I am a total newbie to owning an old vehicle and bought a 1950 F1 with the orginal flathead 6 in June, so I am trying to learn. I am also not that knowledgeable about working on engines. So with that I will do my best to explain to my problem and ask for advice.

My truck always starts on the first attempt and I usually let it warm up for a minute or two before driving if I haven't driven in a day or two. When I push the choke back in, the idle gets really low and feels/sounds like it could die at any moment. If I let it sit, it will stay running but idles so low you expect it to die, but if I drive it, it will often stall when I come up to a stop and push in the clutch. I find that I either have to press the gas to keep it going or pull the choke back out and let the idle run much higher. I didn't have this problem a month ago.

Anyone have any thoughts as to what may be the problem and how I mite fix this issue? So if someone has any advice, I would be grateful, but know you might have to spell things out a little more since I am not very knowledgeable on working on motors. Thanks for any help anyone is willing to give me.

Thbifeb

 

Welcome to the world of old trucks Thbifeb!

This could be several issues - need to start with the basics. Is there good fuel flow? If the gas line is clogged, the truck will start and idle but may not rev. If the fuel filter is old, replace it. Is the carb clogged? Varnish build up can clog jets. Is the timing off? This would cause the truck to run rough. Is there a vacuum leak? This would cause problems during acceleration.

So, check your fuel line, clean the carb, check the timing, and check for vacuum leaks.

Oh, and post pics!

Happy Motoring!

DW

 

Make certain the idle speed is to specifications. There is an adjustment for this. Tune up recently? Air cleaner serviced correctly?

 

Check the fuel shut off
on the bottom of the cab

mine likes to run at a higher idle rpm also

rebuild carb

Joe

 

Thanks for the info. I will try some of those ideas. I was driving today and was crossing a major intersection and I lost power and just couldn't get the truck to go. It took me a out 30 seconds to cross the intersection and was out in the middle when it went red. No matter how much i pressed on the acelerator, the truck wouldn't go faster. Was going about 2-3 miles an hour in second gear. So, would that give any more clues as to what would bethe problem?

Let me know. Thanks

 

I would look for a plugged fuel filer or weak fuel pump output. Remove the filter and blow through it to check for restriction. They are cheap to replace.then start in engine up with the fuel line stuck in a can.after running it, compare the volume collected to specifications

 

I replaced the fuel filter and that didn't seem to do it. So, how do you clean the carb? I have some carb/choke cleaner, so should I spray some in it? If so, after taking the air filter off, do I spray into every hole? Let me know. Thanks.

 

To properly clean a carburetor, it must be disassembled. Spraying cleaner down the throat will do little or nothing. If you think the carb needs cleaning, buy the correct rebuild kit. To get the right kit, get the #s off the tag that may be on the carb.

 

Initially, the symptoms sounded like a vacuum leak.
Try closing the choke just until the idle speed picks up and see if it runs better. If it does, it is running lean. That can be a vacuum leak or (fuel) idle circuit.
Failure to move across the intersection may be fuel delivery also (as in accelerator pump failure or simply not enough fuel in bowl).
My suggestion is that you should look for a vacuum leak, double-check timing, then verify fuel pump delivery rate and then, if it pushes enough fuel (and it looks clean!!), rebuild the carb.

 

The vacuum line to the wipers frequently gets leaky, and should be checked, but it sounds like lack of fuel to me. If you haven't cleaned out the tank and fuel lines to the pump, sounds like it's time to do it.

 

I hate recommending you run it at all rich, but something I found with my rig... the accelerator pump in the rebuild kit being nitrile was junk went back to the leather. that fixed 90% of my problem. the other 10% richen it up just a touch (I had it perfect on with a vaccuum gauge and it would bog out like that - just a touch rich, and I mean a touch like 1/8 turn it would run fine...)

as always when running out of ideal settings check your plugs to make sure you aren't so far out that issues show up in your configuration.

 

Many of you have recommended checking the vacuum for leaks. Here is something I have noticed, that may give those of you who know way more than I do some more info to potentially diagnose my issue. The wiper will work, but I was driving in the rain the other day and as long as I had my foot on the gas, the wipers wouldn't work. If I took my foot off the accelerator, the wiper would work (not very fast, but it worked). So, does that additional information give anyone a better thought as to why I may stall when pushing in the clutch when coming to a stop or not getting enough speed when in 2nd or 3rd or when shifting between the two?

Again, I appreciate all the help people are giving me. As I pointed out in my initial post, I am not very good with mechanics so I am trying to learn. I have never worked on cars/trucks in my life, so I am about as clueless as they come, but I want to try to learn. Thanks for all the thoughts.

Let me know if anyone else has other ideas based on my vacuum.

Thanks

 

That's normal operation for the vacuum wipers. They sort of work when you are not pulling the vacuum to drive (stepping on the gas) but will stop moving when that vacuum is pulled away to the carburetor.

That said, your problem may still be a vacuum leak.

 

Here's an easy way to find a vacuum leak:

Disconnect or (gently) pinch off vacuum lines such as wipers, brake booster, PCV, etc. Your vehicle may not have all of this stuff. Use a stub of plugged hose or a tubing cap to seal off the vacuum source connection.

Idle vehicle.

Spray WD-40 or similar compound around intake, carb base, distributor vacuum line, etc.

If the engine idles up, you have found a probable vacuum leak.