Y385T - Fuel delivery problem

Tush67 · Mar 8, 2015

Hi from sunny Wales. Well not that sunny really but we live in hope.

Small problem I hope you might be able to help me with.

I had a problem with power reduction which I thought might be due to faulty injector. Turns out it isn't.

I've removed all the hard fuel lines from the pump and I can get fuel squirting out of 2 when I crank the engine. The one not working serves the cylinder closest to the steering wheel. Took off the delivery valve holder, valve and the spring...no obvious problems there. There's plenty of fuel spurting out when I crank the engine without the holder, valve and spring but when I assemble it it just won't squirt like the other two. Tried switching the holder/valve/spring but the problem persists on the same cylinder. (The one I swapped it with works fine, supporting the view there's nothing wrong with the holder, spring and valve.)

Any clues? I'm going to lose all my air if I scratch my head for much longer on this one.

Thanks in advance

Bob Rooks · Mar 10, 2015

If you swapped out the barrel and plunger assemblies and there is no difference, and you say all the injectors are "good", then there is only one explanation. That cam lobe in the injection pump is worn to the point where it isn't lifting the plunger. That's pretty unlikely too. Did you try swapping injectors? Did you have the injectors pop tested?

Tush67 · Mar 10, 2015

Thanks for posting a reply Bob.

Tractor only has 100 hours on it so likelihood of a cam lobe being worn is highly unlikely. Cam is obviously turning too, or the other cylinders wouldn't be working. Wondering if there's a way I can turn the cam manually with my finger on the delivery valve where the problem is to feel how much it lifts?

Think I probably need to flush diesel through the delivery valve hole in the pump (with the valve out) just in case there's something moving around blocking the flow. Flushed plenty through at the weekend mind, mostly onto my jeans. (Note to self - leave it a while longer next time before having a cigarette when doused in diesel!)

Got a new injector for the cylinder that wasn't firing. That said, there's a remote chance that's faulty I suppose so I will swap them over and check it fires on one of the two working cylinders, just for completeness. That won't resolve the fact that fuel isn't getting past the valve/valve holder for the failed cylinder.

Good job I spend my life tinkering with British motorcycles...it teaches you patience!

All the best

Bob Rooks · Mar 11, 2015

I pop test brand new and reman injectors. You'd be amazed how many bad ones turn up.
Nope, there is no way you can turn the cam by hand.
I was assuming (my bad) that you have checked the valve lash. Is that okay? Because that will cause a decrease in compression, and that cylinder won't fire (compression ignition engines).

Tush67 · Mar 11, 2015

Cheers Bob.

Valve lash seemed okay (no discernable difference between all the inlet ones or exhaust ones using the touch test) but when I put it back together I will get the feeler guages out and check properly.

Be a day or two before I can work on it again but when I do I'll go through all we've discussed and fingers crossed it will be purring again by the time I've finished. I'll let you know how I get on.

All the best

SPIKER · Mar 11, 2015

I had to get my 284 out to push my car out of the MUD (was going to pull it into the3 pole barn to swap out the Studs) all 4 tires peeled up the grass and wrapped it around the tires like a SOD machine. Well one that only made it 15 feet before it sank 6' into the mud...

When I scooped up some SNOW to use as a cushion on the FEL to Back Bumper and pushed the car out I had to shift into L3 to move the car. I've been noticing a slow loss of power last fall and this winter but will have to investigate farther. Will keep eye on this for more thoughts.

Mark