Sounds like you're on the right track... For any number of reasons, the
throttle plates are likely open too far. The extra fuel drawn from the
transfer slot will have things running on for Gawd knows how long. Lumpy
cams and vacuum leaks seem to the biggest causes of these. I have to add
that timing is usually a non-issue.... simply beause I have seen timing
blamed improperly too many times.
Remind us of your set-up and maybe we an help a bit more...
I know this is caused by a partially open throttle. But, is there a selonoid
on holleys that control this? I've also heard the fast idle screw could be
out too far??
Thanks Jim and "Crusty" :)
It's a 1980 Bronco with a 351M, Holley 4160.
And since I got ya.... :) ever since it got cold, anything below
say, -10C, in third gear (3-speed C6 auto), at anything under 50kph, even on
the slightest incline or when adding just the smallest amount of throttle,
it gears down into second. Thoughts on that?
Thanks again guys.
Here's a long shot for you.... Could either of the rubber hoses for the
vacuum modulator line be old and brittle??? This would give a vacuum leak
that might explain the after-run. And the high line pressures generated by
low modulator signal would give early downshift.
To be absolutely sure about the source of the after-run, I would pull the
carb (bring careful not to turn it upside down) and check the throttle
blades.... Above the little hole for idle feed on each primary is a slot
(transfer slot we call it). This transfer slot should not be visible with
the choke open and throttle closed (looking from the bottom. If you have a
fairly agressive cam, or any other problem that reduces the vacuum signal to
the carb, the first inclination is to open the throttles (using the
adjustment screw) to achieve idle... *most* times, this will give a highish,
"thready" (hard to find a good word) idle... sometimes seems like the change
from park or neutral to a gear drops the rpm a lot more than it should..
Tough for the old guy to describe after a frustrating evening with a
.go to your setup in outlook exp and set posting format for newsgroups to
text mode, non-html
I used to know about this... I had one car that had an anti-diesel
solenoid, it must have been a 73 LTD 351.
The idle stop screw was on that solenoid so that with key off, primary
plates were full closed.
Yeh, I'm a Krusty old Geezer, putting up with my 'smartass' is the price
you pay..DEAL with it!
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