Hessitation in Late Model Subarus

[Don.F.Broadus at ucm.com]

Being a Pontiac Fan  I would like to hear more about your set up. I am
working on a 1973 400 Pont with a HEI right now and your system sounds
interesting.
                                          Thanks ,Don 

> -----Original Message-----
> From:	G. Scott Ponton [SMTP:gscottp at ix.netcom.com]
> Sent:	Saturday, May 08, 1999 12:41 PM
> To:	diy_efi at efi332.eng.ohio-state.edu
> Subject:	Re: Hessitation in Late Model Subarus
> 
> I have been following this thread for a while. There are other refferences
> to knock sensors and problems with "sensing" other engine noises in the
> arcives too. I have been running a old Pontiac with a custom distributor
> and
> ESC for several years (9). The engine has a solid grind cam and several
> other sources of "external" knocking. The only time I have ever had
> problems
> with the sensor picking up stray noises was went the oil pump drive broke.
> Although the rods weren't knocking audibly the ESC was retarding the
> timing.
>     I think Gary is right with his assumtion that the Subaru computer is
> "too sensitve". As I have never checked I am not sure but I would guess
> that
> the GM ESC/EST has a built in filter to eliminate certain freqs and
> amplitudes below a point.
>     When I first installed the system on this engine I was worried about
> the
> ESC retarding the timing because of the solid cam too. So I spent several
> hours with a 'scope checking the output from the sensor and checking to be
> sure the timing wasn't being retarded. The system worked/works perfectly.
> Now I can drive my old 11:1 pontiac anywhere on pump gas. Then if I want
> to
> race it I just fill it up with racing fuel and away I go.
> 
> Scott