this is my 1st post, hope everyone is doing good and would like to say hello! question is.....
i have an 86 f-250 w/351W, 2BBL and it is very hard to start on cold mornings and even after sitting for long periods of time like 5 hours or more. seems like it may be a choke adjustment problem but i'm not quite sure how to do that. i have a friend, who is a really good backyard mech, who says "rebuild the carb", but for some reason i think he could be wrong on this one. i've had a couple others tell me to check the choke adjustment but when i ask how to do that i can't get a straight answer from noone, usually, "i haven't messed with that in a long time" is the answer i get.
not sure if this bit of info would help but sometimes my in-line fuel filter will be completely filled up with gas but most of the time it looks as if its barely sucking the gas through, when the truck is warmed up, and the truck is at a nice steady idle. any advice would be appreciated. thanx!

 

personally, and i know many will disagree with me, i'm a fan of switching automatic chokes on the old trucks to manual chokes. i think it has something to do with the fact that i much prefer simplicity, and have an increased level of control. its a cheap switch, you can get the kit at most autoparts stores.
another thing you may consider, if its starting hard on cold mornings, is switching for to a lighter oil during the winter. this will improve cold starts. if you drive a lot of long distances, this isn't as good, but if its a lot of short trips, it won't cause any problems.

 

i was told by my mech friend not to go with a manual choke....he didn't give any real reason as to why other than it would only be a temporary fix to what could be a bigger problem. he says "i told you to re-build the carb" but my income isn't nothing to brag about.....he's one of them stubborn, grumpy mechs that you see in the backyard that try to make you feel stupid. i hope noone else takes that comment personal, i think you may know what i mean.
i did by the cable kit for a manual, just haven't installed it yet. i also must tell you that when i say its hard to start, i mean the motor really lugs when 1st started for about 15-20 minutes. i took a foot long stick and placed it on the accelerator pedal to keep it idling at a comfortable speed so it would warm up. once it warmed up, its good to go.
i checked the alternator...its holding a charge.
it has a new distributor and timing gears and the timing was set by a certified mech...
maybe i'm just imagining a problem that may not be there. i know for sure the rings are going bad because it does burn oil and also blows oil up through the oil filler cap...not bad, just a little. i hope that that is not the problem.
i know i have to pump the gas about 15 times before it finally starts and then it lugs real bad when its cold or when it sits for a long time and if someone could tell me how to adjust the choke i would do it. thanx for all responses. greatly appreciated. i love this old truck and would hate to have to send it to its last ride.

 

also, the truck has new plugs and wires, new electronic ignition module and the ignition switch rod was re-adjusted for easier starting. i did alot trying to figure this out but the only thing that i haven't done was adjust the choke. i don't know how and i would rather not pay someone to do it if i can help it...like i said, i'm stretched on cash as it is.
could the starter be going bad? i've had this problem with my truck for the 2 years now when i bought it. the starter probably would've burned up by now, wouldn't you think, if it was bad.
i know some vehicle maintenance and even some troubleshooting but i think i would classify myself as a parts changer more than anything.

 

i'm trying to remember everything...i run pennzoil 10W-30 in it all the time.

 

Pull the aircleaner off. With the engine cold, push back the throttle all the way once. There is a flapper door on top of the carb. That is the choke, and it should shut all the way after you hit the gas pedal once.

If it's not shutting, you can go to the passenger side of the carb, and there should be a round black thing on the side. If it has screws, you can loosen them and turn the black part till the choke flapper closes, and then try it.

If it has rivets, then you will have to drill them out and replace them with screws.

 

JUST WANTED TO SAY HI TO MY BROTHER, STEW, who will be probably reading this anytime soon. I TOLD YOU THIS WAS AN AWESOME WEB-SITE, BRO'.......
I'm sure he'll be joining soon once he gets an e-mail. He's a Ford man all the way.

 

Is it the same process for the 351W H.O. with the 4BBL? I'm having the exact same problem with my autochoke. When I first crank it, it'll idle up just fine, but so much as brush the accellerator and it's game over. Once warm, it runs like a champ.

