Ok guys I need some help.
For the past two or three days while crusing at various speeds the 300 will start to sputter then clear up. I thought maybe the air/fuel screw had moved so I went and got a vacumm guage and set.
Truck still sputter between 40-60 MPH. Down low it would sputter from a stop if you gave it a little to much gas.
So maybe its running to rich, so I try to lean it out some....same issue.
Yesterday on the way home it was even worse...truck was just sputtering all the way home.
Re-adjusted the fuel mixture and went to sleep.

This AM truck cranks right up, and about 3 miles down the road starts sputter like no ones business. The truck almost seeming to nose dive due to the lack of gas or the extra gas fouling out the plugs.

I pull over get out to take a look and notice that there is water droplets all around the carb, like heavy condensation or something. Very odd so I figure its just getting some water in there and turn around to have my wife bring me in. Not 100 feet down the road the thing dies out. Wont start back up so I sit and wait for about 10 minutes..then she starts right back up..but sputtering really bad..and if I give it gas from idle it has a hard time revving.
The only gear the thing will move in is first gear, with no throttle...or very little to make it up a slight hill. Even then the thing is backfiring, sputtering...and jerking.
I look like a newbie driver. The worst part of it all are the two hills to get to my house........both of which the truck died on...and would not restart...so I had to roll backwards to a flat spot to get a running go at the hill. Finally making it home about 45 mins later on a 4 mile trip.

This problem seems to have gotten worse over time. Perhaps its time for a new carb? I just really dont know enough about them to diagnose these things.
The ingition system is brand new so I know its not to blame. I've had troubles with this carb in the past with the fuel screw going all the way in and killing the truck, but with a new spring on the screw that hasnt been an issue.

Any ideas guys this is my only means of transportation?

 

FYI the local parts store can get me a Holley Reman Unit, or a Champion Reman Unit for the truck.

Which should I look at getting?

 

Have you checked the fuel filter or the fuel pump? Either of them could cause the problem you described.

 

I would hold out on replacing the carb. First do like ranger said. Id first give the fuel filter a shot, thats like $2 and about 3min worth of work. If thats not it the fuel filter in pretty cheap and really easy to replace. The thing that throws me off in this whole equation is the water on the carb thing, i dont know what thats all about.

 

They only thing I could think, it from the dew we've been having here in ga recently...My thoughts where there is to much fuel being dumped into the carb, causing it to be cooler then the rest of the intake manifold....thus causing the dew..but thats just my idea.

The glass fuel filter I have is very clean, and the other on the carb itself is less then 2 months old.
I am a little uncertain however how old the fuel pump is.

If it was the Fuel Pump, would ajusting the carb still adjust how it ran?
What the best way to test the fuel pump?

 

First thing is you need to find out where the water is coming from. Water is your enemy when it comes to your carb, and electical system. This could be your problem. Then next I would have the fuel pressure is. Then you will know if it your pump. Check to see if the water is getting in your distributor cap this can cause problems.

 

i'd check to choke as well.

 

When I pulled over the first time. There was no water under the hood of the vehicle, and shouldnt have been as there has been no rain. The only location there was some slight condensation was around the base of the carb specifically where it attaches to the intake manifold. These were small droplets, but enough where I could see them causing an issue. I removed the air filter and there were no other remnants of droplets anywhere to be seen excepts for directly on the carb.
By the time I got back home this droplets had dried up.

As far as checking the choke. Other then verify the buterfly is not idicating choke, is there something internal on the carb I could check?

 

A late reply!

First, check that fuel filter. If there's any evidence of water in it, that's your problem, most likely.

Most folks don't realize their tanks "breathe" all day long with the warming and cooling of the day. With each "breath" of air taken in, a small amount of moisture is brought into the tank. At night, or when the weather cools, the water vapor in the air condenses on the walls of the tank and drizzles down into the bottom to join up with hundreds of other droplets of water.

That's why grandpa was always so picky about keeping the tank mostly full, especially in the winter...less air in tank, less condensation, fewer water problems.

So, the second thing to do after making sure the filter is not full of water is to get the water out of the tank. How do you do that?

If the vehicle is drivable at all, you may be able to "drive" the water out of the tank. But that is only if the temperatureremains above freezing.

Go to the parts store and get their best gas line anti-freeze containing only isopropyl alcohol. Get enough for four (4) to six (6) recommended "doses". Isopropyl will suspend more water per ounce than methanol, Ive read.

Now, I hope your tank is less than half full. Put a double or triple dose of isopropyl in the filler BEFORE you fill the tank, then fill it with good fuel. (Remember, you are only putting ounces of alcohol into gallons of gasoline. E-10 gasohol is 10% methanol...2 gallons in a twenty gallon tank.) Also, isopropyl is very volatile, use usual fueling precautions with it.

Drive out 3/4ths of the tank before refueling and repeat the above procedure. Then use some sort of product periodically (I use an oil based product that cleans the injectors/carburetor and valves and removes water almost all the time).

Also do like Gramps said and don't leave the tank less than half full for long, and try not to get too close to that "E" mark on the gauge.

