Good morning to all persons on this site, I am currently having an issue with my 1980 Ford F100 Ranger with a 302, a 2 bbl Motorcraft carb, and a C6 transmission. I have recently rebuilt the carb because I wasn't getting any vacuum through the carb. Well no success. I brought her home from work today and now it is starting to stutter at 40-50 MPH. Is there a way to regain the vacuum in the carb or is it trash now. Also, how do you adjust the fuel-air mixture screws on this thing? Please help need truck to get back and forth to work. Thanks to any one willing to help.

 

Are you trying to say one or more of the vacuum hoses connected to the carb don't have vacuum? Or what?

The carb necessarily has to have vacuum, the engine wouldn't be running at all without it.

 

Right now the only vacuum I have going to the carb is from the egr and the intake manifold, however, all the vacuum ports on the carb are not pulling a vacuum.

 

When I have a myserious problem like that, I just go back to the basics of a tune up.

1. Make sure the ignition timing is set correctly. I set mine at 12 degrees advanced without the vacuum hooked up.

2. Make sure the ignition components are in good condition. The reason I start with ignition is because a faulty ignition can mimic a carb problem.

3. Some ports on the carb are ported vacuum, meaning that there is only vacuum there if the throttle blades are open. You can test this by using your finger or a vacuum gauge-- just hold your finger over the port, then blip the throttle open. You should feel or see vacuum present until the blades close.

4. I have a flexible screwdriver (aka carb adjusting tool) that has different tips to fit different adjustment screws. The tool kind of looks like a mini roto rooter. The idle mix adjusting screws are still difficult to reach. I had to have one hand near the tip to hold it steady because mine were a regular flat blade

5. Make sure that all the vacuum hoses are in good condition. Dry rot or brittle hoses can have a leak in them. If in doubt of the condition, just replace them. New hose doesn't cost all that much.

 

Ok, I recently did a tune up on it. I would really like to find out how to adjust this thing. I think it just may be out of adjustment.

 

Choke adjustment. Must be done on a cold engine.

1) Verify that the spring is engaged properly to the lever. While it is apart, check the gasket alignment so that heated air can flow through the choke. I had to trim mine a little bit to make this happen.

2) Space open the throttle blades a little bit so the choke mechanisms can move freely.

3) Apply vacuum to the vacuum break. Choke plate should open about 1/4 to 3/8" @ top.

4) Loosen the 3 screws that hold the choke spring. Turn clockwise until the choke plate moves more open, then back until original spacing provided by vacuum break.

5) Tighten the screws.

6) Release vacuum. The choke plate should close all the way.

Idle mix adjustment

1) Get a screwdriver small enough (short) to fit or use a carb adjusting tool with a flat blade tip. Either way, your hand will be near the base of the carb.

2) Initial setting is typically 1 1/2 turns out from LIGHTLY seated.

3) Start engine and run until warmed up.

4) Turn in/out in 1/4 turn increments. If engine speeds up or smooths out on the first side, then turn the other side the same direction the same amount.

5) Adjust idle speed if necessary.

6) Repeat steps 4 and 5 until satisfied with idle quality.

7) A vacuum gauge can help dial in the idle mix better after you can't hear a change with your ears. Just adjust in smaller increments until the highest vacuum reading is attained.

If your problem is still there, it may be related to emissions equipment if it is still functional

 

There is plenty of vacuum on the intake manifold vacuum line tree if you need it. If you have a port with no vacuum on the carb, like someone else said it probably is not supposed to have vacuum unless you open the throttle.

All ports are easily cleaned when a rebuild is done, using air, the nozzle on a aerosol can, etc.

 

Thanks everybody, I will keep looking and figuring out the problem. I will also attempt to adjust the carb to get the idle right.

 

This might help you:


Motorcraft 2150 2V Theory and operation
Motorcraft 2150 2V external systems
Motorcraft 2150 2V internal systems
Motorcraft 2150 2V power valve chart
http://www.therangerstation.com/tech..._2150_carb.pdf
https://www.ford-trucks.com/forums/8...-answered.html

 

Thanks ctubutis.

 

NP.

BTW those are links from the new sticky section (which I keep hoping to finish "real soon now").

-chris

 

A quick question, If the ball and tube where the venturi attaches were not replaced, would that cause the carb to have problems?

 

Yes, those are the check valve parts for the accel pump. That would cause the accel pump not to pump fuel, and you would have a terrible bog when you hit the gas pedal.

 

Great, I think thats what is causing all the problems because I dont think I have ever replaced them.

 

I thought you meant you had left them out. Usually they are lost because you don't know they are in there, and when you turn the carb over the ball falls out and you don't realize it. They really don't fail and need replaced, but the kit usually does have a replacement ball in it. I have had them get gummed up with old gas and get stuck though, but a good cleaning with solvent will fix that.