DIY_EFI Digest V3 #445

[Joe Boucher]

I learned a lot about the VSS and the speed sensor in the tail of my 700R4 when I
converted my '81 Suburban.  I used an '89 TBI.  The speed sensor in the tranny feeds
the AC signal into a circuit of some kind in the instrument cluster.  The circuit
converts this into an on/off 12 volt signal which is then fed to the ecm and the cruise
control.  So the signal used by the computer is a square wave.  Feeding a 2000 pulse
into the computer would give the computer a half speed input.  Is that better than
nothing?

Joe Boucher
'70 RS/SS Camaro  '81 TBI Suburban




> From: mrvette <mrvette at bellsouth.net>
> Date: Mon, 28 Sep 1998 19:06:46 -0400
> Subject: Re: VSS importance
>
> I hope your flip-flops work guys,  but I was told by someone in the know, that
> the computer as part of it's failure analysis capabilitites will recognize only
> a sine wave input......hope he's wrong,  but I don't think so....I ran my 7730
> computer in my vette 350, direct port inj.  and only had the idle variation
> problem, from lack of VSS signal....that is why I bought the right sender when I
> knew that was the last difficulty....GENE