Hello-

I am new to owning my 1968 f100, inline six, 300. It has a 1bbl Autolite 1100 carb.

I have been having a problem lately where the truck is getting harder and harder to start. It seems to start fine when the engine is cold, I pump the gas once, it turns over and starts right up. However, when the truck has been warmed up, I have to hold the pedal down to get it to start, then it smokes, barely runs, and finally idles ok after a few seconds. This happens in varying temps from 60 - 90.

I have adjusted the fuel misxture screw, but not sure if I screwed it up. I have tried adjusting it back and forth but it is still hard to start when hot. What else should i be adjusting? Should I look in the carb barrel when cold for fuel leakage?

Also, sometimes the starter seems to barely turn over, but it finally starts. Is it a starter problem? Why would i have to hold pedal if the starter was bad?

Any help would be great. I am looking forward to learning, as I have heard these are great engines to learn on.
PS- truck has near new motor and full tuneup, was runing perfect when i bought 6 months ago.

Thanks!

Jim

 

Okay slow starter....either timing is off, starter is getting weak, bad cables and or soleniod. Check the cables and cable ends, should be clean and tight. Posts should be clean. Check the timing I believe they like about 10*. Hard starting when hot is either timing or fuel line is close to rad hose and getting hot.
Whoops...welcome to FTE. The 300 I6 is one of the toughest motors ever made once you get it dialed in you will love it, starts easy, runs great and cheap to fix.

 

Thanks 68Torino!

I'll check all the connections to the starter. Battery connections are clean for sure.

As for the fuel line being close to the radiator. I havent moved anyting, and it ran fine before, but the fuel line does run right across the front of the motor. I have alos noticed after I shut the engine off it smells like gas, so I am wondering if the carb is flooding somehow.

I'm all ears for more suggestions

Thanks!

 

CHecked the connections to the starter, selnoid, engine block to firewall, and battery, and everything looks good. I cleaned them as well. I may still have a bad starter.

Timing is on 10* as well.

However, I looked at the carb and noticed when the throttle is pressed, fuel leaks out around the lower front and onto intake manifold. Looks like the carb is leaking somewhere, so I guess I will rebuild it.

Never rebuilt a carb, but I'll try the kit, and if tha doesnt work, mayeb take it to a shop?

ANy suggestions would be welcome.

Thanks for the tips

 

Rebuilding the carb is fairly straight foward. Just follow the directions. As long as it isn't so worn out as to have bad throttle plate shaft(s) you will notice an improvement. Just take your time and look at the carb and diagram if you run into a question. I've done several Ford two barrels, a couple of one barrels and even a Q-jet once in a while.

 

Great, thanks. I bought the rebuild kit, and I am hoping to get it done this weekend. It is an autolite 1100 (1bbl), so i figure i'll give it a try, and worst case i can get a new one for not much.


I was looking at 2bbl, but it isnt worth it without upgrading other things (intake, headers, cam, etc...), and that is too much for now.
I'll let you know how it turns out. Thanks again.

 

You're quite welcome. Just getting the leakage under control is a plus for carbs. The other tricky part is setting the float to specs makes a world of difference.

 

I rebuilt the carb this weekend, took my time, dialed everything in, nad put her back on the truck. It fired right up. I was as giddy as school child

Anyway, needless to say after setting everyting up, I turned off the engine, and noticed the same leaking problem I had before. For some reason, when the engine is off, fuel leaks down inside the barrel, drips on the throttle plate shaft, and runs outside and drips on the manifold.

Reading some posts I have seen folks mention that when the barrel is wet, it may be caused by a bad power vavle. Unfortunately, the rebuild kit didnt come with a new power valve, and specifically stated to leave it as is.

I triple checked the float, and every other measurement. Any other ideas?