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ttv flywheel shenanigans

That flywheel would work well with a standalone EMS that is programmable, since it is 60-2 just not the same 60-2 as the volvo lh2.4 needs
 
I'd suggest exchanging the flywheel for the proper one designed for you car. You'll end up not having to spend money on an extra sensor and it's not optimal to start tuning a car that's not in perfect running condition. Yes you can still megasquirt it like it is, but it sounds like you're up in the air about megasquirting in the near future so don't back yourself into a hole now about an eventuality.
 
How can the signal be the same? If ups and downs are measured the t5 makes a signal

up->*insertmissingteethhere*>down and with the ops fw it should go
up>down*2missingteeth*>up>down..

Bobxyz pretty much answered this already, but here goes anyway:

4_1_triggerwheels.JPG


A VR sensor, a variable reluctance sensor, works on the principle of induction. Within the sensor there is a magnet and a coil of copper wire around it. This coil is the actual part that generates the signal.

When a tooth reaches the sensor this changes the magnetic field within the sensor. When the tooth leaves the sensor, this also changes the magnetic field. It is this changing magnetic field that generates the signal within the sensor by magic that is known as induction.

So a signal is generated whenever the magnetic field is changed.

On the picture we have two 4-1 -missing tooth trigger wheels. The other one has 3 actual teeth and 1 missing tooth. The other trigger wheel has 3 actual holes and one missing hole.

When the wheel rotates at the position where it is on the picture, nothing happens until the first tooth is reached on sensor 1 or when the first hole is reached on sensor 2.

Lets now imagine that the trigger wheels are rotating and the first tooth and the first hole are reached at the same time. This changes the magnetic field.

On sensor 1 the signal goes up in sensor lead A and it goes down in the same sensors signal lead B.

On sensor 2 this is reversed. The signal goes down on sensor lead A and it goes up in sensor lead B.

Each tooth gives a signal. Each hole gives a signal. Or rather, each rising edge of one tooth changes the magnetic field, and each falling edge of one tooth changes the magnetic field. Same goes for the holes: each falling edge of a hole changes the magnetic field and each rising edge of a hole changes the magnetic field.

The rising and falling edges are so close to one another that what you get is one up-and-down looking signal pattern on a scope (or one down-and-up).

On the "missing" -part there is no signal. So both of these sensor give 3 pulses and one flat spot on the signal. So in effect the signals are the same. They are mirror images of one another though. But if you reverse the polarity of the sensor 2, the signal becomes the same as that of sensor 1.

However, depending on how the trigger pattern is machined, there could be a slight shift of the signal, because rising and falling edges do not physically change place on the wheel when the sensor polarity is switched. This depends on how the missing part is done and on how the two different flywheels compare to one another. This can be fixed by moving the wheel or by moving the sensor.
 
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If you put a scope on the signal, regardless of which type of a 60-2 trigger wheel you have, you will see 58 peaks in the signal and then a flat spot.

1990 Volvo 240 CRANK SENSOR (idle):



wamtmh.jpg


CRANK SENSOR (incresed engine speed):

2duhztd.jpg
 
It might be issue that EZK doesn't like that level /zero crossing comes from wrong direction. Vipec ECU manual was quite amal that inductive CPS should rise first and then slope down to negative. B230 Lh pattern is different to white block, where that missing teeth section is void.

This started me thinking should I open that gap on B230 flywheel when using aftermarket ecu?
 
It might be issue that EZK doesn't like that level /zero crossing comes from wrong direction. Vipec ECU manual was quite amal that inductive CPS should rise first and then slope down to negative. B230 Lh pattern is different to white block, where that missing teeth section is void.

This started me thinking should I open that gap on B230 flywheel when using aftermarket ecu?

Yes, that's probably it.

dsc_0941p_658.jpg


Here is a picture i found online. It has a scope trace of both VR sensor signal lines on a 36-1 trigger wheel. The other is a mirror image of the other one. So if the engine management requires that the missing part is arrived from rising edge, but currently it is arrived from a falling edge, the problem should be fixable by switching the polarity of the sensor?

Of course that's not enough on its own, because each peak has now shifted a bit, so timing will be off. Either the wheel or the sensor needs to be moved, or some setting in ECU needs to be changed.
 
Did TS try to change polarity?

Volvo 800 series platform has the same issues. Volvo changed the sensor pattern from holes to studs somewhere 1997. Polarity change and done. No issues. Same goes for AT to MT conversions.
 
That's what I'm thinking, I don't need the stock crank sensor if I go megasquirt and use the yoshifab dsm adapter that goes in the block. That has a crank and cam signal.


Ideally you should persevere with getting the flywheel sensor working. Using a belt driven shaft for the crank position, be it cam or auxiliary shaft, is nothing like as accurate as using the crank. Using a belt driven shaft for cam position signal sourcing is fine, as it need not be particularly accurate as it just "forewarns" the ecu that the next missing teeth event shows it's TDC number one cylinder.

I go to some pains to add a proper crank position signal on RB26DETT Skyline engines, rather than the combination, cam driven, crank and cam position sensor assembly on thes belt driven DOHC engines.
sensor.jpg
 
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Took gearbox off, tried every which way to get TTV flywheel to work- no joy. Put dogdish back on - car runs sweet as a nut. Therefore, I think it's the TTV flywheel that will not work with LH 2.4. I think it's only fair that TTV get an invoice for the amount of time and expense it's cost me to basically get back to square one again.
 
Why dont you just call them to clear things up?!

Maybe you should also give them the link to this thread, so nobody will do the same mistake and they can change the article description?

When you handle this like a boss they may be fair and thankful to get you the right disc without charging you and never have this happen again...
 
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Yes, to be fair they have been quite fair. However they have still sent me an item not fit for purpose and I have pissed away a significant amount of time trying to get it to work. If they sort it out to my satisfaction then it's all good and I will report back. If they dick me about then I will report back too!
 
I swapped an automatic flexplate for a flywheel when I did a manual swap on my wagon, no affect on how it runs at all. But I forget what the 'special' section of the flexplate looked like. I think it was a solid block, not a long hole.
 
Have you double checked to make sure what you have received is definitely what you ordered? Mistakes can happen whenever humans are involved and it could be something as daft as someone picking the wrong part off the shelf or the wrong sticker going on a box.

Did you confirm with the company that what you were ordering was correct for your application and intended use? I've order the wrong bits before as a result of misreading or in some cases not reading the description properly.

The UK distance selling regs do state you are entitled to a refund if you have been supplied faulty goods or the incorrect item. If you have ordered the wrong part putto g your hands up and accepting this is more likely to result in you getting the right part in a short time frame with minimal additional hassle.

You are very, very unlikely to receive anything over and above what you have paid them, even if it is the sellers mistake, but your attitude will play a major part in how much any individual wants to help you. Call them. Be polite, and most of all treat them how you would like the be treated if the roles were reversed.
 
It could be so easy if ha had called a week ago or so... ^^

Considering he's in England, and it's a UK company, that should be a no brainer. Why he didn't do that BEFORE installing it is the part I don't understand. Cool to see all the geek input on farting around with the signal, though :-D
 
I think the term for OP is 'wanker'. Starts thread bitching about a part before contacting the maker. Here in the states we call it being a jerkoff.
 
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