Pulling the fuel filter shouldn't be too difficult once you're able to get your hands on it. If a new fuel filter doesn't help check the gas cap to see that it is not plugged. You might try running an injector cleaner through as well. Mix some into the gas and pour some straight into the throttle body.

johnsinva,

Once I put the new fuel filter in it ran fine. I'm surprised a fuel filter made that much difference.

I retract my last statement. When I started it cold today it was surging again. What do I replace next? Fuel pump? Do I just take it in to the JD dealer?

They are weeks behind. It's going to be rough around here without a tractor for two to three weeks.

I have a JD325 W/20hp Kawasaki that surged, I ended up taking it to JD and they had to work on the Carb. I guess they are kind of sensitive. It took care of the problem. I can't remember what was exactly wrong.

it is a jd345 not a 325

We have a similar surging problem with our jd 445, which is worse as the engine runs for a longer period. What was the source of the problem?

Spray the carb down with carb cleaner and see if that helps. I had to take my carb off and give it a good cleaning to solve my surging issues (from sitting over the winter).

jkb,

sorry I never updated this thread with the solution. Through a friend I found someone who once owned a JD dealership, but now just serviced them. He spent a lot of time going over it and doing tests which showed everything to be working ok. What he did find was two inches of hose on the pressure side of the fuel pump that was cracked and leading fuel back into the gas tank.

When the hose leaked the line lost pressure and it was starved for gas. If the crack held it ran fine. I suppose also the pressure would build and the crack would open which released the pressure and closed again. Thus the surges.

It's been running great ever since that two inches of black fuel hose was replaced.

Thanks for the responses. I tried stp fuel injector and carb cleaner to no avail. The problem has gotten worse with the engine barely starting and then cutting out without being able to rev up or even continue running. The cycle repeats when restarted. I hear the fuel pump run when the key is turned, and the gas cap breathes okay. Hopefully the hose is the issue, next to figure which one that is. From one of the other threads it sounds like there is a process to avoid pressurized gas from spraying, but if it is a cracked hose, perhaps the pressure will have been relieved?

I believe it was in the gas tank connected to the fuel pump. I don't know if it relieves all the pressure?

It will be the hose leading FROM the tank TO the fuel injector body. If the hose in question does in fact have leakage inside the fuel tank, there will be no pressure in the hose. You need to find a diagram describing which hose is connected to the pump, or you "might" be able to shine a flashlight into the tank to see the pump and hose for positive ID. The pressure is supposed to be "held" in the line by the fuel pressure regulator valve. The "pressure regulator valve" is situated in the "return to tank" circuit of the fuel system piping. The pressure regulator maintains a "head of fuel pressure" in the side of the fuel plumbing where the injector(s) are. This pressure is what "shoots fuel" out the injector nozzle during injection. If the pressure hose leaks right back into the tank from the line on the pump, you have lost both pressure at the injector, and volume of fuel as well. The symptoms could even mimic a clogged fuel filter or a pressure regulator valve that is stuck open, or has a defective "pressure spring". It is always a good idea to wear safety "goggles" of face shield whenever you work on fuel systems. Even if you don't get sprayed, a splash in the eye is painful and/or harmful. And No Smoking, please.

I suspect the ethanol that is now widespread in fuel is causing that short hose between the pump and the hardline on the bracket to split and fail. Remove the fenderdeck and take the fuel sender/pump bracket out of the tank to check.

That's some good detail mownie. I think I'll print that out and put a copy in my manual for future reference.

I have the old hose here in my hand. 1 13/16 long. 1/2" outside diameter, 5/16 inside diameter. It is very hard. Takes a strong hand to squeeze it to reveal the crack.

Thanks, pay attention to engine_tech. He's been around the EFI block a time or two himself. :^)

Thanks again for the responses. The short hose was the problem. Nice work from afar!