Thanks,

I'm pretty sure that the MAF is just used in conjunction with the EGR for validation purposes. I've been thinking about MAF elimination to go with the EGR delete. My theory is to use a device called a programable voltage regulator (LM317, T0220 case) to supply the ECU with an average voltage in place of the MAF. This theory depends on the ECU not looking for a particular voltage range based on RPMs.

The EGR feed can also be used to modify the output of the LM317 and simulate the effect of the EGR delete circuit.

I'm kind of burnt out on this right now so I'm just going to leave the car as is right now and see how it responds for the next couple weeks. It did well today and now that I have a Scangauge II, I can R&D the circuits about 10 times faster because I can reset codes instantly.

Stay tuned...

Great that we are thinking on the same lines. You have been quite the work horse and mind behind this stuff. I know I and everyone else appreciates it!

Relax, enjoy and rejuvenate! Staying tuned...

Nice work! I have not been visiting this forum in a while and I sure missed some great stuff. Never did take the plunge and try the vacuum solution posted by mdisav - I'm definitely 'in' on the electrical solution that KarTek is crafting...

I have the whole month of April off as I am between contracts at the moment. Let me know if there is any way I can help. I have access to an electrical engineering 'guru' that would definitely help out.

Any update on the setting for that variable resistor?

Scott,

Here's the schematic of the circuit I'm running right now:

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

It's been running fine with no codes for over a month now of daily driving in a variety of environmental conditions.

97 NA help?
 

Evan,

Could you give a bit of info to help those of us with the '97 normally asperated engines figure this out? I was able to follow your instructions till I got to the part about the MAF pin 5. The EGR would no longer open but then it set a code for EGR flow. Guess it was looking for the response to the pressure drop. The 97 has a MAP sensor and an electrical connection on top of the EGR valve.

Also, I tried making a block off plate for the EGR but it sets a code. The U.S. version of the 97 has the electrical connector on top of the EGR so is not like the UK version.

Any help would be greatly apprectiated!! Let me know if you want a pic of the EGR or anything.

Thanks,
Louie

For our '97 E300's you don't to do anything like on the turbo motors. What I have done and is disconnect the metal pipe going from the manifold, to the EGR and flipped it 180. The longer portion of the pipe is directed toward the firewall with a valve cover breather installed at the end. The shorter end can be mounted back onto the EGR valve. No CEL's. Everything still works as designed. Just need to make a blocking plate for the hole coming off of the manifold. I used a copper pipe end, flattened it and trimmed it to fit.

'97 does NOT have a MAF.

On another forum I saw a MB part number for a blocking plate for the 606.91x.

Didnt pay too much attention to it but Mich. might have saved the link to the thread?

Here it is...


EGR Block-plate | OM606/605/604? non-turbo

The blcking plate did not work on mine. It still throws a code. I guess I can try the breather cap on the end of the tube but it makes me uneasy to think that you are sucking in air that is not filtered very well. Face it, an air cleaner element filters much more than some steel wool type stuff in one of those breather caps. Crankcase ventilation is a different animal.

With those concerns in mind, I was hoping tha Kar Tek could give a little guidance on how to figure out the '97s system so it could be eliminated like his turbo version was.

Why not put a hose fitting on the air box and run the tube to it?

Nice idea, that is a great option!

Thanks :)

I wish I could help but I've never laid hands on a '97 (other than a quick look) I'm sure the computer is just looking for a contact closure on the EGR mounted switch when a vacuum signal is sent to it but that's just guessing on my part...

I'm confused as to why the solution discussed in Micha's thread will not work for you since you both have the same car... :confused:

One other thing, I'm sure F'd I is talking about a tube from the INLET side of the EGR (the exhaust connection) rather than hooking the outlet into the airbox which would route exhaust into the air box... :eek:

First of all, thanks for responding. The reason the blocking plate worked for the '97 in that thread is the European version must be different. The egr simply has a vacuum pot on top of the egr (like my '95 does). The U.S. version of the '97has the electrical connection on top of the egr.

The connection on the egr has 3 wires. Maybe you could steer me in the right direction as to what kind of signal I would be looking for and under what conditions. When I installed the resistor, diode, and pot, the egr wasn't opening but it soon threw a code and must have put it into limp home mode cause it ran poorly and didn't shift correctly trying to do an "Italian Tuneup."
It also has a MAP sensor. Would that be a factor?

I could take pictures if that would help.

The solution of going to the air box should work but would certainly not look stock:(

Thanks to everyone for trying to help!

Just installed Evan's EGR 'bypass test' circuit and it works great - no codes after a short test drive.

I wanted to make my modification such that it can be easily removable so I decided on using taps on the ECM wires since the circuit does not require these to be cut (see egr1.jpg attachment). I used a small PCB to build the circuit and used some spade terminals leads to the wire taps. The board is small enough to wedge into the empty F7 fuse slot on K40/4 so no need to let it float around (see egr2.jpg attachment).

One note to others who might try this circuit: The wire colors to the ECM are NOT unique to each connection - make sure you've tapped the leads on pins 21 & 35 by ringing them out once the wire taps are on (I've attached the N3/7 connector diagram). Also, make sure to unplug the EGR vacuum transducer since that load is simulated in the circuit.

Thanks again Evan - if your planning on moving on to modifying MAF and/or MAP sensor readings for handling a bigger turbo count me in to help out where I can...

Sounds great Scott! Nice job using the taps, that's a good idea. One thing I would suggest is to dip/brush your circuit with liquid electrical tape to seal it in and insulate it from moisture and vibration.

If I move on to the MAF, I'll keep you up to date with that progress as well.

Louie,

To get started, you should reverse any wiring you've done to try to duplicate the turbo EGR circuit. Once you do this, we'll get started trying to figure out a system that will work for you.