Re: Starts easily when cold, but won't idle when warm

[JOE FULTON <piper_pa20@xxxxxxxxxxx>]

Jerry,

You have a vacuum leak I think.  When the choke opens
the extra pulled in by the leak makes the mixture too
lean.  It won't idle when it is too lean.

Regards,
Joe Fulton


--- Jerry Phillips <jnpvegas@xxxxxxxxxxxxx> wrote:

> The engine ('68 390) starts fine when cold, but when
> the choke starts to come open, rpms start to drop
> and it is necessary to bump the throttle to keep it
> going.  The slowest it will run is about 1,200 rpm
> at steady throttle, anything slower and it stalls.
> 
> New:  Plugs, wires, coil, points, condenser, cap,
> battery cables, relay, relay to starter cable
> 
> Replaced: rebuilt Holley 4160 (vacuum secondary) 600
> cfm with electric choke
> 
> Timing at 5 degrees BTC, at 700-800 rpm in neutral.
> 
> I have tried it with the idle mixtures screws at one
> and one half turns out, as recommended in the Holley
> rebuild kit literature, up to three turns out as
> recommended on the Holley web site.  Doesn't seem to
> matter, it still stalls as the choke plate opens
> out.  As the engine warms up, the only thing that
> keeps it running is more gas.
> 
> Anyone got any ideas?
> 
> Thanks,
> 
> Jerry Phillips
> Las Vegas
> '68 AMX 390
> 
> 
> 
> 
> 
>