1984 F-150 302 Windsor 2WD - "Old Red"

If the lines does drain back to the tank, I cant see all the fuel in the line doing this but maybe some of it.
If there is fuel in the carb bowl it should fire right up and the pump would then pull the fuel from the tank.

What happens when sitting a few day and more the fuel in the carb evaporates and why you need to crank and pump the throttle till fuel fills the bowl. If it sits over night it should start with a pump of the throttle or 2 and fire up and run if the choke is adjusted right.

As said mine may sit for a week between trash runs and I will need to crank it a lot before it fires up.
Once running I dont need to let it warm up but I also have a stick trans and the choke is adjusted pretty good. If mine is started / driven every day just 1 pump, tap the key and it is running.
Dave ----

That was my thought as well. I've had some starting issues the next morning as well. When I've pull the air cleaner off to check the choke plate (prior to any cold starting) it's ~90% closed.

Maybe it is my choke, all my starting issues are when the truck is cold after a day or so - after the first pull, it starts great and instantly all day long.

If the truck has been sitting a week, I feel like I'm cranking it until the battery is going to run out of juice, eventually it'll catch and then idle very poorly and want to die if I try to feather the throttle.

The only thing I know needs replacing is the tank selector valve...from there I'm scratching my head.

JMUBullnose wrote

That was my thought as well. I've had some starting issues the next morning as well. When I've pull the air cleaner off to check the choke plate (prior to any cold starting) it's ~90% closed.

Maybe it is my choke, all my starting issues are when the truck is cold after a day or so - after the first pull, it starts great and instantly all day long.

If the truck has been sitting a week, I feel like I'm cranking it until the battery is going to run out of juice, eventually it'll catch and then idle very poorly and want to die if I try to feather the throttle.

The only thing I know needs replacing is the tank selector valve...from there I'm scratching my head.

The choke may need a little adjusting but first I need to ask.
If sitting over night or 1 day how many times are you pumping the pedal before trying to start it?
Also how cold has it been when trying to start it?
I would say if the temp has been say 70*f and you are only pumping it 1 full to the floor and let up try 2 pumps and maybe 3 then nold the pedal down just a little. The colder it is the more pumps but I would not think it should need 3 pumps.

If that dose nothing even with 3 pumps and a little throttle then you need to check both the choke and if the throttle is squirting fuel when moved.
If it is not squirting that needs to be fixed first then if it still is hard to start the choke.

If it has been sitting for a week where you know you have to crank it a lot I crank it and keep pumping the pedal as fast as I can till it fires up. I will stop after a few seconds for the starter to cool off then do it again till it is running.

My truck only needs 1 pump when it sits overnight in a warm garage and maybe 2 pumps when cold out and it sits at work for 12+ hours.
I grew up with carbs and many different make cars, trucks and motors so this is nothing new to me.
Thing is you just need to find what your truck need to fire up.
Dave ----

Great questions - thank you for commenting!

If the truck has been sitting over night or 1 day, I'm usually pumping the pedal 1 time. I haven't done anything empirical comparing 1 v 2 pumps of the pedal (yet).

Temps - we're still in a pseudo summer here in the Mid-Atlantic so temps have been between 70-85. I'm assuming that once winter does arrive, I'll need to some adjustments to the choke for cold starts (winter starting has always been an issue for this truck...that's another lay of the onion as Gary likes to say).

I keep getting close to progress and then life gets in the way (I mean, look at the gap in time between my last updates on this truck and today! )  

When the carb was rebuilt - I know the gent that owns the shop also replaced the power valve and accelerator pump diaphragm. Don't get me wrong, when the truck is running - it's running the best it has in a couple years. I know it could be better though - if I can get it to point where a couple pumps of the pedal and starts after some cranking I'll be happy.

So I'm off this week as I switch jobs - decide I'm going to spend some time on the truck and see if I can't make it more reliable to start.

