*EDIT* Signature where I added truck details isn't showing up do here they are: 86 F150 4X4 / 300 i6 / C6

I finally got my truck back from the mechanic that sold it to me on behalf of his aunt (never met her). It sat for up for a while so he did some work to get it back running. Here's the work he did:

New fuel tank
new sending unit
changed all belts and hoses
new thermostat
trans fluid and filter
oil and filter
new water pump
new battery
rebuilt starter
new solenoid

He also "rebuilt" the carb. He said he soaked it in cleaner for 5 days and then put it back together. I picked the truck up a couple days ago and it ran, but not smoothly. On the way home the front driver side caliper locked up so I replaced both front calipers and pads and everything was good for 2 days. This afternoon I parked it on the street and 6 hours later went to put it in the driveway and it turns over but won't start. Wasn't sure if it was spark or fuel so I had my daughter crank it while I sprayed carb cleaner in the carb and it started. It was rough as hell but it kept running while I was spraying. Here's the carb (not sure what model it is)

<a href="http://s28.photobucket.com/user/dash13/media/86%20f150/24B3DEE1-447E-41B0-899F-5957E9662CF6_zps9yz2ilxp.jpg.html" target="_blank"><img src="http://i28.photobucket.com/albums/c236/dash13/86%20f150/24B3DEE1-447E-41B0-899F-5957E9662CF6_zps9yz2ilxp.jpg" border="0" alt=" photo 24B3DEE1-447E-41B0-899F-5957E9662CF6_zps9yz2ilxp.jpg"/></a>

I was trying to figure out if maybe the fuel guage was wrong and it was out of gas so I held the butterfly open and had my daughter pump the gas and saw it squirt out this jet:

<a href="http://s28.photobucket.com/user/dash13/media/86%20f150/F6145462-6767-4667-83B9-474158548C1C_zpsjgrjyado.jpg.html" target="_blank"><img src="http://i28.photobucket.com/albums/c236/dash13/86%20f150/F6145462-6767-4667-83B9-474158548C1C_zpsjgrjyado.jpg" border="0" alt=" photo F6145462-6767-4667-83B9-474158548C1C_zpsjgrjyado.jpg"/></a>

Any suggestions?

 

Pump it 3 or 4 times before cranking it and then crank it over. Each time you pump the gas up and down that little nozzle will squirt some fuel in there. So load it up by pumping it several times, and then try it. If it starts and then quits, pump it several times again and then get ready. Crank it, and when it starts, and then tries to quit rapidly pump the pedal to try and keep it from stopping. It may clear up a little bit and then try to quit again, so start patting the gas again, and try to keep it revved up. Eventually it will start trying to run by itself.

If the above scenario works, your choke it probably not working or not adjusted correctly. The choke is that rusty flapper door on top of the carb in the picture below. In the picture it's partially open, but if the engine is cold it should be shut AFTER YOU HIT THE GAS PEDAL TO THE FLOOR ONCE. If it won't close you need to adjust it.

See that big silver thing in the background of the picture attached to the carb? It should be black plastic on the other side. That is how you adjust the choke, loosen the 3 screws and turn it WHILE YOU ARE HOLDING THE CARB WIDE OPEN so the rusty choke door closes.

 

OK, the choke is working but it doesn't seem like it's getting any fuel. Just a tiny bit of fuel is dribbling out from the accelerator pump nozzle. Can anybody tell me where the fuel line comes in so I can test to see if the pump is working? I'm guessing I can unhook it then crank the motor and make sure it squirts fuel, right?

 

Ok, dumb question time... What's this?



I unhooked the hose going to it on the guess it came from the fuel tank and had my daughter crank the truck. No fuel came out. Any help?

 

That's your fuel pump. The rubber line is the suction line, the metal line in the back is the pressure line. Even though the rubber line is the suction line, you still should have had some fuel spillage when you took it off.

In the picture below, the metal line from the pump snakes up the front of the engine and ends up at that round silver thing in the lower part of the picture. That round silver thing is the fuel filter.

 

If you want to experiment, you could get a long hose, take the other hose off the fuel pump and slip the long hose on instead. Get a small lawnmower gas can and stick the long new hose into the can. Then keep cranking, it should pull the fuel out of the lawnmower can into the pump and send it up to the carb and it will run off the lawnmower can of fuel.

