Dummy Sensors / Testing

[Mike Rolica]

You have to ground the ECM vats wire @ 30hz.  Use a npn transistor and drive
the ECM with a open collector.  You can verify that it is bypassed when you
get signal to the injectors (pulsing ground
Mike Rolica
EXT. 260
 :-)


	-----Original Message-----
	From:	Bob Valentine [SMTP:bob at tecmark.com]
	Sent:	Friday, October 15, 1999 10:41 PM
	To:	gmecm at efi332.eng.ohio-state.edu
	Subject:	Dummy Sensors / Testing

	I'm planning on doing a bench mockup of my system this weekend,
along with
	building a 555 VATS bypass (I've read the notes in the archives),
but a few
	questions before I get too far under way.   I'm hoping to get to the
point
	I can at least get it to kick the fuel pump, spin the distributor
and get
	the injectors to fire.  I've never had this ECM (165) running in a
car, so
	this sort of a basic life test. 

	1.  VATS bypass - is the signal "full wave", eg +2.5 / 0 / -2.5 ?

	2.  What's the easiest way to verify that the ECM is "alive" and
that I've
	bypassed the VATS?

	3.  I have a full engine sensor compliment, but none of the
emissions
	solenoids.  Will the ECM (for now) ignore these, or do I need to
present
	some sort of dummy load to it?    

	4.  On a '89 Firebird TPI schematic I have, the VSS input ("Speed
Input")
	is shown going to a "VSS Buffer".  What's this?

	If anyone's curious as to how I mounted the TPI throttle body to the
	intake, pictures are here ->  http://www.liii.com/~ravalent/tpi/ 

	The solid plate below the TPI has been drilled - got a gasket for
template
	today.





	--> Bob Valentine
	--> bob at tecmark.com