Just bought a 74 f100 with a 360 (2bl carb). All stock. Looks good and runs great when it is warmed up for a couple of minutes. It has been approx 40 degrees or so the past couple of days and if you try to start it after it has sat for a couple of hours the following happens. When i bought this the other day the guy must of had the truck warmed up already because i had no issues starting it (i must be a sucker).

It starts right up but is very sluggish and if you give it any gas it dies immediatly. i have to let it run sluggish (sometimes it stalls and you have to start it a couple of times) but it always starts right up. I have to let it run rough and sluggish like this for 3-4 minutes and then you can give it gas and it will run normal.

I did some research on this and i am thinking there may be a issue with the electric choke ( i am assuming this has a electric choke after reading multiple threads on this). Am i thinking correctly or ?

Thanks

 

You're on the right track. Refer to this post for everything you'd ever need to know about setting up the choke on a stock 2 barrel carb. The choke cap index paragraph is what you're looking for, but if that doesn't work, the post explains how to do everything from the beginning because there are actually a couple mechanisms that are responsible for how the carb works when the engine is warming up. Ignore the first couple paragraphs about the float, that was for a different problem.

https://www.ford-trucks.com/forums/7...ml#post6422219

 

On my truck right now the choke is taken off the carb and that is exactly how mine runs when it is cold. it will fire up run , maybe die on me. if not warm it will die when given gas. so my theory is that may be your choke is not working. good luck

 

x2 :)

360FE 2 barrel original 2100 here. :)
http://www.panix.com/~alvinj/file12/choke.jpg
Easy as anything here in AZ and I have a 4 speed manual which helps.

If I "crowd it" a little too much I have to quick and let back on it some to
richen it up because opening the throttle "too far" has just added air and
not much else. After it warms up, which takes like 10 minutes or more, it
runs like it means business. ;)

I richened up my low speed circuit back in '75 and since then have
experimented with that quite a bit and that prob'ly helps me out too.

How much tinkering with your old clunker do you want to do? ;)
I see mine as a "hobby". :)

I start my old clunker up and nurse it to 1500-2000 rpm and let it run until
I feel it smooth out. Kind of like when you break in a brand new engine...
I try not to let the sucker idle hot or cold weather when starting it cold.

YMMV

Alvin in AZ
ps- no choke problems that can't be fixed with a hacksaw and hoof rasp! ;)

 

started messing with it when i got home. Took off the air filter and just touched all the lines, vacuum lines etc. noticed alot. Did not even get to the carb. i added 2 pictures to my gallary (74 ford). There are several vacuum lines that are very loose (pull right off) and the vacuum tree on the passenger side of the carb has a empty spot (nothing hooked up to it). I looked in the forum and think this is the connection point for the automatic trans (i have a manual, so what do i do with this? nothing?). Also there is a big line coming from the round smog pump at the front passenger side of the truck that is just plugged off and not hooked to anything. I am not sure what is needed or not needed yet on this vacuum system. i ordered a manual today (cant wait for it to get here). thanks for the help

 

Any vacuum connection that is left open must be plugged. Put a vacuum cap on the unused port on the vacuum tree.

The big port on the smog pump goes to a check valve that runs to exhaust. It's not a big deal if it's open on the smog pump, but the exhaust-end should be plugged if it's not in use.

The arrow in your second picture is the vacuum advance on the distributor, typically it runs to ported vacuum from the carburetor.

 

I added a couple more photos to my 74 f100 gallery. i feel stupid but am trying to understand this darn thing (cant wait until my shop manual comes). Anyway, in one of the photos i am holding a vac line that according to above is supposed to go to a exhaust check valve (where the hell is the exhaust end?). i just came back in and searched the engine compartment outside with a flashlight (dark out) and can not find it. As stated above i just bought this truck and am going to replace all the vacuum lines as many were loose, cracked etc. Just want to make sure i get everything i need. Then i am going to rebuild the carb and attempt to tune (per the note above). i am hoping after this she will behave. I looked at this link https://www.ford-trucks.com/forums/8...mog-stuff.html and am trying to follow it. i do not see the bypass valve or where this exhaust port is on my truck. Sorry and thanks for the help. i also tried searching actual photos in the forum but did not have any luck.

