The Art of Delivery, fuel'd with questions...?

[TBDonnelly]

First thing that comes to mind is that it might be thermally related. Could an electrical part be changing after warm up (like a solinoid), or some sort of expansion caused by heat, maybe causing air to be drawn into the fuel line? Perhaps fuel pump or relay? Or even hydraulic pump, if it only happens when operating hydraulics.

I have not looked into anything electrical and have focused totally on fuel and it's delivery. On a side note, my previous tractor was a 1990's vintage Ford 17hp and my first diesel experience. A mechinac told me to never let it run out of fuel because it would be very difficult to restart the engine. So........ eight years and 600 hours later I never had changed the fuel filter for fear of not being able to get the tractor started!

"....causing air to be drawn into the fuel line? Perhaps a fuel pump or relay?" Hmm........... Now I'm looking at the fuel pump. I pulled the fuel pump and taking a deeper look. Allow me to get some pictures of the fuel pump and I'll return...............

I don't think it's hydraulic specific because it happens with just the tractor and no hydraulics in use.

Or it could be the infamous injector pump dieing a slow death. Mine behaved this way for a while. Then it started to run uncontrollably wide open. Your hours are right about where mine were when my injector pump failed.

I'd check the flow of fuel at the point where it enters directly into your injector pump the next time it happens and make sure it is as expected. This will either confirm or deny that it's related to fuel delivery (at least up to the injector pump).

I'd be surprised if it's exhaust or intake related. I would think those sorts of issues would be manifest from first turn on.

I'll be back with more pictures......

Don

 

[TBDonnelly]

Not sure what they use to control the fuel pump. With that said, check and clean ALL of the ground connections; ignition, battery, pump, etc. One of them is probably loose and/or corroded.

Fuel pump is not electrical.....

Don

 

[TBDonnelly]

Different views of the fuel pump. I'm not seeing anything torn, broke or bent. Comment?

Don

 

[Highbeam]

Fuel bowl was half full, the other half is air, you are getting air in the system and sucking air into your injection pump is going to make your engine run poorly and die.

You have an air leak upstream of the filter.

 

[IslandTractor]

After the most recent occurence, just a couple weeks ago, when I limped the tractor back to the garage, I looked at the fuel bowl and it was only 1/2 full of fuel.

Well, of all the symptoms and signs you have posted, having a fuel bowl half empty certainly stands out. Is there a leak or crack in the fuel bowl? Is there blockage upstream? I'm no mechanic but I'd say you have pretty clearly established that this is a fuel supply issue at this point.

Now for those experienced diesel mechanics out there, what are the reasons that a fuel bowl could be half full?

 

[EddieWalker]

I had a jeep that would run great when you started it up, but after awhile, it would lose power and could barely get it above an idle. Turn it off, let it sit a few hours and it was good again, but after awhile the same problem would happen.

After running out of ideas and trying everything that I could think of, somebody suggested that it might be my exhause system. If it gets pluged up, or has some restriction, then it could make it worse the longer it's driven, but it wouldn't be noticable right away.

I replace the muffler and catalatic converter and solved the problem.

My backhoe started having lack of power issues. I cleaned out the sediment bowl, and that helped, but it didn't fix it. I repalcedthe filters, but that didn't change anything. My Dad showed up and thought to blow out the fuel lines. We took them off and blew them out with the air compressor. I didn't notice anything come out of the hoses, but I could have missed it too.

With the hoses back on, it ran great. Problem solved.

Eddie

 

[RobS]

Here's a long shot... Perhaps the heat, after extended use, is softening up a rubber fuel hose which is then collapsing under the suction of the pump?

I had some loss of power problems with my tractor and it was all fuel filter. Gelling/wax could be a culprit but you mentioned both warm and cold weather problems.

I'd be inclined to rule out electrical as that would most likely be an on/off situation.

Spark plug wires? Oh yeah...

 

[o2batsea]

Loss of power with a diesel is 99% of the time fuel related. When it loses power that means the engine is not getting fuel somehow. Whether it's a bad pickup pump, a faulty distributor pump, blocked supply lines, blocked return lines, jacked up injectors or contaminated fuel must be determined before further trouble shooting. If it runs well at first and then starts to act up, you can eliminate the air supply and exhaust questions.
There are tests you can perform if you feel comfortable doing them. It would involve removing the fuel lines one by one from the supply pump then the distributor pump to see if there is air present in the flow. You have to submerge the open end of the line in clean diesel and crank the engine, checking for air. This can be a pain if there are hard lines from the diz pump. Usually it is a good thing to make up a test line that can be fixed to each of the outlet ports of the diz pump being long enough to reach to a jar.
It is most reasonable to assume that the system is sucking air somewhere between the tank and the diz pump, although a faulty injector can't be ruled out. One that works OK when cold but fails as it builds heat will be particularly troublesome to detect.
Diesel shops have sophisticated test equipment to diagnose these kinds of issues. I would suggest that if DIY methods fail to turn up the cause, that you consult a specialist.

 

[Gittyup]

Fun to see the fuel pump dissassembled. Thanks for the photos. I never meant to imply that the fuel pump was itself electrical. Didn't mean to lead you on a wild goose chase. Just was suggesting that there are electrical parts in there that control the flow of fuel, and that they should be checked out while they are hot.

A few weeks/months back, I believe there was someone with a similar situation. As best I can recall, I think they found the problem to be a hairline crack somewhere that allowed the system to draw in air. It would only draw air after heat expansion. I hope I remember this right.

Yes, your filter/fuel bowl should be full. Have you tried bleeding the air off when it starts to misbehave, and find that performance improves? There is the little bleeder on the fuel bowl assembly to do this with.

Another shot in the dark: I think there is an electrically controlled valve that turns on/off the fuel to the injector. The relay that is controlling this could start to chatter when it gets hot and will cause fuel starvation.

I think this is also controlled by the keyswitch, which can act intermittently as well. Mine is very touchy. Barely move the key ever so slightly to the left and she dies.

 

[tlbuser]

Fuel pump is not electrical.....

Don

Oops, scratch pump insert delivery system. Relays, Fuel shutoff switch, IP, ignition switch,etc, etc. can all work intermittently due to heat load,vibration and/or corrosion.

Older diesels are simpler; fuel, air, compression and exhaust. Newer ones get complicated with EPA stuff.