mmc16226

84 f150 with a 351 windsor stalls out / won't start when at full temp. rebuilt carb (4bbl), screwed it up, stem poured fuel out the top. Bought a rebuilt one, worked great...until it got to full temp. Then it stalled out first time I hit the gas. Now I begin the 1.5 hr. wait so I can get it started again. Anyone have an idea what it could be? Already wasted $400 on rebuilding carb and then getting a new one. I don't want to have it towed.

transmaster

Sounds to me like you have a classic case of a vapor lock. You didn't mention what the ambiant tempurature is where you live. Remember so much of our fuel is polluted with corn squeeze and this stuff has a lower boiling point then gasoline. Another thing it could be if a coke that is out of adjustment. When it stalls is there a strong smell of gasoline, if so that is a choke problem, either the electric coke setting or the choke unloader out of wack. I there is no strong smell of gas then it is indeed a vapor lock. There are a number of things you can do to help prevent a vapor lock. first thing you want to do is check the routing of the fuel lines make sure they are not running close to anything that gets real hot like exhaust manifolds. A plastic spacer on the carburator can help, this puts the carb up above the intake manifold and help keeps the carburator cool. Do you have a mechanical, or electric pump either way if the fuel pressure is low that to will contribute to a vapor lock.

mmc16226

I live in GA, it has been doing this since Feb, so we've gone from 40s to 90s in temp since then. new carb has a new choke. that was my first thought too, but choke is completely off after about 60 seconds. there is a sheet metal shield (I presume to block engine heat) under carb, as well as a 1/2 inch thick spacer gasket. fuel line snakes all around the front of the engine block, which is covered in sludge as seals are all leaky (has 180k on it. Yes, I smell gas, but I always have since I bought it 3 years ago. However, when I bought it, it had a 165 degree thermostat in it, and wouldn't pass emissions, as it ran really rich. I put the stock thermo in it, and it passed emissions fine, no problems for 2 years, but now this. I bet if I went down to that thermostat, I wouldn't reach the temp that's giving me trouble, but I have to pass emissions one more year (no emissions testing after 25 years). Any other suggestions? Thank you SO much for the advice.

mmc16226

going to replace fuel pump. $20 is worth a shot at avoiding the mechanic. Anyone have a good idea at the best way of getting to the old one? Looks like an absolute bitch. Tucked behind a bracket holding up the power steering pump, and removing that involves removing the compressor bracket, etc... What have I gotten myself into????

Good old Bill

Jack up the truck, get a 9/16 flex socket and go for it from underneath the truck. Using that socket and an extension or two should give you access. I prefer using 1/4 drive anytime I work in close quarters. Shouldn't have to mess with power steering or A/C. Good luck.

transmaster

That was one of the best investments I have ever made was in a full 1/4 in drive and socket set. I use it more then my 3/8 and 1/2 inch sets. One of the most useful things I have purchased it a set of whobble drive extensions.

mmc16226

still have the problem. Maybe the fuel gets too hot in the line, I don't know... Thanks for the help guys.

Good old Bill

Are you sure you have spark? TFI modules have been know to act up with temperature. Also check for codes.