Backhoe won't restart when hot. pump?

[Sebculb]

Hola everyone,

Does anyone have experience with a machine that's difficult to get running again after it's been running and is hot? It'll turn over no problem in the morning when it's cold but once it's hot I have to use the magic gas rag to restart it or wait a few hours to cool down.

My mechanic says it could be the injection pump. He also says it's expensive to rebuild so I hope it's something else. Any other ideas? 1997 JD 310D backhoe. Thanks !

Sebastian

 

[4570Man]

My dump truck has the same problem. It’s got a coolant temperature sensor and won’t engage the glow plugs when hot. The engine doesn’t like that idea. I put the glow plugs in a switch so I can flip them on whenever I want and problem solved.

 

[Sebculb]

Thanks! ...but this thing doesn't have glow plugs so that's probably not the issue. Good looking out though.

Any other theories?

 

[thepumpguysc]

Its VERY possible that the head & rotor in the pump is worn.. it quite common..
The thing that causes THAT is dirty fuel..
& yes they are expensive to rebuild "if" you have to replace a H&R.. you might be better off getting an "exchange" pump..
The only way to determine a bad H&R is, tear it down & visually inspect it or put it on a test stand & get a calibration check done..
BUT>> 80% of the fuel shops wont do a cal. check on a pump that hasn't been rebuilt.. for fear of contaminating their fluid..
There ARE other things that contribute to a no-start hot condition, other than a bad H&R..
The pump might JUST NEED a few new parts.?? {basic overhaul} The only way to tell if its the pump is to take it off & send it in..

 

[Tx Jim]

Ditto on possible worn H&R in IP. If engine turns over slower when attempting to start at operating temp due to hyd pressure build-up one can rapidly turn steering wheel back & forth to relieve hyd pressure while attempting to start engine.

 

[Sebculb]

Thanks Pump Guy, pretty much corroborated what my mechanic said exactly. I'm looking into new-previously owned pumps right now and seeing if that's a lesser hit.

TX Jim, thanks for the tip, I'll try that with the steering wheel and see if it helps. But today it was being stubborn cold in the morning and needed the magic gas rag, so it may be getting worse.

Looks like some pump maintenance or something is on the way.

Thanks everyone!

 

[PILOON]

Might not poor compression also be a factor?
When hot metals expand maybe a hot vs cold compression check is worth doing.

 

[BertZegers]

Might not poor compression also be a factor?
When hot metals expand maybe a hot vs cold compression check is worth doing.

I had a diesel car that would not start when warm. The engine had low compression, was worn out. Compression check is a good idea before spending big money.

 

[Sebculb]

Hmmm, thanks PILOON and Bert! I'll look into the compression idea. Sorry for the slow reply, don't always get notifications for new posts. That's interesting cuz I just found some aluminum shards in the bottom of my oil pan during an unrelated matter, which means I may have some piston damage...