Cam position sensing w/o a cam sensor

James Montebello jamesm at lapuwali.com
Sun Nov 25 22:55:21 GMT 2001


A cam position sensor is used primarily because it is the least amount of
work, and the most reliable.  It's self-correcting every two engine
revolutions, so timing drift is pretty much impossible.  A simple
Hall-effect or VR sensor measuring a bolt on the cam sprocket is all you
need, and this is far simpler than trying to guess from an EGT probe.

The most reliable systems are simply interrupt-driven, reacting to
physical events in the engine.  The more periodic signals that are
actually connected to physical engine events you can provide, the better.
The more guesses from indirect measurements you make, the less reliable
the system.  

If there's a distributor drive present on your engine, you can use that
instead of the cam sensor, which might make mounting up a sensor easier.  

james montebello

On Sat, 24 Nov 2001, Santi Udomkesmalee wrote:

> I'm interested in running a sequential system, but I'm having a problem with 
> getting TDC of cyl. 1.  I know the traditional approach is to use a cam 
> sensor, but this seems like an excessive amount of work, since the ECM only 
> needs to sync the flywheel sensor input to the cam sensor input once.  My 
> thought is that the engine could run for a few seconds in batch fire until 
> the ECM could figure out TDC of Cyl. 1, and then switch to sequential.  If 
> anyone can figure out a way to do this cheaply w/o the use of a cam position 
> sensor, I'm open to any ideas.  I've thought about using an EGT in cyl. 1 
> exhaust tube, but I'm not sure if the EGT has a high enough resolution for 
> this to work.  Also, I've thought about using a peizo electric sensor for 
> sensing cylinder pressure on the spark plug 1, but I'm also not sure if that 
> will work.  Suggestions?? thanks.
> 
> -santi u.
> 
> _________________________________________________________________
> Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
> 
> ----- End of forwarded message from owner-diy_efi at diy-efi.org -----
> ----------------------------------------------------------------------------
> To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
> in the body of a message (not the subject) to majordomo at lists.diy-efi.org
> 
> 

----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org




More information about the Diy_efi mailing list