 

Check to see than the heat riser tube is connected. Older vehicles used "under-hood" air for intake. Since the early seventies, with environmentally more friendly engines coming out, engines use a mix of outside air and pre-heated air to try to even out the intake air temperature.

When I discovered this on my then-new 1974, I unplugged the vac line to the dashpot that allowed warm air into the filter inlet. It worked fine until the temperature approached 40 degrees one very foggy day. Then my gas pedal started to feel stiff, crunchy, almost. Then the car began to stumble and died. It re-started a few minuted later and ran fine. Back out on the highway the problem happened again.

Then I took off the air filter cover and looked into the carb. I had an ice build-up all around the outside diameter of the carb so that the venturi was down to the size od your thumb...or less! I plugged the vacuum dashpot back in and with a mix of warm and outside air, the car ran fine.

Check that out as well.

 

Interesting thoughts dallbright, thanks for the input. While its no where near freezing here, it has been getting warm in the day 80's and cool 50's at night causing allot of dew, and moisture so I wouldnt be suprised if there was some in the tank.
I just reaplaced the fuel cap the other day. Surely the fact that this one seals tightly wouldnt be causing this issue would it?

I went ahead and purchased a new carb since I wasnt sure how old the other one was. The truck sounds allot better at idle, no more missing idle...nice and smooth.

However!!!!! Dog gone it even though I replaced all the fuel filters. The dang thing is still cutting out.
As soon as I hit the gas, the thing starts to die out...and stumble. BUt at least it idles fine now.
Maybe its my fuel pump not keeping up.

Or maybe I was just thinking the ole pertronix Ign I just got is going out.

 

Check and see if your vacuum advance is working, My truck was doing kind of the same thing and once I got the vacumm advance working it made a big difference.

 

Both of you may be right, fusion and ranger. If the old cap was vented, as they were before evap systems, then the new one could be causing a prob, but probably only after driving a good bit. The tank still breathes in air when you use fuel out and has to allow for heating expansion during the day and cooling contraction at night. Dewey weather...I'm betting there is Some water in there and you don't want that.

Now, the vacuum advance could do the same thing as water...faltering on acceleration...and does it eventually catch up with itself and run at the higher speed...until you put a load on it? I had that happen one time, I believe it was my first p/u, a '61 GMC 3/4 ton with the 305 V-6 (what a monster!). The vac line was steel btw carb and dist., but was connected w/ a short piece of tubing. The truck was nearly 10 years ols when I had it, so rubber parts were starting to dry out and crack. The piece of tubing making the connection at the distributor was maybe an inch long. It took a lot of looking and listening to hear the tiny leak due to a crack right at the end of the metal tube on the distr., but it was just enough to cause sluggish and partial timing advance.

I also fooled around with a distributor once that had vacuum advance AND mechanical advance weights under the cap. The weights were not moving outward to do their job...rust..yep, under the distributor cap. Just a little, just enough.

I assume your base timing advance is set properly and distributor is tight.

Well, sometimes new parts are faulty. Doesn't happen often, but it happens. It's a thought. (Pertronix Ign.)

 

Is there still condensation around the outside of the carb.? Is that heat riser from the manifold shroud connected or missing? That water is bothering me. Still reminds me of the freeze-up.

Does the air cleaner have a snorkel tube connecting it to outside (behind the grille area) air, or do you draw warmed engine compartment air?

Just some more thoughts..........

DA

 

Hey guys thanks for the replies.

After replacing the distributer cap, rotor, and checking the plugs adjusting gap to be .35 across the board. Started her up and she just purs at idle. Took her down the subdivision and as soon as I hit second and give her some gas, she trys to stall out briefly then as you mentioned picks back up.

The other day when I got out of the truck I noticed the vacumm line to the dizzy had popped off. Very odd indeed. So today when I was in the subdivision I started thinking maybe that happened again. I take a look and no issues there. I put the vacumm guage on the dizzy port and tested and she pulls strong vacumm under increased throttle.
With the new carb I havent seen any condensation issues.
I was thinking about the timing being the cause so I actually advanced the timing to 12'. I pulled the vacumm going to the dizzy and the truck actually ran a little bit better it seemed, allot less stumbling under acceleration.
I pulled the distributor cap and I noticed its very difficult to move the plate that the point would normally mount to. Previously when I bought the truck, it seemed that I could easly push this back and forth, but not it seems really tight.

I would take it for another test drive, but as my luck would have it the bolt holding on of the metal brake lines on at the master cylinder decided it would rust itself to the line. So when attempting to replace the master cylinder one of the lines broke apart. So now I get the joy tomorrow of attempting to bend a new line.

Maybe I should spend the dough on a new dizzy its the only peice in the ignition system that hasnt been replaced.

I just hate dumping to much money in other avenues and it end up being a durnt valve or something.


Oh one other thing, when I rev now...she blows black sutt onto the pavement...not a ton but never have noticed this before.

All in all the following things are new

Gas Cap
Dizzy Cap
Rotor Button
Plugs
Wires
Coil
Pertronix Ign
Fuel Pump
Carb