bad fuel pump?

Hi,
When my 225 is not run for like a week it is hard to get started. It's like this- pump gas twice, crank 10 sec, pump gas once, crank 10 sec, stop wait a few sec, crank 10 sec, pump gas once or twice, crank 10 sec get a little fire, dies, pump gas twice, crank 10, begins to start, dies unless pumped a few more times. If it has just been run, it will fire up immediately. I'm wondering if the fuel is draining all the way back after sitting for a long time?Or if something else is wrong? It runs good after it gets going. It has a new carb and new timing chain, I set the timing on 5 deg before (Delco). Maybe idle is set too low? Ideas?- seems like a lot of cranking to get started.

Josh

 

I've had trouble with the float bowl (2G) going dry. I have never figured out what causes it & it's not doing it now. Has happened several times.

The first time it happened I changed the fuel pump even though the old one was only a year old - that wasn't the problem. I also changed the brass filter at the carb inlet 2 or three times - that wasn't the problem.

It's easy enough to take out the screws on the carb lid and check the float bowl. If it's dry at least you'll have a place to start.

If anyone knows why/how the bowl goes dry feel free to post.

 

Boiling?! You could be right but it has happened even when the motor didn't get real hot - like a 5 minute trip up to the mail box IIRC. It's been awhile since this has happened so I could be wrong on that.

Just thinking - when removing the top of the carb to look I was supprised by just how dry the float bowl was. You know how a pan of water left on the stove until all the water is gone looks? That's how it looked.

Sparky, you're a genius.

If this happens again, what's the cure? Is there such a thing as a carb spacer?

 

I have the same issue. I have a clear filter in between my pump and the carb, and if it sits for a while, (week or longer) the fuel drains back down inside the tank. I think in my case its because my tank is not vented and when I shut it off I can open the cap and hear it suck air back into the tank. I have a return line running from my pump back into the tank to return excess fuel. When I vent the tank I done have the same problem. Is your tank vented?

 

Yes, my fuel tank cap is not air tight so the tank is vented through the cap.
So you're thinking the fuel doesn't leak into the carb or evaporate, but instead it runs backward through the fuel line to the tank. I guess you (or I) could install a fuel shutoff valve to find out for sure. I'll keep that in mind if the problem comes back.
Josh - sorry for taking over your post!

 

I actually have a shutoff valve. I never use it unless I'm disconnecting the line or something.

 

I don't believe that is possible; The fuel bowl is fed from the needle/seat which is above the fuel bowl;even if the bowl were full of fuel, it could only siphon so far.
I think it's just heat soak..... engine heat causing evaporation in the fuel bowl.

 

I know we started talking about Josh's 225 here but I had this "boil out" problem with my F134 couple times and so far have not been able to find a thick spacer/insulator gasket to go between the manifold and the YF carb. If anyone knows where to find one, I'd appreciate the lead.
Searched the local auto shops and can't find anything listed for modern 1 barrel carbs.

For Josh, I wonder if you have a leak in the suction side of your fuel line (between fuel pump and tank) that's letting the fuel flow back into the tank while its not running. If the leak is just a pinhole and is high enough relative to the tank, you'd never see any fuel. Unless it gets air some place, its not natural for the fuel to flow out of a small closed line.

Eddy

 

Eddy
try stacking the gaskets
not the best way, but we are experimenting here
no more than 1/2" should do the trick
tell the FLAPS guy you want to go thru his carb gasket drawer/cabinet
Big A/ Carquest is who I had good luck with

 

Thanks Jim, hadn' t thought about stacks.
Eddy

 

Should be able to make one without much difficulty. I believe the material is phenolic, and you should be able to buy a scrap from your local plastic supplier. I'd try making one out of a couple thicknesses of tempered masonite, glued with waterproof glue and coated with urethane.

 

Facinating. But I still have no clue what to look for.

Josh

 

Sorry Josh, the instructions in the last two replies above were for me (thanks guys). I was looking for a gasket/ insulator to solve what we think is heat soak or fuel boil out on my f134.

From your descirption I don't think thats your problem. I wonder if you have a leak in the suction side of your fuel line (somewhere between fuel pump and tank) that's allowing the fuel to flow back into the tank while its not running. If the leak is just a pinhole and is high enough relative to the tank, you'd never see any fuel leaking. And if its a pinhole in a rubber line, it may pull closed under vacuum and that explains why it runs at all.

Unless it gets air some place, its not natural for the fuel to flow out of a small closed line.

One way to check this is with the line known to be full of fuel, put a little air pressure on your fuel tank and look for a small fuel leak in the line between the tank and the fuel pump. Don't use a lot of pressure you don't want to harm your tank, couple of psi should do it.
Eddy

 

You can try a little experiment. When you let your Jeep sit for a week, instead of trying to start it up normally, pour a little gasoline down the carburetor first. Not much, maybe 1-2 tbls full. If it starts right up and then dies, your float bowl is dry. Or, you can take the top off the carburetor and look at the level of the fuel in the float bowl after it sits for a while.

Ideally, a carburetor should keep fuel in the float bowl for a few weeks, or even longer. If the bowl is dry, it's probably evaporating somehow. This can be caused by leaving the air cleaner off, or (I suppose) even by using an open element air cleaner. The gas could also be evaporating because the carburetor top doesn't fit right, or the gaskets are damaged. The float bowl is supposed to be like a cup that holds the gas in the carb, ready for starting. The carburetor top and air cleaner are a cover of sorts for that cup, preventing the fuel from evaporating. If the float bowl is dry, it needs to be refilled by the fuel pump before the engine will start. This is why it takes so long to start the engine when the float bowl is dry - the engine has to turn over enough times to draw fuel from the tank and send it to the carburetor. This is usually 20 or 30 seconds of cranking.

hth

 

Josh,
Let us know which if any of these suggestions you find to solve this.
Eddy

 

Alright, I'll have to let it sit for a while then.

Josh