Carb troubles

[78F250SCCS]

I still have high idle. I adjusted the idle screw,but that doesn't seem to help. Looking at the carb from the side it looks like the throttle should be resting against( I don't know the part name) the thingy.

You can see the gap, and when I pull the throttle towards the "thingy" the engine idles down. When I let go it springs back about a 1/4" and the engine goes back to high idle. Is that 1/4" gap normal. I have no clue and just want to know more about the carb.

 

[LEB Ben]

So you adjusted the idle screw and there was absolutely no change...in either direction??? Even with a 1/4 turn you should be able to hear an audible change. Are your springs aligned properly, and not weak? And is it possible your rig's timing is advanced farther than you think?

 

[78F250SCCS]

Ya, I turned my idle screw down, back to the OP and then up and the idle pretty much stayed the same. Its like the throttle is just stuck there. I'll have to recheck the timing. What is the purpose of the part in front of the throttle.

 

[Alvin in AZ]

Cool picture taking, thanks for the back drop.

Off hand it's tough for me to image what could cause the symptoms you
described. Unless it's the choke adjustment doing that. This is something
you're just going to have to figure out, you can do it.

How does the idle (and its throttle stop) act after it's fully warmed up?

I just downloaded a .pdf file the other day... I'm not sure it was being
distributed legally. LOL I'll copy it to my "etc" webpage...

http://www.panix.com/~alvinj/etc/2100&2150.pdf

Dennis, you got a copy of that?
I haven't read it all yet. :/
Too much choke crap!

Alvin in AZ

 

[Alvin in AZ]

What is the purpose of the part in front of the throttle.

Well there were two things that looked kind of alike to me anyway.
One was an anti-dieseling solenoid that'd let the throttle close real
tight when the key was turned off. The other was a throttle stop
that would hold the throttle open a little bit wider when the A/C
was turned on.

Alvin in AZ
ps- Where you at? Fill out your stuff. Don't be so lazy.
Your carburetor looks better than what's in the .pdf file.

 

[78F250SCCS]

Thanks Alvin. I tried to loosen the distributor but it wouldn't budge. I have to spray it with some release all.

 

[Mil1ion]

Before setting the carb there is bunch of mechanical things that need to be set properly first.

There is great thread on this site explaining the whole procedure from scratch,
I think the thread is called "Setting the choke"


There is also another one on the other site

 

[Alvin in AZ]

I tried to loosen the distributor but it wouldn't budge.
I have to spray it with some release all.

BTDT and not had any luck with my '90 parts truck.
PB Blaster and months has had no effect on mine.

Try not to break it!

I haven't tried my-idea-myself-yet but so far three
guys have tried it and it worked out great for them.

-------------
Paraphrased from Lange's Handbook of Chemistry...
Thermal Expansion x10^6 of Alloys of:
Fe = 10 to 12 (stainless can be ~16)
Mg = 16
Cu = 16.5 to 19
Zn = 20 to 21
Al = 22 to 26
--------------

The guys packed their stuck distributors with dry ice
and they came right out. It hasn't failed us yet.

I need to follow my own advice and try it soon. LOL

Alvin in AZ

 

[BuzzGun79]

Also check those vacum hoses for cracks,along with the intake base. with the motor running carefully spray carb cleaner at the base of the intake where it bolts on the motor, if the motor idles down doing this,you have an intake gasket leak. vacum leaks = high idle

 

[FORDification]

Remove the gas pedal rod from the carb. Does it now fully close? If so, adjust the throttle rod as required.

 

[Alvin in AZ]

Remove the gas pedal rod from the carb.
Does it now fully close?
If so, adjust the throttle rod as required.

...and/or take the floor mat off the gas pedal?

Good idea Keith, that just might be the trouble.
Either way, he's the one that's gonna have to find it and tell us.

Alvin in AZ

 

[78F250SCCS]

The throttle stays in the same position when the rod is off as well. My first plan of attack is to get the distributor unstuck and time it if need be, then I'll focus on the choke. After that I will check my vacuum lines for cracks. And finally if I can't get this figured out I will convince the wife that it needs a carb and intake upgrade. Thanks for the tips guys and hopefully by saturday I'll get some time to get it straightened out.

 

[78F250SCCS]

So Alvin I was going to try the dry ice thing but I didn't have time to try and find some, so I was thinking of using one of my 20 oz air tanks from my paint ball marker. Think that will work. It comes out pretty cold.

 

[BuzzGun79]

if the dry ice trick dosent do it {i never heard of that one before} try heating the cast iron perimiter around the distributor carefully with a torch.keep the flame away from the fuel line.this will eventualy breakdown the tarnesh buildup that freezes them up.ive even had to use a slide hammer to remove them as for they can get stuck pretty good.

 

[Mil1ion]

Just buy a can of Corrblock from a marine dealer and it will dissolve the corrosion

 

[Alvin in AZ]

...going to try the dry ice thing but I didn't have time to try and find some...

Where you at? Fill out your stuff----------------------------------------------------------------------------------------^

Certain grocery stores carry it now days (I forget why).

I wonder about the cost of using one over the other or maybe... one and
then the other after the first one don't do the trick?

The problem with heating the cast iron is two reasons, the aluminum is a
better conductor of heat so will suck it up faster than the cast iron around
it and then the aluminum will get bigger faster with each degree increase.
(see table in post #8 Al is twice as "fast" as Fe

I need to quit preaching and start practicing what I'm preaching and get
some dry ice today and give it a try. LOL

Alvin in AZ

 

[78F250SCCS]

Alvin I tried to find where to fill in my info, not to sure how. Just so you know I'm in Thunder Bay Ontario, Canada. I didn't get a chance to work on my truck today. My dad and I got one of his broncos running and ready for a guy to pick up. Then we stripped down the front of my parts 78, pulled the 302 for a guy to come pick up. Then helped the guy who picked up the one bronco pull parts off two other broncos. My dad sold one beat up but running bronco, a track bar, front and rear diff, a windshield plus other little stuff for $450. I think the guy got a good deal. Then I had to clear a spot in a field to store my trailer for the winter. By the time all the work and bull-s*&ting was done there was no time for my truck.

 

[DNFXDLI]

User CP...then edit profile..then save changes

 

[BuzzGun79]

Yes Alvin i agree with you in theory.but when all else fails.i have successfully gotten them out with a little heat & a slide hammer,it wasnt easy.those distributors can really get froze in there.

 

[Mil1ion]

http://www.acf-50.co.uk/corrblock.htm