Car runs ok for 20 miles then dies occasionally on straights

[Anonymous]

Any ideas? 1966 Falcon with a I6 200 with load-o-matic dizzy and the stock carb, an autolite 1100 as I remember? I am thinking it is a fuel problem due to the fact that the car won't start without carb cleaner/starter fluid. I just replaced the fuel filter and the old one was old but clean. Carb? Fuel pump? Any ideas?

-Dan in Jensen Beach, FL

 

[Junk-Falcon]

ppp

 

[Anonymous]

1) If you let it sit for awhile, can you restart it?
2) If you remove the air cleaner, can you see any gas squirt into the carburetor barrels when you pump the throttle?
3) Have you cleaned the carburetor recently?
4) Have you checked your fuel line pressure lately?
5) Does it idle well?
6) If you loosen your fuel line at the carburetor, does any gas squirt out of the fitting?

 

[Anonymous]

When I replaced the fuel filter I thought it odd that I didn't spill _any_ fuel, the line was completely dry. The car had probably been sitting maybe a month at the most at that point. Dunno what that means.

I'll check for fuel squirting tonight.

The car does usually restart when it dies. Fairly often it will catch a little bit after it died and backfire. Sounds like a .22 but much louder. Sometimes the Falcon dies and I coast to the side of the road and it restarts fairly quickly. Usually once it starts dieing each death on that trip gets progressively worse. Like I will feel it miss, then later it will die and re-catch before the car stops, then it will die and leave me on the side of the road for a minute, then it dies and I'm on the side of the road for a good 5 minutes.

I haven't ever checked fuel line pressure, not sure how to do that.

The carb was disassembled and rebuilt 4 years ago. Lately I have sprayed it with carb cleaner but I haven't taken it apart and rebuilt it. I'm trying to hold out and get a new carb and dizzy so I'm reluctant to put money in this carb if I can avoid it.

-Dan

 

[JackFish]

It's popping and missing. How fresh is the gas, might be some water in there?

 

[mustang6]

If the fuel line going from the tank to the pump is dry when you take the line off the pump after you've been trying to start it, your fuel line/pickup in the tank may be plugged or maybe you've just lost the "prime". I find with some cars that sit for a long time that the line goes dry and they have a hard time pulling enough suction at cranking speed to prime a dry line. This is where some starting fluid or a little fuel down the carb throat usually helps- getting the engine to start and run for 15-20 seconds creates much more of a suction by the fuel pump. For cars that act this way, usually 2 or three runs with a fuel assist gets the line primed and the fuel flowing. I just followed this procedure last weekend for a car that behaves this way.

 

[XFlow_Fairlane]

I would check out the pump too. sounds like it is not deliverying enough volume

 

[63Futura]

My guess is that it is something to do with the fuel tank itself. Either the fuel pick-up is getting clogged with the junk at the bottom of the tank, and it is taking some time while driving to clog up the screen; or the vent for the tank is plugged, and after driving for a while, a vacuum is being created in the tank from the fuel pump pulling gas out of the tank, and after a while is unable to pull any more gas because of the vacuum being created. For the second option, I would suggest either a vented gas cap, or checking to see if there is a tank vent line, and seeing if it is plugged. My first guess would be the pickup being clogged with junk that takes a little while to cover the screen. I had that problem with mine.

 

[JackFish]

I'd agree with the crap in the system theories also. :|