confused please help!

philbert · Post by **philbert** » Fri Aug 22, 2008 6:54 pm

got the pulley machined and the sensor fitted just need to fathom out how to time it.
dont know if ive had a hard day or what but i cannot make any sense of this-

With the Engine at TDC for cylinder #1, the sensor should be positioned 'N' degrees after the missing tooth. Since the sensor wheel has a tooth (or the missing tooth) every 10 degrees, the sensor should be positioned N/10 teeth after the missing tooth (9 teeth after the missing tooth for 4 cylinder applications for example). Make sure you take into account the rotation of the engine: clockwise or counter-clockwise, when determining your sensor mounting.

The following graphic illustrates how the sensor position and missing tooth can vary relative to engine TDC- regardless of where the sensor is mounted, the missing tooth must be positioned accordingly.

its a four cylinder , clockwise rotation, and sitting at tdc.

philbert · Post by **philbert** » Fri Aug 22, 2008 7:25 pm

right then had cup of tea and a sit down and think!
as i understand it if the motor is at tdc then the missing tooth should be 9 teeth past the sensor is that right ?

Gilesy998 · Post by **Gilesy998** » Fri Aug 22, 2008 7:50 pm

That's correct.
The easiest way:
Mount the sensor in it's bracket, and turn the engine to exactlye TDC, stick the trigger wheel on the pulley with the missing tooth aligned with the sensor, then turn the trigger wheel 9 teeth in the engine's normal rotation. That is where it needs securing.

philbert · Post by **philbert** » Fri Aug 22, 2008 9:35 pm

Thanks

DannyP · Post by **DannyP** » Sat Aug 23, 2008 11:41 am

I believe if you do it that way, fix the triggerwheel to your pulley with the trailing edge of the tooth dead center on the sensor, like mine:

philbert · Post by **philbert** » Sun Aug 24, 2008 9:28 am

oh i thought it would be the middle of the tooth that should line up.
i took my reference from the middle of the missing tooth.
would this not be correct?

DannyP · Post by **DannyP** » Sun Aug 24, 2008 12:00 pm

The trigger wheel makes a pulse happen at the trailing edge of the tooth. I believe I am correct in this, but others can input about this.

MartinM · Post by **MartinM** » Thu Sep 04, 2008 1:25 pm

Definitely middle of the tooth....an exercise for the student to work out why from the graphs on http://www.bgsoflex.com/mjl/mjl_edis_summary.html

DannyP · Post by **DannyP** » Fri Sep 05, 2008 1:33 am

Martin, where you been, on vacation?

I thought I was right about that, but nobody corrected me, sorry. I guess my engine has 2.5 degrees more timing than on my map, then!

Am I right, a tooth and a gap equals ten degrees, so half the tooth should be about 2.5 degrees?

MartinM · Post by **MartinM** » Fri Sep 05, 2008 10:55 pm

Hi Danny

No - just busy stupid at work

Vacation actaully starts 6 weeks today - 2 months off, going round the world (China, HK, AUS, NZ and Fiji) with the current Mrs MartinM

Half a tooth = 2.5 degrees sounds spot on to me.....

Post by **brentp** » Fri Sep 05, 2008 11:08 pm

Martin, have a great trip, and be safe!