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Author Topic: Crank Signal  (Read 7166 times)
Rabbid
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« on: February 18, 2014, 10:17:28 AM »

Hi

Has anyone ever used a Bosch ME7 ECU and replaced the engine bottom end with another one and been able to configure the crank signal properly so the tooth gap is properly aligned to TDC. I have a feeling that these sensors are going to be at different angles on the block in relation to the pickup from the old engine to the new engine.

Basically we're fitting a 1.6 engined car with a 2.0 block, the alternative is to use an external trigger wheel and then run it that way. But it would be cool to make use of the existing trigger wheel and crank sensor.

I have a feeling the tooth gap on the wheel is exactly at TDC of cylinder 1 and therefore in new engine the crank sensor sits about 30-45 degrees clockwise from this, but in the old engine it sits about 30-45 degrees anti clockwise from TDC so timing would be incorrect.

I imagine there must be an offset angle SYS Constant value but I don't believe these appear in the Damos files I have for this ECU.

Has anyone attempted this before?

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adam-
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« Reply #1 on: February 18, 2014, 10:53:44 AM »

This is similar to my first post here.  Fitted a 6n2 Polo (with a trigger wheel), with an AFH engine on bike carbs.

Wanted to utilise the crank wheel so I could use the ECU purely for the ignition control, adapt a MAP sensor on the manifold, and possibly knock sensor.

The Polo ring had a pin hole in it, that were locked off with a special VW tool.

http://www.clubgti.com/showthread.php?224958-OEM-crank-sensor
http://www.myturbodiesel.com/1000q/a5/Rear-main-seal-Jetta-Golf-mk5.htm
http://www.motorgeek.com/viewtopic.php?f=10&t=45986

These are external though, and were mounted on the flywheel seal end.  Yours is possibly on the crank, although not sure.

Can you not reposition the new ring to match the position of the old one?
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ABCD
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« Reply #2 on: February 18, 2014, 08:06:41 PM »

Hi

Has anyone ever used a Bosch ME7 ECU and replaced the engine bottom end with another one and been able to configure the crank signal properly so the tooth gap is properly aligned to TDC. I have a feeling that these sensors are going to be at different angles on the block in relation to the pickup from the old engine to the new engine.

Basically we're fitting a 1.6 engined car with a 2.0 block, the alternative is to use an external trigger wheel and then run it that way. But it would be cool to make use of the existing trigger wheel and crank sensor.

I have a feeling the tooth gap on the wheel is exactly at TDC of cylinder 1 and therefore in new engine the crank sensor sits about 30-45 degrees clockwise from this, but in the old engine it sits about 30-45 degrees anti clockwise from TDC so timing would be incorrect.

I imagine there must be an offset angle SYS Constant value but I don't believe these appear in the Damos files I have for this ECU.

Has anyone attempted this before?



There is a system constant SYS_GRNDWRT which is hardcoded and specifies pick up coil position from missing tooth when the piston is at TDC.

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Rabbid
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« Reply #3 on: February 19, 2014, 05:08:27 AM »

None of my DAMOS's include the SYS variables it seems.

We have about 30 degrees difference in the crank sensor positions. The new engine is wheel on the crank and sensor mounted in the block so we cannot move it.
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Rabbid
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« Reply #4 on: February 19, 2014, 05:54:40 AM »

Using ASAP2 viewer I can see the system constants the values are included in the damos, but it doesn't tell me locations.

I'm guessing this value is hard coded in the code at compile time and not stored in a memory location so every usage will need replacing?

108 degrees comes in roughly what we looked at by looking at the crank wheel.
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adam-
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« Reply #5 on: February 19, 2014, 08:18:55 AM »

What engine are you using?

The 2.0 TSI from the 2004> Golf uses a trigger wheel bolted to the crank, I've never seen one that's PART of the crank itself.

Either that, or machine the ring down say, 10mm, then place a new ring that fits over the top, and tack weld in place, using your required degrees shift?
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Rabbid
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« Reply #6 on: February 19, 2014, 09:20:25 AM »

This is Vauxhall stuff all ME7 though.
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Rabbid
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« Reply #7 on: February 19, 2014, 10:31:24 AM »

Right we've got a crank signal now cause we can smell fuel injecting.

We've done our calculations of the sensor to TDC difference and its 18 degrees more advanced on this ECU vs the engine.

So do we retard all the maps 18 degrees or do we try and find the constant is the next question..
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NOTORIOUS VR
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« Reply #8 on: February 20, 2014, 06:48:12 AM »

Each tooth you're off on the crank trigger (60-2) is 6 degrees.

360deg / 60 teeth - 6 deg per tooth

it's a more precise way to tell how many crank degrees you're off.
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Rabbid
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« Reply #9 on: February 20, 2014, 01:52:41 PM »

Yep we've done the maths based upon the actual pick up wheels in the engines to check the sensor to TDC angle.

One of the engines ECU's I have an A2L from and can confirm the 108 degrees is correct in that.
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catbed
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« Reply #10 on: February 21, 2014, 09:52:29 PM »

SYS constants are used at the time of compiling like you have said. You will not find them in the file itself.
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Rabbid
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« Reply #11 on: February 22, 2014, 12:58:48 PM »

It looks as if there is a phase adaption table that can be adjusted to adjust the final ignition angle.

Worth a shot, but otherwise back to the ASM and trying to find every single reference to the constant lol
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