I adjusted the idle mixture screws as the truck has been really rich when idling and the screws felt a little loose, like they had backed out from the previous setting. Re-baselined by screwing them in all the way and then backing out 1.5 turns like rangerstations's rebuild guide mentions in the tuning section. Got the car started (this has been challenging as of late - had to use a squirt of ether to get it going). Then allowed the truck to warm up and idle. Once nice and warm I adjusted the screws out a little more to even out the idle (making sure the screws were backed out evenly). Everything seemed great, truck idled for ~20 minutes or so just to top up the battery while I puttered with other things.

Jump in the truck after putting all my tools away (condo - can't just leave them in an orderly fashion next to the parking space), put it in drive and make it all of 30' before it just dies without warning, didn't even stumble - just silence.

Couldn't start it - would only turn over 3-4 times and stop. I checked the battery voltage, 12.4V with the truck off. Pushed it back to a parking spot and was able to get it started again with a quick hit of ether. Adjusted the mixture screws out a bit more since it seemd to be stumbling and it evened out. Once I had it even suddenly it just died again while I was standing in front of it. Throttle lever just kicked forward and truck died.

This time it restarted right away and kept running. I was able to move it in both drive and reverse (and get it back into the spot it usually sits in). Unsure what's going on, it started to not want to hold an idle again and I could feather the throttle to keep it running.

After the last shut off, I could hear oil draining back down into the pan - which made me check the dipstick. Low- so I'll add some oil there and check to make sure the coolant is good to go. But other than that, I'm at a loss. I also noticed that with a very warm engine the butterfly was only 1/2 - 2/3rds open.

What have I screwed up by monkeying with this thing?  

One possible explanation for that kind of behavior is small crud getting into passages in the carb. How old is the gas in the tank, the sock, the tank, the fuel lines themselves, and what's the filter situation?

Hey Pete -

Great question. Gas in the tank is fresh. I end up driving it one way or another every week or two and probably fill the tank once a month. Prior to me getting the bright idea to monkey with stuff today it was running just fine - just really a pain to start.

Soft lines from the tank to the selector valve are 6 months old.
Fuel filter at the carb is probably 2 years old or so.
Carb was rebuilt this past summer by a local shop (well, local to my folks - I haven't found a shop like that here in our new home yet).

You may have dislodged something when you moved the needles.  On an Edelbrock I blow out the idle passages with compressed air, but on your carb you might damage the accelerator pump or the power valve, so I wouldn't do that.

But, how far out did you finally get the screws?  I'd think they would be around 2 turns out, and if you didn't get them that far I'd open them up a bit and try, then open up more and try.  I think you are just way lean.

Having said that, I'm going to ask Bill to come help with this.

Gary - it's funny you mentioned the screws. I was about 1.75- turns out. Finally pulled out the vacuum gauge and hooked it up to line going from the manifold vacuum to the PV on the carb (finally decided my vacuum routing!)

I after a bit of fiddling it would seem that I needed to be about 2.5 turns out on both screws. They were about 3.5 out when I decided to re-baseline them. Reading right around 20 on my gauge now - I almost feel like I know what I'm doing!

Waiting for the wife to get home so I can check the vacuum under load. When I sat in the cab and put it in drive - engine wanted to stall out until I feathered it. So, likely that I've got another slight adjustment to do.

You said it was running quite rich, have you pulled any of the plugs to see what they look like? Part of what you describe sounds electrical related "shut off and the throttle went forward" that would indicate a loss of electrical power to the idle solenoid on the side of the carburetor. Since it is fed by the same source as the ignition system, that may be your problem.

With it running, try slightly turning the key slightly back and forth, if the engine shuts off with very little motion towards "off" I would suspect the ignition switch, particularly if is the original or even just plain old.

Good point, Bill.  I caught that bit about the throttle going forward, but hadn't put 2 & 2 together that the throttle going forward was the cause of it stalling and not the other way around.

Throttle going forward is indicative of loss of ignition system power, which by itself might not kill the engine as it is most likely an anti-dieseling solenoid.

