Closing the EGR Valve *check first post for links*

[sierra]

Could the signal that closes the butterfly be altered so it's open wider across the range?
Say there was a set resistance that consumed the current to close it?

You might have guessed I know nothing about electronics.

[kingy]

Only just realised the other day i have had the plate on the wrong pipe this whole time . swap it to pipe A yesterday

[Longranger1]

I haven't got a wiring diagram to hand, but I think it is a 5 wire device i.e. 2 to actuate the servo motor and the others are the position sensors. Happy to be corrected, just a guess.

[sierra]

I haven't got a wiring diagram to hand, but I think it is a 5 wire device i.e. 2 to actuate the servo motor and the others are the position sensors. Happy to be corrected, just a guess.

I'll take that as a no.

[Longranger1]

Make that a 4 wire if my quick search is correct... The trouble is Sierra, is that there is a balance calculated between throttle valve closure and egr opening. You would have to match both up somehow so it doesn't throw a code. I reckon a 3/4" feed pipe to the exhaust gas cooler taken downstream of the intercooler and all would be sweet.

In other words, instead of exhaust gas, use intake charge air and leave the blank out so only fresh air can go through the egr valve. Of course it does mean that that exhaust has to be blocked elsewhere...

The thread that never ends...

[sierra]

The thread that never ends...

Yes but some bloody interesting ideas!
That would be an ironic solution, to feed in sweet fresh air so the whole complicated contraption achieves SFA!

[Longranger1]

You got it! A bit obvious but it would work a treat I reckon. All egr and emissions systems working perfectly to deliver clean, boosted and intercooled air. Bet there would be no codes generated either.

[chick_magnet_0001]

^^ love it,

im still keen to try what me and sierra were talking about, ill talk it over with the guys at teewah this weekend to see what they think.

[sierra]

:lol: ^^ love it,

im still keen to try what me and sierra were talking about, ill talk it over with the guys at teewah this weekend to see what they think.

That also allows a performance gain by controlling the MAP sensor.
It would be very helpful to know exactly what effect the air pressure to the sensor has on the fuel delivery to force it to give more fuel. I need some more fuel to go with the 20psi boost.
Did you find a good fitting for the hose?

[coxy47]

:lol: ^^ love it,

im still keen to try what me and sierra were talking about, ill talk it over with the guys at teewah this weekend to see what they think.

That also allows a performance gain by controlling the MAP sensor.
It would be very helpful to know exactly what effect the air pressure to the sensor has on the fuel delivery to force it to give more fuel. I need some more fuel to go with the 20psi boost.
Did you find a good fitting for the hose?

Im interested to know what the effect of the MAP sensory would be on the fuel delivery as well. I think the problem youll have with having an extra resistor in the circuit to widen the range the throttle stays open is that youll get same P0638 code that im getting now that appears to completely disable the throttle regardless of what you do until you either clear the code or turn the car off and back on again.

As for the throttle plug its a 5 wire plug - 2 for the servo and three for two Hall sensors that are wired in parallel (im sure someone will tell me if im wrong). The wiring diagram is below on the top right of the image. Im thinking if i create an open circuit across pin 4 it will disable the sensor and hopefully behave as if its disconnected.

[chick_magnet_0001]

my solution isn't electrical coxy well not "my" solution its just using information thats avaiable

[chick_magnet_0001]

re the hose: yess i have but it will need some work, ill get back to you on this when i have some spare time to work on it

[coxy47]

Ahh ok. Well i think ill either have an electrical solution by saturday or have dropped the idea completely so will be keen to hear any other suggestions

The only reason im pursuing the electrical method is im trying to make it as removable as possible.

[sierra]

Thanks for the wiring diagram Coxy. I might try to print that off before the printer gets packed away.
I'm assuming the MAP sensor governs the fuel according to pressure, more pressure = more fuel up the limit of the rail pressure set by the ECU?
That would explain the performance gain from plumbing in upstream of the throttle body where the pressure is higher and feeding some into the MAP sensor hose. The only problem with that and increasing the boost, is when you hit the fuel pressure limit governed by the ECU, then full throttle feels flat compared with the gains at part throttle as it runs out of the fuel it needs to complete the transformation.
So how can we fool the rail pressure sensor into thinking it has to supply more pressure without intercepting the signal with a chip?

