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View Full Version : Adjustable Top Dead Centre sensor (from old site)



Ian S
23-02-2009, 23:22
<table border="0" cellpadding="0" cellspacing="0" width="100%"><tbody><tr valign="top"><td>Adjustable Top Dead Centre sensor.

contributed by Ian Simpson

Make your own, it's easier than you would think...

I made a TDC sensor adjustable today. I put it in the vice so that the plastic sensor body rested on the top of the jaws and one end of the metal bracket went through, but was not clamped in the jaws, just a loose but close fit. Then I got the big 8lb hammer and gently whacked the metal brackets other end and on the 3rd hit the metal moved a bit, through the plastic body. I nudged it right through revealing that the sensor body is held in place by it's plastic going through three of the small holes in the bracket. I pushed out the residual plastic from the three holes. Then moved the plastic body back to the centre. It's a firm fit so it'll likely stay where it's put. It looks like about ± 4° are made available on the bracket. This is achieved by moving the sensor, when fitted, towards the back of the car for advance or towards the front of the car for retard. However the gearbox may have metal around the sensors hole that may reduce this to perhaps ± 3°.

The hole squashed a bit on the bracket end I hit and I had to bend it so it was round again to get the bolt in. So it's probably best to leave the bolt in when whacking.

If the sensor moves too easily the bracket can have a slight bend put in to keep it in place.

Remember advancing the timing can lead to pinking and damage your engine. So use with care.

Sep 2003

Sparkie (http://www.rtoc.org/boards/../members/member.asp?memberid=1606)http://old.rtoc.org/chat/i/chatto.gif (http://javascript%3Cb%3E%3C/b%3E:chatto%28%271606%27%29) says:
some of the new sensors have an internal 'pip' in the metal to stop them moving. There are still the three bits of plastic going through the metal slider, but now there is an extra bit of metal right in the centre that doesn't allow the usual 'mallet' approach, you end up bending the metal slider....

So I Bought a Go-gas type torch from B&Q. Then clipped sensor part with mole grips. Then heated the metal slider until the very edge of the sensor plastic started to smoke and bubble a little. Then put the plastic sensor on a hard edge and tapped the metal slider so it comes all the way out. Then file off the metal lump and melted plastic. Should then be able to slide it back in to where it belongs.

Oct 2004

Ian S RTOC Profile (http://www.rtoc.org/boards/member.php?u=5) http://www.rtoc.org/boards/images/buttons/sendtofriend-small.gif (http://www.rtoc.org/boards/pm.php?do=newpm&u=5) </td> <td width="15"> </td> <td width="200"> http://old.rtoc.org/articles/i/autofolder/YXAGNQTMWATJTZFFXSRE_t2003_9_23_15_40_57_q60_f14_1 50x126.jpg (http://old.rtoc.org/articles/i/autofolder/YXAGNQTMWATJTZFFXSRE.jpg)

TDC sensor
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