Hey guys, I've almost got the truck running, I can run it but only with a spray bottle and gas. Lol It's an 85 f150 302 with a motorcraft 2150 2bbl carb. I think it's an adjustment issue? I started playing with the adjustments and got it to almost start, in fact it did run for about 30 seconds on its own before it stalled out. The carb is fresh off a rebuild... Where do I go from here? Anyone know how many turns the screws should be in or out to start out at? Thanks for all the help I've received from everyone here so far!

 

Make sure carb is being supplied with fuel, not too much, not too little. A mechanical fuel pump needs to supply roughly 1 pint (16 oz) of fuel in 30 seconds under all conditions. (It won't burn this much, hopefully) This is important.

If fuel deliver is too weak or, too high, it will never run right, may start on fire, etc. Everything downstream is predicated on proper fuel delivery to carb. If fuel pump is old, truck sat for 20 years, just replace it.

First though, blow out fuel line with compressed air backfed into fuel tank, maybe 10 or 20 PSI. Then get engine running with a tablespoon or so of fuel into carb and direct fuel line into a clean measured container.

If everything seems OK here are some tips on what to check and carb setup, then proceed with setting the float and idle mixture settings. Let us know how it works out.

http://www.junkyardgenius.com/holley/tune01.html

 

Leave the gas cap loose when you blow into the tank.
Otherwise the chance exists that you can blow the rollover valve out of the grommet on top of the tank.
Then you will have to either drop the tank or pull the bed off to replace it.

 

Rollover valve? Sounds pretty fancy!

 

Just an FYI: make sure the fuel supply lines, especially from pump to carb aren't kinked. I replaced mine and bent them myself, and still effed up several bends. It was frustrating to have to keep going back to NAPA to buy another fuel line, but I wanted to be sure I wasn't starving the fuel bowl.

Also, if you look in the fuel bowl and see two colors of gas, that probably means you've got too much crud in your gas tank and it needs replacing. Possibly lines too, although you can blow them out with some sort of cleaner.

Just trying to help. Mine was down for 10 months but it was mostly vac lines I didn't hook up correctly. But I certainly learned a lot of the stuff you are probably learning right now.

 

Tank vent check valve that self seals if inverted.
Come on man, lets not be stupid.
I say Kleenex, you ask about facial tissue.....

 

LOL!!!
______

 

Yeah I had the problem running the line from the carb to the pump of it kinking, I got tired of it so I bought some nice braided stainless steel fuel line for that section! But your comment makes me wonder if I replaced the rubber fuel line section with the correct size... It's only a small section thats rubber, maybe a foot that connects the steel line to the sending unit but I do recall struggling to get it over the steel line, I'll start there, try it, then do the tests that were suggested above!

 

Everything is pretty much new, I replaced about 90% of the components including the fuel pump so I know that is not the culprit, that being said, however, I'm wondering if I got the sizes of fuel line correct, I'm going to check on those, and proceed to do the test you mentioned! Thanks tedster!

 

The sections of rubber line were too small, replaced them, but didn't make any difference, I will test to see how much fuel is being delivered tomorrow and give you guys an update!

 

My truck is 3/8" supply and 5/16" return.

I don't know about your Autolite carb but most Holley/Motorcraft carb idle mixture screws are good to start at about 1 3/4 turns out.
Then adjust for highest vacuum, set the idle speed and adjust vacuum again until it's right.

 

Yeah mines 3/8" but mine doesn't have a return line

 

It's not getting any gas at all now.... Tested the fuel pressure, my fuel pressure is good, 6 lbs/sq. in... Its got about a 1/4 tank of gas maybe more... I'm at a loss for words!

 

Pressure is good, volume is not. Replaced all rubber lines, backflush with air pressure?

 

Yeah did all of that but I figured it out.... My sending unit doesn't come anywhere close to the bottom of the tank, think I got the wrong one but, I had made an extension for it useing a section of metal fuel line and a small piece of rubber hose, well I must have used the wrong rubber hose because I have some thats fuel grade and some that's not, because the rubber got eaten alive! This time I made sure to use fuel grade and it's working! Thanks all of you for your help! It was just my own stupidity all along.... Lol