 

Welcome to the forum, Dr. Johnny Fever!

First things first... you stated that the tank and sending unit have been replaced. Are you certain there is enough gasoline in the tank? Check the fuel lines all the way from the fuel pump [that looks like the original rubber hose with factory clamps] to the tank. The hoses must have been disconnected to replace the sending unit and may not have been properly reconnected. Sometimes, when replacing tanks, people remove the factory sock [filter] and the plastic piece which it connects to can break off. If this happens and a short piece of fuel line is not connected to the bottom of the pick-up tube, the pick-up tube will be shorter and cannot get fuel when the tank is low. You might run out of gas even with the gauge @ approximately 1/4 tank.

Also, the rubber fuel line hoses get old and dry out. This can cause cracks or holes and when the fuel pump tries to suck the fuel, air gets into the line. Look for any rubber fuel line sections.

Since the carburetor was removed, check the two bolts which hold it down to make certain they are snug [not too tight!]. If the gaskets between the carburetor, the EGR adapter and intake manifold were possibly reused, there might be a vacuum leak.

Look at all vacuum lines, hoses and manifold trees for the possibility that one is missing or loose. Any vacuum leak will cause the engine to perform badly.

Your truck is equipped with the feedback carburetor [1984-1986]. Look for loose electrical wires [O2 sensor, temperature sensor on top of the thermostat, wires to the side of carburetor on the driver's side, etc.].

Good luck!

 

Thanks for the responses guys. At this point I'm positive it isn't getting fuel, but not sure if it's a pump issue or a tank issue... heck, I'm not 100% sure it isn't out of gas. The gauge is showing 1/2 tank but I figured the new sending unit might be wrong for some reason so I dumped about 2 gal from my lawnmower can in just to double check. Still didn't start so I figured it wasn't that. Now I'm wondering if maybe it wasn't flat out of gas and 2 gallons wasn't enough sitting on the street leaning a little towards the curb. I have a couple antique Harleys but I work on all the time so I have extra fuel/oil lines laying around. I think I'm going to try running the fuel pump suction line into a fresh can of gas like Franklin2 suggested and see what happens.

After that I'll check the hoses as 1986F150six suggested. In order to check the sending unit I'm guessing I have to drop the tank, right?

 

If you are working on the side tank, you can squeeze your head up between the driveshaft and the gas tank and do some work up there. Since you just put it in, hopefully the locking ring will come loose easily and you can get the sending unit out.

 

I had a very similar problem, there is a section of rubber hose that leads out of the top of the tank (yes, you will have to drop it, but it's really not too difficult). Mine had a pinhole leak in that length of hose and I had the same symptoms as you; my carb jet would squirt gas but no steady stream, my truck would fire right up with ether sprayed into the carb but it would not stay running. Ditto to what was said above by the other guys: Check the rubber line sections, especially that one above the tank. That may be your issue, and if it is, it's fortunately a quite simple and cheap fix.

 

Ok, new info guys. I'm going to check the hoses to be thorough, but it's running now and I still don't know what the issue is. Here's the latest:

I had 2 2gal gas cans. I decided I was going to pour one into the tank and put the other under the truck and run the sucction hose from the fuel pump straight into it. After I poured the first can into the tank I cranked it just for giggles. Go figure, it starts. So then I was thinking the sending unit wasn't accurate even though it's brand-new. It was showing half a tank but I thought it must actually be empty. Yesterday I poured in give or take 2 gallons. Today the can I put in wasn't full, so figure on a gallon and a half. I drove it up to the gas station and filled it up. The dang thing took less than 8 gal - and that was packing it. So obviously it wasn't empty. I put in someplace between 11 and 12 gallons and what is the stock tank, 17? 19? Either way, there was a lot of gas in the tank. The guy I bought it from said he thinks it's a bad fuel pump and he'll swap it out for me for free. It sounds like a good deal, but my confidence is not high that this is actually a fuel pump. What do you guys think?

[EDIT] This is looking like a possibility...

 

Hopefully it's the fuel pump. Now that you have a full tank, if you need to do anything with the tank it will be very difficult. 19 gallons of gas weighs a ton, you can't drop the tank until you get most of it out. And you will be running around trying to figure out what to do with all that gas. Best place is to put it in another vehicle probably.