Engine running rough after about 30 minutes of use

[Charlie]

Hi
I have a JD450C and it starts runnuing rough after about 30 minutes of use. It loses RPM down to an idle speed and sounds like a spit and sputter sound. Need some ideas where I should start looking for the problem. it started doing this shortly after I drained the fuel tank and added a small valve so I could drain off the water without removing a pipe plug and getting an arm and hand full of Diesel and water.


Charlie

[jdemaris]

Hi
I have a JD450C and it starts runnuing rough after about 30 minutes of use. It loses RPM down to an idle speed and sounds like a spit and sputter sound. Need some ideas where I should start looking for the problem. it started doing this shortly after I drained the fuel tank and added a small valve so I could drain off the water without removing a pipe plug and getting an arm and hand full of Diesel and water.


Charlie

Check the fuel shut off fitting and pipe coming out of the tank. It has a tiny opening and plugs easy. If OK -

Check fuel coming out of your fuel pump. Check with the engine cranking and NOT the hand primer. If OK . .

Pull the timing window off the pump and/or the fuel exit fitting that has the check ball in it. If you find little pieces of dark stuff that look like mouse turds - the plastic inside the injection pump has come apart. $50 fix if you can do yourself and $300-$600 if you let a shop do it.

[Charlie]

Thanks jdemaris
For the reply I will look at those items first thing in the morning. I thought it my be a fuel issue. Thanks again I now have a starting point.

Charlie

[Charlie]

Hi
I removed the line from the tank, opened the valve and nothing came out, I could hear a noise coming from ther tank, so I removed the fill cap and then the fuel came out, not as much as i thought there should have been. Reconnected the line and moved to the fuel filter by the fuel pump. Removed cleaned and replaced. bled the fuel line with the lever on the fuel pump. Moved to the fuel injector and removed the fuel line and turned the engine with the starter and had some fuel but not sure how much I should be getting. ran out of time to give it a run test. Should the fuel tank be vented so it doesn't create a vacuum? my next step will be to remove the tank filter behind the shut off valve. Didn't really want to drain the fuel tank as I have just filled it up prior to it starting to run rough.

Charlie

[tjdub]

Hi
I removed the line from the tank, opened the valve and nothing came out, I could hear a noise coming from ther tank, so I removed the fill cap and then the fuel came out

It sure sounds like you've narrowed down the source of the problem. I don't know where the tank vents (possibly through the cap?), but I know it vents well. I was adjusting my steering clutches once and accidentally kicked the fuel line and cracked that little brass nipple between the shutoff valve and the tank. Let's just say, fuel comes out at a BIT more than a trickle.

Edit: actually, you can see the vent tube inside the filler tube when the cap is off. It vents out through the bottom of the tank. You can clean it out with a piece of wire.

[Charlie]

Thanks Tjdub
I will do that tomorrow, been under the weather for a couple of days.
Charlie

[vestor_guy]

The tank on a 450 does vent through the cap. Make sure you did not install an unvented cap or paint the vent over. If not, clean the vent and blow it out. If I remember corectly, it is about a half inch circle of porus material in the center.

[Charlie]

Hi
I have not been able to work on the crawler, had to go to the Emergency room Tuesday morning, they found a 7 mm Kindney stone, today at 10 they will try and break it up using shockwaves. As soon as I'm able I will check the vent and get back to the board with what i find. Thanks for all the suggestions.

Charlie.

[tjdub]

OUCH! Get well soon Charlie. Hopefully the ultrasound blasts it into a million tiny pieces for you.

My wife had stones many years ago. She was sent to a nutritionist and after some tests they had her make some targeted changes to her diet and take a prescribed (phosphorous?) supplement for awhile and she hasn't had any problems since (knock on wood).

Update: For what it's worth, I checked out my 1967 450 today and the filler cap is NOT vented. There is a small metal tube in the tank next to the dipstick tube that goes out to the the bottom of the tank.

[Charlie]

Well, I got back to the crawler today. I ran a wire down the vent tube thats near the dip stick. It seemed to have a block in the tube.
Took several tries to get the wire thru. I ran it most of the afternoon and it started to lose power and the RPM went to a little over an idle? but I was tired and didn't want to look into the reason why. I also noticed the alt. was not working. So now I have to look into that.

Charlie

[MarkW]

My preferred technique to cleaning obstructions out of tubes is to use a coathanger wire that has been straightened out and then I grind a flat screwdriver blade tip on it, then use it like a twist drill. Coathanger rod is stiff enough to twist but also flexible enough to conform to bends.

Also, when you get your power loss have you tried loosening up the cap to see if the loss goes away?

Sorry to hear about the kidney stones, hope you get back to 100% soon!

[N/E Sooner]

I'm new to JD Crawlers and found this thread while searching 450C's. I have a 1982 450C that has the same symptoms as yours. My injector pump has been rebuilt, fuel pump is new and new fuel filter. Did you ever get yours running good? If so what was the final verdict?
Thanks

[Willyr]

always post pictures or at least tell us where the pictures and some one will help you. We love to drool over other peoples works of art!

[N/E Sooner]

OK here's the pictures.
I just bought my 450C



A couple of yrs ago I bought a new 5083E Limited along with a Z925A mower. The 5083 replaced a smaller JD compact 34 hp tractor that I had for severals yrs.



This last pic is of me and my 7 yr old son (at the time of the pic he was 5)

[Charlie]

N/E Sooner

Sorry I got busy and just today looked at the thread. After cleaning the vent tube it ran for awhile then started loosing power and the rpm went down. I filled the tank full of fuel and after that no more problems. so i think it was just being starved for fuel, I was digging out a place for a building and when the machine was not level I think the fuel in the tank was away from the fuel outlet. the machine seems to be running fine now, but I think I will need a starter before long. I have had to bang on the starter a couple of times to get it to go.

Charlie.