Jump to content
  • Welcome to 205GTIDrivers.com!

    Hello dear visitor! Feel free to browse but we invite you to register completely free of charge in order to enjoy the full functionality of the website.

Sign in to follow this  
86alexp

Xu9J4 Crank Sensor

Recommended Posts

86alexp

Sorry for yet another crank sensor post. I have searched the forum and google many times and I cannot find the definitive answer on the positioning of the Mi16 VR sensor.

I have found a few answers but they all seem different.

 

It is defiantly a 60-2 Wheel with 6deg between teeth and the consistent bit seems that, tooth #20 is under the sensor @TDC

 

For clarity am I right in saying at TDC the VR sensor is bang in the middle of the 20th tooth from the gap?

 

I have found all of these answers for VR sensor position: -

 

108 BTDC

114 BTDC

114,5 BTDC

117 BTDC

120 BTDC

 

Surely every Mi16 has to be the same for the OEM management to work?

 

I am guessing the variation in answers is from the way each different aftermarket ECU measures this

 

So in my case, for a DTA ECU the reference point tooth is the falling edge of the first tooth (#1) after the gap

If there are 114 degrees between tooth #1 and #20 and the trailing edge is ~1.5deg from the centre of the tooth

Therefore I come up with the reference point as 112.5deg BTDC for inputting into a DTA ECU

 

**Yet another different answer**

 

Would it be possible for someone with more experience and knowledge, to please try to answer or explain this issue definitively?

Share this post


Link to post
Share on other sites
86alexp

Hi Sam,

Yep my Mi16 knowledge is almost entirely second hand from PeterT's site :)

That gives physical TDC, I'm looking at the reference point of the VR sensor

Share this post


Link to post
Share on other sites
andy0075

"I am guessing the variation in answers is from the way each different aftermarket ECU measures this"

 

I think this is the correct answer :-)

 

You have to use an ignition timing light to get the correct figure for your setup.

 

I have a Megasquirt II + MI16 engine and i have 116°

Share this post


Link to post
Share on other sites
welshpug

I've got 117 degrees on DTA.

Share this post


Link to post
Share on other sites
petert

I thought it was approx 110 deg. I'm not sure exactly. The variations are caused by people's ability/inabilty to check their software timing with a timing light accurately. I use a tooth offset function in my software to push the number around closer to the maximum advance figure, so there's less time between the trigger and the actual event, making the engine more responsive. A lot can happen between 116 and 40deg BTDC. To be sure, lock your timing at 10 deg BTDC and verify with a timing light.

Share this post


Link to post
Share on other sites
welshpug

specifically it doesn't matter what angle you set it to as long as you aren't miles off, if you map to what the engine needs.

Share this post


Link to post
Share on other sites
86alexp

Great answers, thank you!

 

Just for my sanity.... @ TDC the VR sensor is in the middle of the 20th tooth from the gap?

Share this post


Link to post
Share on other sites
86alexp

I managed to power the ECU last night with the DTA Oscilloscope function. The sensor was detected as being about 112 Deg BTDC, but to confirm it with a timing light, which I will do as I have fitted the marker as PeterT suggests.

 

So to people using a DTA ECU I suspect 112.5 Deg BTDC looks like it may be right on the money.

Edited by 86alexp

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×