 

I got home today and replaced all the vacuum lines except one. there are 2 lines coming from the passenger side manifold. One line goes inside and is hooked up to the choke (metal line wrapped in metal that goes to the choke). The other line is metal (stuffed in a hole in the manifold (not sealed up very good) and is then converted to a rubber line and goes to the carb. Is this ok?

2nd, then tried following the fmc400 carb procedure. i loosened up the 3 screws (i could turn it either way and the plate would move the corresponding direction) so i moved it all the way back and it closed the plate (per the instruction). quote "Then, find the choke pulloff vacuum motor on the rear passenger side of the carb. There is an arm coming out of it which actuates the choke linkage.
". on the rear passenger side of my carb...is this the linkage that is connected to the choke? Or i have what looks like a vacuum diaphragm coming out of the driver side of the carb (rear driver side). I think this is what i am supposed to push. IF you look at my gallery it has a little white tip on it.

Sorry, i just want to make sure i understand this fully. I dont want just to go thru the motions i want to really understand what i am doing.

Thanks,

Rich

PS i got a haynes manual today and am not finding it very useful for items like this. covers the basics.

 

This is how they should be hooked up, however there should not be any leaks.

You're correct. Your carburetor is a 2100 which has the pulloff mounted on the air horn, behind the choke tower.

 

I am really trying to understand this but am having a hard time. Sorry.... i am still in step one (choke pulloff clearance) of the carb adjustment procedure. I turned the choke all the way back and shut the throttle body, i then pushed the diaphragm all the way in and the throttle body opened up about 1/4". I hold this in (i think that this space is supposed to be 3/32" when this is pushed all the way in...correct?). i tried adjusting both set screws in this photo and neither one made a difference. i am obviously doing something wrong. am i correct in that i am to adjust the bottom screw in my photo? when i adjust this screw in it locks the linkage up (screw goes below it and does not allow it to move). Help please.

Thanks

 

OR POSSIBLY TELL ME FROM THIS PHOTO. I JUST FOUND THIS ON THE NET. ANY HELP APPRECIATED.

THANKS

RICH

 

Let me make some clarifications, I will use your first picture. The screw on the bottom - the one where you say "is this the adjustment for pulloff" - that screw is used to adjust fast idle speed, as in the RPM the engine runs while the choke is on. Here is some more info - on many 2100 carburetors, the piece that actually touches the fast idle cam is a small tab. However, some have a longer fast idle speed screw, and the tip of the screw is what actually rides the cam. The screw on the top where you've said "i believe goes on the second step of the cam", the one with the hex end - that adjusts the fast idle index. If your cam is out of index, you use this screw to adjust that. The screw that adjusts the pulloff clearance is a tiny set screw and it is underneath the pulloff on a 2100 carburetor. If you look underneath the air horn, directly under the pulloff that you are pushing down, you will see what I mean.

You're on the right track, I think you just had which screw is which incorrect, and that's probably my fault because I think the guy I originally wrote those instructions for had a 2150 carburetor and yours is a 2100 which operates by the same principles but the choke pulloff and often the fast idle linkage are slightly different.

 

pulloff clearance adjustment screw. i finally found it. the screw head was stipped, had to use needle nose vise grips to adjust. i had to adjust it almost 6 turns...wtf!!

http://i51.photobucket.com/albums/f3...fclearance.jpg

Just want to verify. i put a arrow to the big v - groove on the photo. it looks like there is also a smaller groove cut in this piece directly above it (hard to see in this photo). am i to adjust to this big groove? or possible the small groove above it?? not sure if this is a defect in the metal or what (small groove). sorry to keep bothering i just want to get it correct. if it is the big groove, this setpoint is out to lunch as well (just like the pulloff clearance). i am amazed how off this carb is.



almost there, thanks.

Rich

 

The "V" on the fast idle cam is right where your red arrow is pointing. When you have the choke in the pulloff position (choke spring trying to shut the plate all the way but the pulloff holding it open) and you bump the throttle open then back closed, you want the little tab right beside the fast idle cam to be resting directly on the V.

 

i have adjusted it to the v-groove on the can, my screw (i have a screw not a tab) is resting in this groove and basically is holding the cam up and not allowing it to fall any farther down (because the screw is in the actual v groove ). does this sound correct.

my 4 volume shop manual is supposed to come tomorrow.....