Closing the EGR Valve *check first post for links*

[coxy47]

The way to do it is to use the arduino to read the signal to the servo and use this to output the signal of the correct throttle position sensor to the ecu and output a separate signal to the throttle body servo to do what we want. The only difficult part is logging the signal that is applied to the servo and the corresponding signals of the TPS when the system is behaving as it should.

I was assuming that the temp or accelerator pedal reading would be 'changed' or frozen when it arrived at the throttle body, not before that.
Couldn't the arduino receive, say the temp signal and then pass on to the throttle body that the coolant is always 50c?

Unfortunately not. There are only 5 wires going to the throttle body. 2 to the servo and 3 for the TPS. This means there is no direct connection from the temp sensor or the acclerator pedal the the throttle body. The throttle body is controlled directly from the ecu and nothing else. So to control what the throttle body does you either have to control the servo directly through something like an arduino processor or reprogram the ecu to send a different signal under separate conditions.

Something like an MRT tune should be able to achieve this.

[coxy47]

Actually technically yes the arduino could intercept the signal and output it so that its only 50C but that would have to be output to the ecu, not the throttle body, and ultimately limits the ability to acurately read the temp sensor through the ecu and consequently the obdII guage and possibly the instrument cluster.

This would be most likely acceptable if you had a secondary temp reading and no adverse codes are generated.

[RHKTriton]

And the Saga continues.................

[coxy47]

Yep.

I cant ever see an end to this thread. Someone will always come up with a new and more creative way of solving the problem.

[sierra]

:lol: Yep.

I cant ever see an end to this thread. Someone will always come up with a new and more creative way of solving the problem.

We're getting close and the final solution will likely be very easy to carry out.

So the ECU sends a signal to the throttle body as a result of the info it got from the coolant temp sensor.
Why can't we take that signal and change it to the one we want the throttle body to receive?

[coxy47]

We're getting close and the final solution will likely be very easy to carry out.

So the ECU sends a signal to the throttle body as a result of the info it got from the coolant temp sensor.
Why can't we take that signal and change it to the one we want the throttle body to receive?

We can do this without a problem and this is the goal of the arduino processor. However to ensure that there are no problems we also need to intercept the signal from the TPS that is sent to the ecu and correct it to what the ecu is expecting to receive so we dont trigger a code.

So to sum it up, all signals to and from the throttle body must pass through the Arduino. Basically we take what the ECU is telling the throttle to do, ignore that and tell the throttle what we want it to do, ignore the signal that the TPS is outputting to the Arduino and then tell the ecu via the TPS wires that the throttle is doing what the ECU wants

Thus we get what we want and the ECU gets what it wants even though its a lie.

Same basic concept that an interceptor chip (i.e. Chip-it) works under just on a different part of the engine.

EDIT: Its necessary to modify the TPS output as well as the servo input signal otherwise you may as well just have the servo on a switch.

[irwazza]

And how much $$ is this fix going to cost approx?

[sierra]

I'm glad your girlfriend's dad is an electrical engineer.
Sounds like we just have to find a way to stop the TPS dobbing us in to the ECU?

[antoo]

So to sum it up, all signals to and from the throttle body must pass through the Arduino. Basically we take what the ECU is telling the throttle to do, ignore that and tell the throttle what we want it to do, ignore the signal that the TPS is outputting to the Arduino and then tell the ecu via the TPS wires that the throttle is doing what the ECU wants

It will be hard to always know what the ECU is expecting from the TPS position ... but it just occurred to me that perhaps the TBS position is relative to the EGR valve ... so could we (royal we) data log the relationship between the EGR valve position and the TPS position and then have a table that the arduino reads to know exactly what to send back to the ECU? The arduino could read on the fly the EGR valve position and based on that reading send back the dummy TPS position?

[Tim007]

I am going to ask Chip it if they have done any work on this that may save us some time. Given that the problem is exaggerated when the chip is on I would be surprised if they had not tried to correct it. Worth a phone call to Justin on Monday.

[coxy47]

So to sum it up, all signals to and from the throttle body must pass through the Arduino. Basically we take what the ECU is telling the throttle to do, ignore that and tell the throttle what we want it to do, ignore the signal that the TPS is outputting to the Arduino and then tell the ecu via the TPS wires that the throttle is doing what the ECU wants

It will be hard to always know what the ECU is expecting from the TPS position ... but it just occurred to me that perhaps the TBS position is relative to the EGR valve ... so could we (royal we) data log the relationship between the EGR valve position and the TPS position and then have a table that the arduino reads to know exactly what to send back to the ECU? The arduino could read on the fly the EGR valve position and based on that reading send back the dummy TPS position?

Possible but I don't believe they are directly related. It shouldn't be to bad to map the voltages for the servo as you only need the values for fully open, fully closed and 20% open.

The difficult part is mapping the output of the TPS and it's corresponding servo input values. But once again it shouldn't be too bad. Then it's just a bit of wiring and some logic based programming.

Arduino chips aren't expensive at all. Can pick them up quite cheap depending on the specific chip.

