F100 , hmm why would it do this ?

I took the F100 out today for spin, (Chevy 350 c.i. and 700r4 automatic) I was driving around town all day with no hick ups. I stopped for a bit left the truck idling to let some air out of the rear air shocks. Jump back in and drove off. It then start lurching for a few seconds when I accelerate. Then is was fine , then later started bucking and stopped and was intermitent. then lurching again. Stopped, got out maybe something with acc. pedal. nope. Put in park and the engine seems to rev fine when I hit the acc. rod under the hood. It was in the low 80's today, would the carb maybe be boiling do to heat ? I parked it , a little puzzled ( tank is half full, carb acc, pump ethinol fuel ? I haven't changed the fuel filter , maybe getting plugged, and **** is getting through. Hmm , scratching my head.

 

I'd check the cheap stuff first, yes ethanol is bad on carbs, fuel filter should be changes tank drained and cleaned just good maintanance. Sound like trash it the carb to me 80 is not hot and you didn't say the engine temp was high, so my guess is the fuel system and or the ethonal fuel itself.

 

Tank clean?

 

check fluel lines as well! found out mine were clogged on the 69 by accident after months of trying to get it to run right.

 

Had to change my fuel pump the other day. It started just like yours, it runs fine in park but in gear it starts burnin to much fuel for the pump to keep up. It did this randomly and started to increase after a week. Just a thought. Good Luck.LB

 

sounds like she ****ed up some **** in the mid or high speed jet..or dirty carb all around..

would suggest taking it off and cleaning it up all the p***ages, and new fuel filter

 

engine was running just a hair under 180 degrees. The truck is running a 10 gallon aluminum fuel tank(looks darn clean). I have new hose and filter and clamps, maybe time to change them. I heard the ethonal is really bad on hoses, and acc pumps on carbs( the ethonal breaks down the rubber)

 

tank is clean, the fuel filter is very questionable. The more I look at it, I may change the hose and filter. Fuel pump ???

 

is there a rubber line between the pickup/sender and the hard line? might be leaking air there. i bought a running Mercury wagon with a 460 because the owner thought it had a bad tank.

is there a liner/lining in the tank that could be peeling and clogging the filter?

 

Good idea,It cant hurt,the standard fuel pumps are pretty cheap too while your at it,if only for preventative maintenance

 

Had this problem on my truck. The fuel pump gets clogged with lots of fine paticles or debri. After that the inlet now has a hard time getting enough fuel through it. It ended up prematurely wearing out the pump. It would push just enough fuel when idling to look like it was getting the right amount of fuel but under acceleration the pump was not able to keep up. This caused the symptoms you posted about.LB

 

Maybe it's just pissed that someone put a Chevy in it.




Or some of what the other guys have said

 

What are you running for total timing? I had a similar issue when i got mine together, same setup as yours. Ran like a champ for about 6 miles, pulled really strong until CLICK, and bucking. Turned out I never set the total timing. It took me a year to figure it out, though. I kept thinking something was broken because it ran so well at first. If not that, then change the fuel filter. I have one coming out of my tank, and another between the pump and carb.

 

K.i.s.s. rule applies here! Change fuel filter and tighten lines well. A friend of mine just about lost a car today because he got in a hurry and forgot to tighten a fuel line. A good samaritan with a fire extinguisher saved him from losing the whole car.

 

Are you running an electric fuel pump? Could be overheating? Not enough return to cool the pump.

 

Thats what I was thinkin...

 

In 1979 I was driving down the highway in my '53 F-100 (327 Chevy, Turbo 400) and it started the same kind of intermittent bucking. Turned out that the fuel line was rubbing on the floor of the cab and had a hairline crack in it on the top side. The body mounts had settled over time, enabling the floor to come into contact with the line. Took me forever to find out what the problem was.

Oh, and my F-100 liked that 327 SBC just fine!

 

I will start with a new filter and hoses, maybe add a filter also after the tanks, and run one between the carb and fuel pump. Let me know if this will be ok. I don't want the mechanical pump to work to hard..

 

no electric pump, I thought maybe heat boiling the carb..

 

I'd check the filter first. The last time this happened to me, on a TBI truck, I thought the filter had gone bad so I changed it 80 miles from home in the parking lot of the parts store, to find a small leaf on the tank side of it. How the hell it got in there - and apparently through the in-tank pump and sock - is beyond me.

 

It's not pissed ! It's built Ford tough with Chevy stuff. Besides a bone stock mechanical pump, does anyone make a high performance mechanical pump ? Or is just basic stock ok.

 

never had a ford motor do that........ someone is trying to tell you something

 

Had similar issues, turned out to be the little spring clip that holds the needle to the float arm had fallen off causing the needle to bounce around in the seat.

 

I will keep that in mind.

 

A basic stock pump was ok from the factory and the one I bought a few months ago was only around 20 bucks,so as I said before,putting a new one on is inexpensive and should eliminate any fuel pump doubts.

A screen on the pickup in the tank is a good idea but I dont like the idea of a filter between the tank and pump.
Between the pump and carb is best.

And yes believe it or not I also had a 53 ford pickup with a 350 chevy years ago when I was around 15 or 16 (my cousin would drive it in town for us until I got old enough to get my license)and it would only quit running when we got into town cruising mainstreet It was a sharp truck but it was still embar***ing when it would quit and we would hafta jump out and push it to the side of the street.........always had plenty of voluntary help tho

And yes,like arkiehotrods said,the best I can remember I beleive it was a faulty line ****ing air between the tank and pump.

 

Bought a new pump today and filter, new hoses. I did find out that they make a new fuel hose that is ethinol resistant. I explained the ethinol in the gas ( 10% but more like 15 % around here) said they had a new hoses that resist rot for ethinol blended fuel. Didn't get around to installing the pump this evening, but will get after tomarrow afternoon. I hope this helps, the stock Carter pump was cheap, and I get jobber discount to boot. I got a better look today at the filter to the carb ( ugh) and the filter they put before the pump , doesn't look any better. I had always thought a filter before the pump was a good idea. Helps keep the pump clean. So a inline filter before the pump is not a good idea. Just curious why ?

 

I've always bought regular OEM fuel pumps, never had a problem with one and the price is right.

Bob

 

I had a filter before the pump on a few cars. I have a few old Holley canister filters (takes the old Ford fuel pump element) that gets moved from ride to ride. I like it because it gets away from the engine heat and I could just slip under the frame rail and change the filter.

Bob

 

Well tackled the filters and fuel pump this afternoon.. Went for a small test drive, checked for leaks (all ok) Seemed to run better. I did take a picture of the Purilator inline(3/8") fuel filter, ( chrome metal and gl*** with plastic/metal mesh screen inside) Wow it was really bad, the picture I took is didn't show the break down of filter screen. Next will getting underneath and replacing the hose from the tank.