85lebaront2 wrote

With it running, try slightly turning the key slightly back and forth, if the engine shuts off with very little motion towards "off" I would suspect the ignition switch, particularly if is the original or even just plain old.

Thanks Bill - I'll have to check that tomorrow morning. The ignition switch itself was replaced about 1.5 years ago by the same shop that did the carb and my headlight switch. Always worth a check!

I was doing some searching trying to see if I could an NOS or OEM dashpot solenoid as mine looks a bit tired. No joy so far. (e2ae-9s520-ab)



That's the first time I've ever really had the truck just die like that too. If I feather the gas a little bit it eventually catches idle again and holds.

So, embarassing question time - where is the warm idle set screw on the right side of the carb? Is it the little slotted set screw behind the plate that meets the plunger from the solenoid? Or is it the threaded bolt that adjusts the position of the dashpot solenoid? It's been so long since I monkeyed with the carburetor that I can't remember!

It is the threaded bolt that slides the whole assembly, but there should be a screw through the base of the carburetor behind the throttle shaft, that is used to set the minimum idle, primarily so the throttle plates don't stick. The small slotted screw in the lever is a "don't mess with it" it is for the TV rod to your AOD transmission.

I know this might seem simple but how about any cracked or missing vacuum caps. "rubber these days". what Ya gonna do?

85lebaront2 wrote

The small slotted screw in the lever is a "don't mess with it"

Well...poop. Without thinking I did move it but am pretty sure I have it close to where it was before.

Specifically adjusting that idle screw - I might tighten it up a bit to raise the warm idle if this continues. The solenoid really doesn't seem to be actuating.

mat in tn wrote

I know this might seem simple but how about any cracked or missing vacuum caps. "rubber these days". what Ya gonna do?

Great point. I went over everything vacuum related the other day while trying to figure out what the one nipple on the back of the carb was for (air to the heated choke assembly if you have that apparently). I didn't notice anything but it is always worth a look! (There are a couple lines that were capped off my by grandfather and his brother - I have no idea what they go to. More time with the vacuum digram should help)

Been a bit but I finally moved into my house so the truck has a proper home again. Now to unpack boxes and actually find my tools so I can work on it.

Adjusting the fuel/air screws with a vacuum gauge has helped tremendously when it comes to the truck actually running.

However, cold starts are still a problem. Even after sitting just one night - it's difficult to start the next day. I'm worried about the number of times I've had to use some starting fluid to get it to fire off and start.

Things I've tried:
-When it has been sitting for several days (up to a week) - 4x or so pumps to the pedal to get fuel to the bowl. No joy. (I can't remember who on here suggested this to me)
-When it's been 24 hours, 1 or 2 pumps of the gas pedal to start it. Sometimes I get a quick almost start but usually no joy.

One thing I'm glad to note is that the power drain I thought I had going on was actually due to the solar tender I put on the truck to keep the battery topped up during longer sits.

So, I'm at a loss as to next steps. The engine is cranking strong off the battery and I can smell gas after a few cranks but no joy on the engine firing. I checked the choke prior to my last cold start and the butterfly was about right in terms of how closed it was. I'll get a gauge/drill bit (3/16"?) to double check the choke setting.

I'm now trying to drive it 1x a week at least to keep it 'exercised'.

This is a subject in another thread right now as well.
Basically if the fuel evaporates from your float bowl cranking the engine (to get the mechanical pump to prime the carb) is the only answer, short of filling the floats manually.
I have to do this if I let my truck sit for long enough.

Is your charcoal canister and purge valve connected to the carb breather?

So, that's good - you've confirmed what I assumed is happening. Cranking the engine causes the manual fuel pump to cycle and draw fuel to the carb. That also jives with smelling fuel after a few (3-4x) 15 second cranks.

On the charcoal canister and purge valve...I actually don't think it is connected to the carb.

I only asked because a disconnected EVAP system makes it easier for the bowl to dry out. (vapor pressure and all that)
It happens to my truck sometimes, if I neglect it.
A 60cc syringe of the tru-fuel I keep for the mower down the standpipe has the truck starting right up.