Also, even when warm, if I open the carb completely (i.e. floor the pedal) there's a slight hesitation before it revs up. Sometimes even a slight backfire through the carb. The timing is correct, so I'm curious what might be causing this and how to fix it. Thanks in advance.

 

Yes, if you have the round black part on the passenger side of the carb, it works the same, and you can adjust it.

How old is this carb and has it ever been rebuilt? The hesitation sounds like the accelerator pump has gotten old and hard, and is not pumping fuel like it should. It may be time to put a kit in it.

 

Carb is a couple of years old. I bought the truck about 3 months ago and when I got it, it was idling rough. Had a serious vaccum leak that has since been repaired. I'm pretty sure the previous owner never did anything to fix it and just put up with the rough idle. Would this cause unusual wear on the carb or accelerator pump? The carb seems to be in really good shape visually, but I know that is only cosmetic. I can't see any carbon build up, but wouldn't be surprised if the rough idle/run (probably resulting a few too many backfires through the carb), hasn't caused some internal problems.

 

Well, the first thing to do is pull the sparkplugs and look at them. If the edges of the center electrode are rounded and not sharp, I would replace the plugs. I would also inspect the rotor and dist cap, and physically tug and wiggle around all vacuum lines you can find for brittleness and cracks. If you already have had problems with one line, others are sure to follow.

If everything seems ok, then I would take the aircleaner off, hold the choke open so you can see down in the carb, and then move the throttle ever so slightly. See if any fuel dribbles out of the squirter in the center of the carb. If it doesn't, let the throttle go and then push it back some more. If you really push it hard, you should see two strong streams of gas pour into the carb. But if there is any delay or they are weak, then your pump is getting old.

If you suddenly hit the gas pedal while driving, the engine takes a big gulp of air, and the pump squirts enough fuel in to match. If it doesn't squirt enough fuel, then the engine leans out and hesitates.

P.S. You can experiment some with moving the throttle, but don't pump too much fuel into the engine while doing the above experiments, because it will flood the engine.

 

For original poster "toms86ford". The pics are off of my '84, 351w, 2bbl, motorcraft 2150/feedback carb. If yours is similar and your choke linkage is free to move and not sticking, as Franklin2 said, w/ cold engine press throttle all the way once and choke plate should close completely and fast idle screw rests against the high step of the cam. Then after engine starts, vacuum is applied to choke pull-off which slightly opens the choke plate ~1/8th inch. If choke pull-off is bad or vacuum hose is disconnected, the choke plate will stay completely closed and no air will enter so it won't run or barely run. I think this may be your problem. Here's the pics...
1. https://www.ford-trucks.com/user_gal...148984&width=0
2. https://www.ford-trucks.com/user_gal...148985&width=0
Choke idle speed adjustment is the "fast idle" part in the 2nd pic. Check up to this point and let us know. Hope this helps.

 

thank you everyone...all my resources was eventually exhausted and in the end i had to just have my carb rebuilt. it was apparently "worn-out". the fella i had do it was reasonable on price and according to some of my friendly resources is one of the best in the ohio valley as far as a total rebuild. i'm not sure what it would take to rebuild a carb but from what i understand its pretty tough unless you know what your doing.
i think i'm going to buy one cheap from a junk yard and take it apart just to see what its all about.
again, thanx to everyone for all your help.

 

Plugs are pretty good, though I think I'll replace them anyway. Distributor, cap, and wires all look good and are fairly new. Vaccum lines are all good. The previous vaccum problem wasn't a brittle line, it was a missing line altogether. Still checked them all and they all look good.

Well, after doing all of the above, I climbed on up and checked the carb. It appears as if the accelerator pump is the problem. When I pushed the throttle all the way back, there's a slight hesitation followed by a fairly weak stream of fuel. I guess it's time to put a kit into it.

I'm wondering if it might also be the fuel pump. The originial went out and rather than replace it, the previous owner put an aftermarket fuel pump on it (not a high end one either) and rerouted the fuel lines from the manufacturer pump. The pump looks a little wimpy for the size of the motor (though I know looks are often deceiving). Anyway, I'm always a fan of keeping a vehicle as original as possible, so I think I'll replace the original and put everything back the way it's supposed to be.

Thanks Franklin for all your help. You put me right on the problem