Sleeper6's Gold 92GS Updated paint pics!

[Thefez]

After a bit of test driving my cel has still been bothering me with its egr code, this was my first attempt with a sensor removed from the old egr and taped at half mast, works brilliantly.. ..provided the motor is at proper temp above 4k so I still have some trouble shooting to do here and im open to ideas...

The reason for this is because, your creating a vacume leak with the EGR valve open at idel.. the egr valve only is suposed to open under cruse conditions to reduce NOx emmissons.. so at idel the engine doesn't know what to do with the unmetered air coming into the engine. hope this helps u understand more about whats going on if ya need more help let me know.

[Sleeper6]

After a bit of test driving my cel has still been bothering me with its egr code, this was my first attempt with a sensor removed from the old egr and taped at half mast, works brilliantly.. ..provided the motor is at proper temp above 4k so I still have some trouble shooting to do here and im open to ideas...

The reason for this is because, your creating a vacume leak with the EGR valve open at idel.. the egr valve only is suposed to open under cruse conditions to reduce NOx emmissons.. so at idel the engine doesn't know what to do with the unmetered air coming into the engine. hope this helps u understand more about whats going on if ya need more help let me know.

Actually yes, do you know any way I can leave it hooked up or wire in a pair of resistors to make it think its functioning properly all the time? I know is a 3 wire circuit I was thinking one pair of wires for one resistance and a second for the other wire

[Thefez]

After a bit of test driving my cel has still been bothering me with its egr code, this was my first attempt with a sensor removed from the old egr and taped at half mast, works brilliantly.. ..provided the motor is at proper temp above 4k so I still have some trouble shooting to do here and im open to ideas...

The reason for this is because, your creating a vacume leak with the EGR valve open at idel.. the egr valve only is suposed to open under cruse conditions to reduce NOx emmissons.. so at idel the engine doesn't know what to do with the unmetered air coming into the engine. hope this helps u understand more about whats going on if ya need more help let me know.

Actually yes, do you know any way I can leave it hooked up or wire in a pair of resistors to make it think its functioning properly all the time? I know is a 3 wire circuit I was thinking one pair of wires for one resistance and a second for the other wire

three wires sig, gnd, and 5v reff.. theres really no way to do that because multiple paramiters need to be met and seen by the PCM to activate it and deativate it.. baisicly you either need a new one or the correct one for the system to work proporly in this situation... hate to be there bearer of bad news..

[Nd4SpdSe]

Are you sure? The EGR has only 2 states, open and closed, correct? It wouldn't be too hard to trick it with a 5-pin relay and 2 resistors, connected to the line that the reference votage. When the ECU asks for a closed state, the circuit is closed with one resistor to content the ECU for the reference voltage of a closed EGR, and when the line is triggered for an open state, the relay is opened to use the other resistor with the value to send the ECU the voltage for an open EGR...

Could it not be that simple?

[Nd4SpdSe]

Are you sure? The EGR has only 2 states, open and closed, correct? It wouldn't be too hard to trick it with a 5-pin relay and 2 resistors, connected to the line that the reference votage. When the ECU asks for a closed state, the circuit is closed with one resistor to content the ECU for the reference voltage of a closed EGR, and when the line is triggered for an open state, the relay is opened to use the other resistor with the value to send the ECU the voltage for an open EGR...

Could it not be that simple?

[Sleeper6]

Are you sure? The EGR has only 2 states, open and closed, correct? It wouldn't be too hard to trick it with a 5-pin relay and 2 resistors, connected to the line that the reference votage. When the ECU asks for a closed state, the circuit is closed with one resistor to content the ECU for the reference voltage of a closed EGR, and when the line is triggered for an open state, the relay is opened to use the other resistor with the value to send the ECU the voltage for an open EGR...

Could it not be that simple?

See this is the kind of info I was hoping to find out, Any way you can think of to draft up a rough idea of how the circuit would work? Ill try to write one up and post it if you can let me know if it looks correct.

[davmac]

Nd4SpdSe is essentially right from the perspective of the ECM, but ...

The EGR is a vacuum operated valve. The connector at the EGR valve only sends valve position back to the ECM. To make the EGR valve move (under various engine conditions) the ECM sends outputs to the EGR vent solenoid and the EGR vacuum solenoid.

To fool the system you'd have to grab both solenoid outputs and depending on the states of those outputs send the proper position signal back through the EGR connector. It could be done, but I'd have to think harder about it and I'm not sure it is worth the effort.

Assuming you don't want the benefits of the EGR the easiest workaround would be to block off the exhaust gas flow, and hook up both vacuum and electrical to a working EGR valve.

[Sleeper6]

Assuming you don't want the benefits of the EGR the easiest workaround would be to block off the exhaust gas flow, and hook up both vacuum and electrical to a working EGR valve.

Yea this is what I am trying to avoid, if I wanted to have another valve and stream of vacuum lines bouncing around in my engine bay I would have just bolted the rotten thing on. Ild rather work out the electrical and hide a dummy fuse block under the dash to eliminate all that nonsense, that way I can still have feedback from the ecm for other essentials and keep the cel function.

