Substantial curb idle increase?
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Substantial curb idle increase?
Well I'm finally getting all my new radiator bugs
worked out, so I drove it a really good amount today.
Temps doing good, put shorter fan spacer in yesterday for fan/shroud
location. So I get home and throw it in park today and it's idleing like
choke fast idle?
Checked choke and fast idle cam, altitude dashpot has never been hooked up,
vac advance, everything seemed ok.
This morning when I knocked it off fast idle (manual choke) it ran as usual.
(kinda low rpms until total warm up) Drove it for about 15-20 miles here and there,
then I noticed this fast idle thing when I got back home.
It's not had decent rad in it for a long time.
Is it running so much better now that something has
flushed away and increased my idle?
Or something else?
It's really running and idleing good on the road.
Any thoughts appreciated!
73 F100 360 AT 2WD
worked out, so I drove it a really good amount today.
Temps doing good, put shorter fan spacer in yesterday for fan/shroud
location. So I get home and throw it in park today and it's idleing like
choke fast idle?
Checked choke and fast idle cam, altitude dashpot has never been hooked up,
vac advance, everything seemed ok.
This morning when I knocked it off fast idle (manual choke) it ran as usual.
(kinda low rpms until total warm up) Drove it for about 15-20 miles here and there,
then I noticed this fast idle thing when I got back home.
It's not had decent rad in it for a long time.
Is it running so much better now that something has
flushed away and increased my idle?
Or something else?
It's really running and idleing good on the road.
Any thoughts appreciated!
73 F100 360 AT 2WD
Posting Guru
Joined: May 2010
Posts: 1,867
Likes: 3
From: Alton, MO
Look for a temp controlled vac valve. It will be screwed into the intake manifold if you have any. If you have one trace the lines to verify they are good and connected. Use carb cleaner to check for a vac leak. Spray it where you want to check. Any change in rpm will indicate a vac leak.
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(I shoulda called this curve idle)
I took it to the store and checked my timing
and it was way high!
Maybe vac advance is stuck.
Few drops of oil?
What else could cause timing to
jump up?
EDIT
Well I just set it back where I had it
and it's doing fine. Thought I heard some
strange popping sounds after loosening dizzy
and moving it?
Possible dizzy bolt was just loose enough
to let it move from last time I set it.
OR messing with fan and shroud I bumped it.
It was at least ten degrees high. Roughly as high
as vac advance shoots it up.
Oh well...thinking about welding the hood shut!
lol
I took it to the store and checked my timing
and it was way high!
Maybe vac advance is stuck.
Few drops of oil?
What else could cause timing to
jump up?
EDIT
Well I just set it back where I had it
and it's doing fine. Thought I heard some
strange popping sounds after loosening dizzy
and moving it?
Possible dizzy bolt was just loose enough
to let it move from last time I set it.
OR messing with fan and shroud I bumped it.
It was at least ten degrees high. Roughly as high
as vac advance shoots it up.
Oh well...thinking about welding the hood shut!
lol
Cranky Old Guy
Joined: Mar 2008
Posts: 3,562
Likes: 6
From: Raphine, Virginia
Vacuum leak will increase idle, higher rpm makes timing read higher. Can you adjust idle back down with adjustment screw? You can eliminate vacuum advance as an issue by disconnecting and plugging at carb to see if things change, plus it needs unhooked and plugged to set timing anyway. Just a couple things to check.
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Thanks gfw
I had checked for leaks earlier and plugged
vac adv while checking timing.
Seems ok now and has restored some power even.
Running too good I think to be major vac leak.
Got myself convinced dizzy must have got bumped a little
what with battling the old rad, new rad, fan spacer, shrouds,
tstat, mechanical temp gauge sender, cutting core support hole
bigger and new hoses.
whew!
I had checked for leaks earlier and plugged
vac adv while checking timing.
Seems ok now and has restored some power even.
Running too good I think to be major vac leak.
Got myself convinced dizzy must have got bumped a little
what with battling the old rad, new rad, fan spacer, shrouds,
tstat, mechanical temp gauge sender, cutting core support hole
bigger and new hoses.
whew!
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