Frustrating D3G

[E189552]

I have been trying to diagnose a loss of power problem with my D3G (s/n BYR01978).
Machine will lose power & slow to a stop, slowly gain speed, rinse & repeat.
No codes showing.
Checked brake system hydraulic pressure - all good.
Parking brake switch function - good.
Both pedals function properly.
Replaced motion directional control with no effect.
Need help as to where to look next, I’m out of ideas.

 

[ih100]

Filters/oil level/correct oil/tank strainers? Not treating you like an idiot, but always worth an ask. Start with basics.

 

[d9gdon]

Take the elbow out of the fuel line between the fuel tank and the filters and see if a piece of trash is in there...it's a common problem.

Another problem is the hand priming pump on top of the fuel filter housing...it will suck air there.

 

[Mike L]

When you say “lose power” do you mean the engine loses rpms and dies down? Does the engine skip or blow smoke? Does it stall? I’m guessing that it’s a fuel or air problem. Check all the easy stuff like fuel and air filters, inspect the turbo and cac.

 

[E189552]

The engine acts like it is under a load.
It does smoke when it slows to a stop.
If anything the engine sounds like it has a stutter (I know-sounds like a female description)
I replaced fuel & air filters.
Any way to check turbo output?

 

[Mike L]

It sounds like it’s starving for fuel. I’d check that elbow like d9gdon suggested and at that point you probably need to check fuel pressure and possibly check to see if you are sucking air somewhere

 

[ih100]

I misunderstood the issue, thought you were losing drive. What type of priming pump does this have? Some of the plunger types were bad for drawing air round the plunger. I've had a brand new one fail the first time in use.

 

[E189552]

Pump is a small, self priming electric job on top of the filter.

I know the pump seems to run for maybe a minute or so when I start the machine.
Is that length of time normal?

Anyone know what the fuel pressure should be?

 

[E189552]

Latest update:
Started engine this morning, brought up to full throttle and in just of few seconds it began to stumble.
Too lazy to remove lines at the tank .
So I took my air compressor, took lines leading to tank loose & blew air back into tank.
cut one end off of frayed hose, reconnected everything - so far it has run like new.
Real test will be when it gets hot this afternoon, seems that is when it stumbled most often.

 

[Nige]

I'm glad you got to the bottom of it. It comes of not being there with the machine but when your original post spoke of Diagnostic Codes the logical conclusion was an electrical/electronic issue. It all goes to show that checking the basics first is always the best idea.
Question: Do you drain water & sediment from the fuel tank at all..? The recommendation is every 250 hours or monthly. Which brings up another question, do you have an O&M Manual for it..?

 

[E189552]

Nige I really appreciate your help. All of your information helped to diagnose what it wasn’t.
I wonder if some of the codes were because of the engine not producing sufficient current.......
I am a bit more educated than I was about what makes this machine operate.
I was convinced it was hydraulic or electrical, hindsight being 20/20, should have checked the basics first.

As far as draining the tank, tried that but the stem of the valve twisted off. Corrosion on the outside.
I did look inside the tank & it was reasonably clean. Some surface rust spots, so Plan is to keep tank as full as possible.
Yes I did get the O&M manual. I plan on getting all maintenance items up to date

ih100, MikeL, d9gdon you guys were awesome in steering me in the right direction.
One of those facepalm moments, DUH! Fix was so simple, been chasing ghost problems for a long time.

 

[Nige]

Maybe a good long-term plan might be to replace the drain valve, even if that requires the tank to come off..?
Keeping it full of fuel is a good idea but long-term it still won't stop debris accumulating.