while i was heading out blacktail hunting, my 78 302 f-100 lost power (horse not electric). it has 1200 miles on a new block. first in the morning after it was warm, every time i was slowing down to a stop sign/light it would shut off. then when i got on freeway it ran fine, then after about 30 minutes it started to go miss a little and jerk, then it really started to sputter and could go up an incline, then i was able to go about 30 mph until i pulled over and shut the engine off. there wasn't any smoke just a strong gas smell. i tried to start it up again but it wouldn't turn over. so i called for help and waited about 15, then it started up again but ran very rough. i was able to drive it normally to our hunting spot at regular speeds but it was still rough. My question here is what could my problem be?
Why would it not be able to go over 30 mph and then drive normally? I was wondering if it could be the gas pump. it wasn't replace w/ the engine and is stock. it's the only reason i could think of. thanks for your help.

 

Sounds to me Like a DEFINATE Fuel supply problem.

Float has hole in it = Flooding
Choke is Stuck in the ON position

Dennis

78 F-150 429CJ C6 ,Silver w/Explorer Pkge
641/2 Mustang,Pre-World's Fair Car #8092
64 Fairlane S/C waiting for a 390-4spd.
68-Mustang.Sunlit Gold 80,000 miles

 

filter filter filter!
Same thing happened to me..I carry a spare one with me now!

 

Ole,
Filter comes to mind quickly. But! You smell gas. It's either a fuel leak or a fuel pump. The fuel pump can leak without you ever seeing it. If the diaprham leaks it will pump fuel into your block. Your crankcase ventilator will pickup the evaporating fumes and when the vehicle is shut off you can smell it for a short time. Smell the dipstick. If it stinks of fuel, you've got your answer. Change the filter anyways and keep an extra. You deer hunters have a bad tendency of bringing back mud and water in the fuel tank.
Good Luck, Have Fun,
KingFisher

 

I had a similar problem an d I agree with the other posts about checking the filter because it is the cheapest and easiest. But I also reccomend replacing your ignition coil. It should only cost about $15 and the problems you describe could be the coil overheating, the fuel smell could be associated with the engine flooding while it is off.

 

Definitely the fuel filter. I just restored a 77 F-150 with an inline six 300 ci that had sat for 4 years. Everything is running fairly well (thanks to lots of advice from this board) with the exception being that I have to keep several fuel filters in the tool box. The first time it happened the filter became plugged and split the fuel line by the carb from the pressure because the pump just keeps on pumping the fuel and it has to go somewhere, I'm sure the fact that the truck sat for 4 years and the fuel line was pretty dried out. I was replacing the filter about every 150 miles.

When it happens it is always the same, around the 2000 rpm the power just disappears.

I ended up putting a filter before and after the pump and just did away with the filter on the carb.

Don Sanchez
'77 F-150

 

As i've said before check your coil! its happened one too many times to me, if one of those wires are loose (is it just my truck or all fords?) and they tend to get loose easy, you will get some pretty nasty backfireing and a loss of power, i ended up just sodering mine to the posts. fuel filter sounds likely too. but you never know, just a suggestion.

 

Sounds to me like the carb needs some attention if you can smell fuel. How is the choke pull-off? Is it working?

-Brents