I have a 52 F! with the V8 flathead. it starts fine and idles, but when I drive in warm wearther (>70 degrees) it starts sputtering when I approach 40 miles per hours. The hotter it is, the sooner it starts to sputter.

I have changed out the fuel pump, fuel filter, thermostats and distributor cap and rotor. I have also flushed the cooling system and put in "water wetter".

If I'm driving on a cool day it does fine up to 45 or 50 miles per hour.

It seems odd that a fuel related? problem is heat related. Any ideas?

Thanks,

 

Welcome to the forum!

Your fuel lines are likely full of rusty particles. They are the low point of the system and it all collects there. About the only way to really clean it is to remove the line and rod it out, with mechanics' wire, and flushing repeatedly. Honestly, it's best to just replace it.

 

I've found that problem in other cars and it was fuel related predominate in warm weather, here in tri-cities it can be 100+ in summer. The vehicles I worked were daily drivers and not that old. I agree with Ross on the fuel line it's an easier fix than other options. I'm sure someone with more knowledge than I have will help you, just my 2cents. Good luck I hope it's an easy fix.

 

It wouldn't hurt to check float level either. However, if it suddenly changed its likely that there is a fuel delivery problem and/or your main jet passages have gunked up. You can very easily check fuel flow rate (volume/crank time). It helps if you have specs for your setup but a sanity check is good as well.

 

The float level can be very easy to check if you have a glass float bowl.

I would consider vapor lock as a possible issue. If you have older gas it could be more of a problem. This is more of an issue if you live somewhere where it is very cold in the winter...fuel companies blend winter gas to be more volatile. If you filled up in the winter and are still using the same gas this summer, it could vapor lock in a fuel line when the weather is warm.

The problem you describe could, as Ross points out, be related to a weak fuel pump, or partially blocked lines or filters. It is possible that they pass enough fuel at low speeds but not enough for high power operation. The temp thing is a little odd which is why I'm suggesting a vapor lock problem.

Dan

 

THanks All. I'll try some of that stuff. Rick

 

I missed something....your post count...you're brand new to FTE. Welcome to the forum!!

Dan

 

My first check would be to remove the top of the carb and look inside the bowl to see if there is anything in there that does not belong. This is quite common on older trucks.

Then the next check would be to look inside the fuel tank. You may have to slosh it around a bit to check if anything is at the bottom. By all means do NOT light a match to help you see better

I'm assuming that when you said fuel filter you meant you removed and cleaned the fuel bowl at the bottom of the fuel pump?

Good luck. Let us know what you find.