. I'll see if the ECU rejects the relay as a replacement for the EGR modulator this evening. If not, I'll move on to test the relay's action for the MAF.

Here's the circuit:

http://i3.photobucket.com/albums/y71...GRbypass-1.jpg

Another update:

I soldered the whole thing in place yesterday and I'm having a couple unrelated issues that may be effecting performance and tainting my test results.

1. After testing to see if substituting the relay for the EGR control would set a code, the vacuum line fell off of the wastegate controller setting another code.

2. I also got a "brake wear" indicator.

Right now, the ECU is allowing no or very little boost and when the throttle is floored, RPM's will climb to 4500 and stay there with the tranny seemingly stuck in that gear.

Will the CEL being on cause this condition and will it correct itself when the light goes out. Or, is there still some un-resolved code?

OK, on edit:

It's all better now... I left a vacuum hose off. DOH! :o

Success!
 

Codes cleared automatically on the drive home. Alpha testing is complete! I'll re-wire and tidy up the installation this weekend and begin beta testing.

Stay tuned... :)

That's awesome KarTech. I'm anxious to read the results.

Bump!

Success and the thread goes dead!

-Jim

Beta testing, still working a couple thousand miles later... Car's been off the road for a month now while I'm fixing various things related to age, mounts, brakes, etc...

I took a big leap of faith and totally removed the EGR tube and I'll be plugging the open ends with metal disks. I'll probably eventually open up the EGR valve and remove the restriction. I've gotten good at removing the intake manifold now - only like 5 min. especially with an air ratchet... :)

Here's a shot of the relay ready for installation:

http://i3.photobucket.com/albums/y71...s/IMG_3120.jpg

And one of the relay nestled in the box:

http://i3.photobucket.com/albums/y71...s/IMG_3124.jpg

Nice! Will any relay just work with if it has the schematic you posted? What diode did you use? I am looking forward to doing this myself and making it a cleaner installation.

I have removed the tubes and gutted the egr and plugged the ends already. It definately increases the airflow.