Hello guys, Within the last three weeks or so my truck has quit on me while driving down the road. The truck begins to stutter as if it is out of gas, chugs, and then stops leaving me to pull over and get a friend to tow me. The truck then will start later on in the day and sometimes as soon as half an hour after quitting. The truck is a 1976 f-100 with a 360 and fmx trans. I t acts as if it is a fuel probleam but with it starting later on throsa me for a loop. I now beleive it to be my fuel pump, but all other expereiences with fuel pumps have been with them stopping and never working again. Just in case you were wondering the fuel filter is brand new along with all the fuel lines. Has any one else had similar probleams, and also do you think that my probleam is with the fuel pump? I need to fix this probleam very soon.

 

Is the fuel lines close to the exhaust?? Sound's like a vapor lock problem to me.

 

When it dies, did you check to see if you were getting fire? Sometimes the coil will overheat and kill the engine.
You also stated that the fuel filter is new. Is it a see-through filter and in a location that you can see that it is getting fuel? There could be an inline filter at the carb. Did you replace it also.

The fuel pump could get weak and still deliver enough fuel to get it going for a little while, but not enough to keep it going. This is one sign of failure.

Did this start after you installed the new fuel lines? The fuel line is not too close to the exhaust manifold is it; causing the fuel to boil?

 

Next time it does this.
Without it running:
Open the hood & check the carb for fuel delivery by moving the accelerator rod to see if there is gasoline spraying into the carb.

If there is fuel spray,I suggest it is the ignition modulator that is the problem.
Pick up another one for when the engine dies again.

Things that could be possibly wrong:
1) Fuel delivery
2) Igintion Module
3) Ignition Switch
4) Wiring

 

My dad's used to do that alot and he said it was vapor locking then we installed a universal napa electric fuel pump right after the gas tank and it hasnt done it since.

 

Heat shouldn't kill a mechanical fuel pump. If there was gas in the oil or something...

I vote with Mil1ion, except that I'd add: touch the electronics box as soon as the vehicle dies. It should be really hot (for an electronics box). Heat does kill electronic components.

ash
['They die when they overheat, and they overheat when they die...']

 

Thanks guys for the quick response's. In terms of the fuel filter it is a inline one at the carb and has been replaced. My fuel lines are routed the same as stock however, I do have headers. I was hoping someone could explain the vapor lock thing to me.

Also I was wondering why if per say the probleam was the coil or the ignition module box why it would act as if it were running out of gas. Would the spark not just stop then instead of being spread out over a 5 to 8 second stutter/chug? I'm not to familar with this aspect of the vechcle and any explanation would be much appreciated.

As for my course of action i think i will gather up a box of extra parts of the aforementioned types to keep in the truck for the next time. As well as do all of the things everyone has mentioned so as to determine the true source of the probleam. I'm actually looking forward to my truck quitting so i can solve the reliability issues soon. Just hope its not raining.

Thanks guys

 

When my truck ign module died it just quit giving spark. It did not allow the truck to restart.
I would bet a soda that you've got a clogged fuel filter. I know that you changed it already. But you might have had gunk in the lines or rust from the tank make it's way to the filter.
When my fuel filter clogs it acts the same way. The engine sputters and dies but will restart. I use the quality screw in fuel filters made of paper filter elements. Everytime I replace the filter I use a tubing cutter to carefully open it up. It shows lots of rusty crud every time!(Ya, I know I need to replace my fuel lines. I will soon.)

If I were in yer shoes, I would check the cheapest/easiest things first. Assuming no vacuum lines are missing/rotted, I would replace that $2 filter and open up the old one with tubing cutters to verify that it is in fact clean. Then attack the other troubleshooting steps mentioned by the others.

 

Igintion module. As it gets hot it will start to fail. I went through this with my 302ci. I changed filter and pump and coil only to find out it was a $15.00 module.

 

My truck did the smae thing and I thought it was a fuel problem, but it turned out to be that the wiring that runs down inside the distributer was fried. When it got hot the truck would die, then I could restart it sometimes within half an hour. Check it out! The new wiring is pretty cheap from any parts store.

 

I had the same problem in the same truck and after spending 150 buck I found out all I needed was a new stator in the distributer.

 

i had a brainbox go out on my '77 and it did the same thing as above...i would check it out

 

I had the same symptoms when I bought my bronco. At the advice of others I had replace the ignition coil and experimented with fuel line location (vapor lock).

Problem turned out to be a rusty gas tank. The filter would slowly clog up with sediment and once it got clogged enough, the sputtering would start and then it would die. Let it sit for half and hour and I could drive it until it started sputtering 20 mins later.

Split your fuel filter open and look for rust. Mine was packed.

 

i have had this happen before what it was is i replaced the fuel lines with the wrong fuel line size make sure you use 3/8 tube i use5/16 by mistake this caused the fuel pump to suck th hose shut getting no gas to the carb i changed the line and it has worked ever since