[sierra]

I am going to ask Chip it if they have done any work on this that may save us some time. Given that the problem is exaggerated when the chip is on I would be surprised if they had not tried to correct it. Worth a phone call to Justin on Monday.

Worth a call for sure.

I mentioned before[with some trepidation] the sprint booster and what reading the TPS was showing when that was fitted since it messes big time with the signal from the pedal to the ECU?

[coxy47]

I am going to ask Chip it if they have done any work on this that may save us some time. Given that the problem is exaggerated when the chip is on I would be surprised if they had not tried to correct it. Worth a phone call to Justin on Monday.

Worth a call for sure.

I mentioned before[with some trepidation] the sprint booster and what reading the TPS was showing when that was fitted since it messes big time with the signal from the pedal to the ECU?

My advice would be to flick Tony a pm rather then give chip it a call. But worth a try.

I don't see the sprintbooster affecting the tps that much other then how quickly it responds. Ultimately all it does is scale/amplify/speedup (not 100% sure on how it works) the accelerator pedal signal to the ecu so it should just change how quickly the throttle goes from 100% to 20%.

Just to clarify this isn't my idea its tsenior's so all credit from this should go to him. I'm just running with the concept

[s13tsilvia]

when installing the one way valve, which way does it need to be plumbed in? to allow air out or allow air in? looking at the pics it appears to be plumbed to let air in but i just want to be sure first?

[coxy47]

when installing the one way valve, which way does it need to be plumbed in? to allow air out or allow air in? looking at the pics it appears to be plumbed to let air in but i just want to be sure first?

Spot on mate. It needs to allow air in so that it can minimise the vacuum in the manifold.

[coxy47]

Heres the photos for those that are interested with where i spliced in switch to the TPS loom.

For the record i used the white wire on pin 2.

[biggibbo]

Need to be careful with the one way valves as it appears that not all are created equally.

This morning I had one let go at 110km going up Moooney on the F3. The ute went into full limp mode and I lost all power and almost got wiped out from behind. It showed up as P0299 underboost.

I had the spring type running for weeks no probs, however changed it to the flap type over the weekend after reports of the spring type sticking.

Well the flap let go and now flows frrely both ways, and has traces of oil inside.

All I can say is we need a more industrial type solution as the aquarium stuff just doesn't seem to cut it. Picture of the failed valve is below - Avoid these at all costs.

Scary $hit.

[Tony]

Your asking these aquarium leak back valves ratted at less than 1psi to hold upto 30psi, no wonder.

Glad you never got taken out.

Think I'll stick with the small hole in the TB for the moment. Reliable, invisible and effective.

I'm not sure how you go with any future warranty issues around the engine management any of you that chose to splice the loom on the TB. The misu technicians may notice.

[coxy47]

Your asking these aquarium leak back valves ratted at less than 1psi to hold upto 30psi, no wonder.

Glad you never got taken out.

Think I'll stick with the small hole in the TB for the moment. Reliable, invisible and effective.

I'm not sure how you go with any future warranty issues around the engine management any of you that chose to splice the loom on the TB. The misu technicians may notice.

They may notice but if it's repaired before it goes in for a warranty claim I'd like to see them prove we did anything detrimental other then possibly to the ecu or Throttle Body

[sierra]

Without a catch can[filter] the oil in the manifold must be eating these valves away. That does look a real cheapy but the better looking ones could be just as likely to fail with oil in them.
It either needs an an automotive/industrial quality valve that can handle oil and 25psi or it would be best to go another route until one can be sourced.

I had one or two limp modes running the chip and it's bad enough trying to get anywhere afterwards but i can imagine if it did it when you were overtaking it could be bad news.

Fitting something like a Provent 200 wont clean out the oil already in the system, especially in the intercooler, so that mist will keep coming for a long time.

The sooner we can fix the throttle body the better and if anyone has any doubts about the ability of the version of the valve they have fitted then I would remove it until a better fix is found.

[simonb]

Wow, that sounds scary.
What about a non return valve for pnematic circuits. Suppliers like SMC, Norgren, Festo will have industrial types which will handle large pressures and oil residue.

[biggibbo]

After thinking about what Tony said regarding PSI I asked the guys at work what they use on CO2 lines and they pointed me to the one way (non return) valve below.

They are used at up to 60PSI on our gas lines and experience temps anywhere from -12 up to 99 degrees depending on location and can handle gas and liquid.

They didn't have any handy, so they sent me up to the local home brew shop and hey presto $14 later all done.

Will monitor and report back if it all works OK.

[irwazza]

Festo and John Guest also make these fittings

[burnah]

They are used at up to 60PSI on our gas lines and experience temps anywhere from -12 up to 99 degrees depending on location and can handle gas and liquid.

Any idea what PSI is required to open them?

[Tim007]

So a bit more research today and I am 95% sure that disabling the the EGR valve will increase your fuel consumption as the valve is designed to create vortex airfow as the air passes over it. This affects to air fuel mix and give the motor is fuel efficiency. If you turn it off and it is open then you will not get that affect. That is also why it is noisy when not wide open as you can hear the air being bent over the valve. Essentially the same logic behind a Hi-Clone.