The Stovebolt Site Forums The Shop Area Engine Shop 216 hard to start...

Need a little help here as I try to get my 3800 on the road again. It's a 1948 216 (pretty sure, at least.) And once it's primed it runs like a champ....

I typically have to say a prayer, cross my fingers, shake my lucky rabbits foot 3 times and then step on the starter.... OR spray a shot of starting fluid into the carb mouth and then hit the starter. The second method is typically far more successful than the first.

Once running it seems to run strong and doesn't die. I've ordered a new rotor and points for it (just figured this was normal stuff that should be done.) The plugs look good and fairly new and the plug wires all look new. The engine is actually remarkably clean!

What else should I look at doing?

It sounds like you're saying it cranks OK but won't fire without using ether. Is that correct? If so it sounds like it needs a carb rebuild to me.

Cranks great but won't fire easily. If I jump it with 12v it seems to fire easier (but still not perfectly.)

Once it's warm it starts great on its own.

Are you using the choke? I always use the choke and it normally starts within seconds.

Choke on or off doesn't seem to make much of a difference until it's actually running.

For years, if my truck sat for 2 or 3 days without running I would need to pour a little gas down the carb to get it to go. I replaced the fuel pump, and more importantly I think, the Rochester carb for a Carter 2100s carb.

Start like a dream now.

Kurt

Hi, 48bomb, You may be use to a fuel injected car that has a ECU(engine control unit). On these old trucks, You are the ECU. What I do to cold start my 49 216 is pump the gas pedal 2-4 times and then with full choke I put the toe of my right foot on the starter pedal and have the heel of my right foot over the gas pedal and then push the starter pedal. When it tries to start I hit the gas pedal with my heel and at the same time release the starter pedal. As soon as it starts I push the choke in about 1/2 way, and then adjust throttle and choke as required until it will idle, then drive away. Have fun.

It's an art!

have you pulled the carb apart ever? Ive had a lil screw loosen up and fall into the bowl causing it to run funny

I know on my rochester b if i work the throt shaft and see it get moist, there is fuel ready to fire, I also have a visible filter before my fuel pump. if the filters dry i can assume that its gonna take a crank or 2 to get the mech pump to get the fuel going again.
Do you have a mech or electric?, that would be one way to ensure you dont have to keep cranking it. I just have a mech a vis filter

Here's a photo of the carb and it probably is due for a rebuild (looks like a leaky base gasket at the very least.)

http://i635.photobucket.com/albums/uu79/rbosworth/20121010_082302.jpg

Rochester is stamped on the carb. Anyone have a part# for the rebuild kit? Is it something NAPA might carry?

And yes, I'm sure that this won't be as easy to start as anything modern but I've got at least 5 vehicles that are carbed and none of them are as big of a roll-of-the-dice to start as this one is. They all require a bit of cranking but then will fire right over.

If the engine is well-tuned and the carburetor is right, it shouldn't be necessary to do a Mexican hat dance on the pedals to start a cold engine. Pull the choke full-on and crank. As soon as the engine fires, push the choke in about 1/3 and let the RPM's come up a little, then slowly wean it off-choke as the engine warms up. If it won't do that, you need to tune the ignition system and/or diagnose any problems with the cranking speed or the carburetor. If the choke isn't closing fully, it will be very hard to start when cold.
Jerry

I had a problem with the check valve in the fuel pump. I think the fuel would drain down after a while. That combined with evaporation and a leak or two resulted in no fuel in the carb. It would reliably start eventualy with enough cranking and pedal work but I found it easier just to dump a little gas down the throat.

Kurt

How does the fuel from a Rochester one barrel carb drain back through the fuel pump to the tank?

Going through the tune up should have corrected this but be aware of a modern day trap caused by using spark plugs "out of the box".Most modern plugs are shipped with too wide gap--a sure recipe for hard cold start.With out exploring the reasons, let me simplify by reminding to check for the PROPER gap for the old ignition system.

Roy,

I think what happens is that after the truck sits for a few days, the fuel in the bowl evaporates enough to open the float valve causing a vacuum break and then the fuel in the line can run back to the tank because of a faulty check valve in the pump. Then you have to crank the engine -a lot- to recharge the fuel line and the bowl. Then she will fire up no problem.

I never had a problem starting the truck after it sat a day, but after two or three days it would take a lot of cranking or a bit of gas down the throat.

Just a guess, don't really know. Putting on a new fuel pump and a rebuilt Carter carb sure fixed the problem though.


Kurt

The check valve in the fuel pump lets the fuel drain back. Install a new fuel pump and things will be much better.

The fuel evaporating from the bowl is exactly right. There's actually very little fuel in the line, and since the fuel pump is about the same level as the bottom of the fuel tank, it can't really drain back very far.

Also, there is air in the carb between the top of the fuel level and the needle seat, so the fuel can't siphon back out of the carburetor. It will evaporate after a few days, and will have to crank it over a few extra licks to fill the bowl back up, but it can't siphon back to the pump. And what little will be in the line between the pump and the carb won't go far.

If the fuel pump is weak it may take quite a bit more cranking for it to catch up, so I can see where a new pump would help.

Another thing that would help is if the gasoline we get were better.

Kurt, replacing your carb with a Carter was likely the real fix. The poor old Rochester one barrels just aren't as good.

Roy, I know the fuel can't siphon out of the carb.

The rochester carburetor actually ran the engine well other than being leaky and inefficient. That's why I replaced it. I replaced the fuel pump because of the problem with starting. The burb tank is under the floor, and I'm pretty sure that most if not all of the tank is below the fuel pump. I'll take a look next time I'm under there and let you know for sure. Maybe you are right.

Bottom line is that today I started the burb after it had sat a week (its been raining) with only a few licks of the starter. And that's what I'm talkin' about!

Kurt

Roy,

For what it's worth, I did go out at lunch and check the level of the fuel pump and top of the gas tank in my 'burb. The fuel lines at the pump are 26 inches above the ground, and the TOP of the tank, with the truck unloaded, is 25 inches above the ground.

So I'm still thinkin' my gas was draining down to and maybe through the pump. I'm guessing the pump would loose prime, and this is why it would take so much cranking or a squirt of gas to get it to go after it had been sittin' 3 or 4 days.

And I don't feel like putting the old pump and carb back on to do some scientific experiments LOL.

Kurt

Yes sir. But there are a few that have the mind set the fuel is being pulled from the carburetor and going back to the tank.

And a good fuel pump does do wonders.

Alright -- Checked some things out last night. Bought all new spark plugs, rotor, cap and points only to take my existing stuff apart and find that they were also all brand new. Nice little surprise on a "roller" that I paid $1000 for.

Checked the points gap and gapped the spark plugs per the manual.

Took off the glass filter bowl and found that it was filled with junk. Gave this a good cleaning. I've got a late-era inline filter closer to the carb that I'm going to swap out.

I've got some questions about the glass filter, though -- how does this thing work? I assumed it had to be filled with gas for the engine to start so I unplugged the distributor and cranked the starter for quite a while expecting the bowl to fill up. It never did but after reconnecting the distributor I was surprised that the engine started right up and after about 30 seconds the bowl slowly filled.

I think my next step will be a carb rebuild.

There appears to be RTV between the carb top and body. If that is the case you need to pull it apart and see what else is wrong!