On a moderately built 305 with a Performer EPS intake manifold . This
thing runs like a scalded cat , did everything I wanted - except idle .
No matter what I did it would idle for a few seconds then just stumble
and die . Turns out that the spacer under the carb was the problem . I
had to use a spacer in order to have a vacuum port for the brake booster
since this carb doesn't have a port on the back . Turns out that because
the spacer is open without a center rib (and the manifold has one) it
causes problems with the idle circuits . The solution turned out to be
getting a spacer that has 4 holes instead of the open one . The new
spacer didn't have a vacuum port ... but it had enough meat to drill and
tap for one . And now the truck idles in gear without dying . I haven't
driven it yet to see if it runs differently on the road , but I don't
expect any significant change in performance .
--
Snag
"They may take our lives but
they'll never take our freedom."
William Wallace

Snag wrote:
>   On a moderately built 305 with a Performer EPS intake manifold . This
> thing runs like a scalded cat , did everything I wanted - except idle .
> No matter what I did it would idle for a few seconds then just stumble
> and die . Turns out that the spacer under the carb was the problem . I
> had to use a spacer in order to have a vacuum port for the brake booster
> since this carb doesn't have a port on the back . Turns out that because
> the spacer is open without a center rib (and the manifold has one) it
> causes problems with the idle circuits . The solution turned out to be
> getting a spacer that has 4 holes instead of the open one . The new
> spacer didn't have a vacuum port ... but it had enough meat to drill and
> tap for one . And now the truck idles in gear without dying . I haven't
> driven it yet to see if it runs differently on the road , but I don't
> expect any significant change in performance .

Great bit of detective work!

On 4/3/2024 5:29 PM, Paul in Houston TX wrote:
> Snag wrote:
>>    On a moderately built 305 with a Performer EPS intake manifold .
>> This thing runs like a scalded cat , did everything I wanted - except
>> idle . No matter what I did it would idle for a few seconds then just
>> stumble and die . Turns out that the spacer under the carb was the
>> problem . I had to use a spacer in order to have a vacuum port for the
>> brake booster since this carb doesn't have a port on the back . Turns
>> out that because the spacer is open without a center rib (and the
>> manifold has one) it causes problems with the idle circuits . The
>> solution turned out to be getting a spacer that has 4 holes instead of
>> the open one . The new spacer didn't have a vacuum port ... but it had
>> enough meat to drill and tap for one . And now the truck idles in gear
>> without dying . I haven't driven it yet to see if it runs differently
>> on the road , but I don't expect any significant change in performance .
>
> Great bit of detective work!
>

Not my detective work though . The credit goes to a friend who has
more experience with performance mods . I've maintained all our vehicles
over the years , but this is pretty much my first foray into performance
mods . And likely my last considering I'm no spring chicken anymore .
--
Snag
"They may take our lives but
they'll never take our freedom."
William Wallace

Snag wrote:
> On 4/3/2024 5:29 PM, Paul in Houston TX wrote:
>> Snag wrote:
>>>    On a moderately built 305 with a Performer EPS intake manifold .
>>> This thing runs like a scalded cat , did everything I wanted - except
>>> idle . No matter what I did it would idle for a few seconds then just
>>> stumble and die . Turns out that the spacer under the carb was the
>>> problem . I had to use a spacer in order to have a vacuum port for
>>> the brake booster since this carb doesn't have a port on the back .
>>> Turns out that because the spacer is open without a center rib (and
>>> the manifold has one) it causes problems with the idle circuits . The
>>> solution turned out to be getting a spacer that has 4 holes instead
>>> of the open one . The new spacer didn't have a vacuum port ... but it
>>> had enough meat to drill and tap for one . And now the truck idles in
>>> gear without dying . I haven't driven it yet to see if it runs
>>> differently on the road , but I don't expect any significant change
>>> in performance .
>>
>> Great bit of detective work!
>>
>
>   Not my detective work though . The credit goes to a friend who has
> more experience with performance mods . I've maintained all our vehicles
> over the years , but this is pretty much my first foray into performance
> mods . And likely my last considering I'm no spring chicken anymore .

I know the feeling.