[coxy47]

I was also under the MAP sensor governs the fuel input but judging by the effects of when the MAF sensor is dirty it must play a part as well.

The only other problem i can see with tricking the MAP sensor into reading higher is that wont it set off a limp mode if the reading exceeds around 21psi?? EDIT: Or i could just be misunderstanding what your talking about doing.

[sierra]

I was also under the MAP sensor governs the fuel input but judging by the effects of when the MAF sensor is dirty it must play a part as well.

The only other problem i can see with tricking the MAP sensor into reading higher is that wont it set off a limp mode if the reading exceeds around 21psi?? EDIT: Or i could just be misunderstanding what your talking about doing.

I think it was Tony? that plumbed the pressure from the other side of the throttle body into the MAP hose to the sensor.
He was trying to stop the low pressure code the EGR blank was causing and it worked. It also had the benefit of inproving
performance at part throttle and lower rpms I think it was? Since the butterfly seems to be operating a lot at lower throttle openings and the pressure after the EGR throttle is lower than before it, then just adding some of that extra pressure to the reading is enough to increase the fuel and performance. If you were to then restrict the flow from the normal hose before the 'T' that feeds in the higher pressure, you could increase that effect and the fuel by more.
Running a max 20psi boost must increase the fuel the same way but again, it tails off when you get anywhere near full throttle because there is no more fuel as the limit has already been reached.

[Tony]

Just a quick note here,

Any jiggery to the MAP sensor (Other than capping off top end voltage) will have a epic effect on the fuel metering and in the case of a MN the way the VGT works.

On a 3.2 if we tell it the boost is less across the entire range you get less fuel. More voltage will to some point increase the duration with out getting into the other players.

ON the 2.5 HP with electronic boost control, you also get less fuel to a point so wont boost up, then the turbo may run into over speed at a given tip point voltage out put from the MAP. Max fuel and VGT max boost thresh hold)
I have tried it.



I have actually found another way around this issue,(so simple its crazy) but feel like being cruel for a wile, see if you lot nut it out. I had to work it out so you will in time

Play nicely I want to see the thread make over 100 pages

[gregned]

Play nicely I want to see the tread make over 100 pages

Well ill play along I will see your tread and raise you a thread

[Tony]

What tread

[coxy47]

The other thought ive had to keeping the manifold at atmospheric pressure or higher is to fit a small shuttle valve to the sensor line so that if the manifold pressure drops below atmospheric it bleeds in normal air. My only thing with this solution is that im not sure it will fix my problem as the engine will still not be getting any more air at highway speeds so the fuel economy would still be crap

[RHKTriton]

What I've got at the moment (been a few months now) is the Wastegate actuator tee'd into the MAP hose, with the aim that pressure is kept high as much as possible. ie if Throttle closes during attempted EGR, the backpressure towards the intercooler doesn't cause the Turbo go off the boil. The next trick is to leave the WG actuator at the MAP port and run the MAP directly off the compressor port. This should take effects of throttle out of the game (if left normal) with protection of wastegate available. This is all 3.2 though.

[GLX-R Alex]

You may get weird pressure to the map affecting ecu calculations. I would imagine post intercooler map feed would be slightly different smoothed out reading. Straight off the compressor would be slightly higher and more erratic.

[coxy47]

Ok guys im looking for some advice from someone who has more electrical knowledge then I do as I have reached the limit of my skills as mech engineer.



Im looking at disabling the Throttle Position Sensor and am unsure which wire to create an open circuit across. Originally i was going to go for the black wire on pin 4 but just looking for some advice before i go cutting wires.

Cheers

[NTBB]

Would a 1 way check valve between the port and sensor work (+pressure would read -pressure would read 0)..

[chick_magnet_0001]

i thought it was a problem with it reading out of range, not just negative presure? but this is just my opinion you may of cracked it

Tony does NTBB get a star beside his name?