[Sleeper6]

http://mx-3.com/manuals/showimg.php?fil ... F2-088.gif

Alright can someone explain the resistances to me in this circuit? I can wire and solder this up as needed but I dont understand how to read the required voltage, in particular what does the k(greek symbol) mean?

[davmac]

"k" is kilo = 1000
The other symbol is for Ohms (resistance).

The P/G (A) wire is the input to the ECU. The ECU is looking for a voltage that indicates the valve is open or closed.
I'm going to take a guess that the ECU doesn't read the position and throw a code unless it has requested the valve to open. When EGR is requested to be open the ECU expects to see 4.5 - 5.5vdc at the P/G wire. That means you could simulate the open position with the smaller resistor of 0.7 k ohms between LG/R (C) and P/G (A) wires at the EGR connector.

The B/BR (B) wire at the connector is ground. I'm not sure if that is grounded elsewhere and just connected to the EGR valve or if it gets its ground through the EGR valve. It wouldn't hurt to ground that wire.

That might be enough to fool the system.
If upon starting the car the ECU wants to see a closed EGR then you'll have to do something more sophisticated. I'm just hoping it doesn't throw a code if the EGR looks to be open at start up.

[Sleeper6]

yea its a two stage system that I will need to wire up a trigger switch to a relay to change the resistance. In the morning the light stays off till its warm then it comes back on at warm up, a fellow on PT was nice enough to start a diagram for me but thats been back burnered by a reoccuring oil pressure issue... You know what they say if you want it done right, do it your self. Motor build time for the lower end I pulled out to set some proper clearances

The link if your interested:
http://forums.probetalk.com/showthread.php?t=1701314642

[davmac]

I'm sorry to say that the FIS over on probetalk is confused.
VRIS solenoids are not involved in any way as far as controlling the EGR valve. No time for diagrams - and I'm not even sure I could put together a circuit, but here is how it works:

The EGR vent and EGR vacuum solenoids are ECU outputs that control the EGR valve.
When EGR vent solenoid is energized the EGR valve gets no vacuum and should be closed.
Resistance between A - C is approx. 5 kOhm
The ECU sees approx. 0.7V at line A (confirming the valve is closed).

When the EGR vacuum solenoid is energized and the EGR vent valve is NOT energized the EGR valve gets vacuum and should be open.
Resistance between A - C is 0.7 kOhm
The ECU sees approx. 4.7V at line A (confirming the EGR valve is open).

The EGR valve electrical connector is just connected to a valve position sensor which is equal to a potentiometer that changes resistance with the valve position. The C wire is constant approximately 5 Vdc control signal provided by the ECU. The B wire is constant ground. The A wire is input to the ECU and is a 0.7 - 5Vdc input depending on the valve position.

[Sleeper6]

egr experimentation is on a temporary hold. New motor has too much of a pressure drop for me to be comfortable with, pulling it out at the first of next month and dropping a wait for it.......


K8 back in

[Nd4SpdSe]

Are you sure? The EGR has only 2 states, open and closed, correct? It wouldn't be too hard to trick it with a 5-pin relay and 2 resistors, connected to the line that the reference votage. When the ECU asks for a closed state, the circuit is closed with one resistor to content the ECU for the reference voltage of a closed EGR, and when the line is triggered for an open state, the relay is opened to use the other resistor with the value to send the ECU the voltage for an open EGR...

Could it not be that simple?

See this is the kind of info I was hoping to find out, Any way you can think of to draft up a rough idea of how the circuit would work? Ill try to write one up and post it if you can let me know if it looks correct.

Oh, I completely forgot to do a follow up on this for ya' I dont visit here as often as I used to

I'll try to draft that up soonish.

[Sleeper6]

wow its been a hellish 2 weeks...

back on the 12th crazy winter snow storm in ny that took me out, my own fault running no timing covers and having to plow through 1' of snow combined with 3k on a manual tensioner an no readjust yet (silly me thinking I could wait till 4k for the oil change). Needless to say after two days of down time reset timing after spending the first day freezing out side diagnosing it and the second day trailering it to relatives garage to fix out of the weather.

Well come monday the oil pressure woes catch up to me and the lovely warning light of doom is actually flashing at red lights with my oil gauge pegging to zero at times, scary stuff. Nursed her to work and parked her for the week, called in a few favors and low and behold got an original low mileage k8 shipped to scrapyard just up the road from work. Funny thing about that, by the time I got to the yard to pick it up they had already put it in a core bin on top off 10 other engines getting ready to be crushed and it had only been there 4 hrs . Glad i didnt wait to pick it up. After all that, 2 late nights, new record of 10.5hrs to drop, swap exhaust/pulleys/intake/ecu/fuel rails and reassemble and roadtest.

End of story, she lives again. Now all i can do is ask how in the world I ever drove a k8, dont get me wrong Ill be glad for the fuel mileage but even with the headers/g4 intake shes soooo underpowered, but atleast shes running. Not many pics, working on the clock as I had limited time to used the shop and solo mio working on it straight. whew, anyone need spare K parts?