Excavator losing power

[Shivan Dookeran]

Hey guys my 320dl serial kgf00762 is losing power intermittent when hot , changed all filters thinking it was that but same thing , I checked but no active code
Only thing is the boost pressure keeps jumping up to weird numbers .
I am attaching 2 pic with the numbers I am seeing . First one is the weird numbers when it loses power and the other when it works fine .
Question is what numbers shoukd i be seeing and which sensor I need to change if it is the boost sensor ?

 

[Nige]

Does your machine have a viscous fan clutch.?
What makes me ask is the big difference in fan speed between the two photos.

 

[Shivan Dookeran]

Yes it does ,I kinda attribute the fan speed due to the engine slowing down, engine Temps holding normal.

 

[Nige]

Yes it does ,I kinda attribute the fan speed due to the engine slowing down, engine Temps holding normal.

Why was the engine slowing down between one and the other when the speed control was in Pos 10 in both photos.?

 

[Shivan Dookeran]

That's what I'm asking , is the values from the boost sensor out of whack? I'm seeing 32747.5kpa vs 66.5kpa when it's working fine

 

[Nige]

Tried cleaning the boost sensor harness connector yet.?
You have access to ET don't you.? Any codes.?

 

[Nige]

which sensor I need to change if it is the boost sensor ?

It's called the Inlet Manifold Pressure sensor in the Parts Manual. Ref #4 on the attachment. Be careful because the one next to it (Ref #1A) is an air temperature sensor.

 

[Shivan Dookeran]

Tried cleaning the boost sensor harness connector yet.?
You have access to ET don't you.? Any codes.?

Harness is clean and no codes coming up ,I know it's a sensor acting up because when the machine is cold it works fine , the values I'm seeing from the input sensors are all fine except this one which seems to be jumping all over the place

 

[Nige]

Check your PMs.

 

[John C.]

The boost reading goes from 4750 PSI and then down to 10 PSI? Why is there a difference between boost and turbo out.

 

[Shivan Dookeran]

The boost reading goes from 4750 PSI and then down to 10 PSI? Why is there a difference between boost and turbo out.

Is it supposed to be the same?

 

[Nige]

Why is there a difference between boost and turbo out.

Atmospheric pressure sensor. Boost = turbo out pressure minus atmospheric pressure.

 

[Shivan Dookeran]

Seeing the machine is close to 15 years I think I’m gonna start seeing sensors and other stuff giving up

 

[Nige]

Seeing the machine is close to 15 years I think I’m gonna start seeing sensors and other stuff giving up

Just bear in mind that in addition to sensors the age of the machine you also have 15 year-old wiring harnesses that are just as likely to give problems caused by age-related embrittlement.
It is a recurring theme on HEF that someone starts with "I had such-and-such problem, replaced the sensor and that didn't fix it. What do I do now.?"

 

[Shivan Dookeran]

That's true and I'm very much weary of that, I may seriously consider going the cheaper way first, which is the sensor but seeing the engine harness is subject to the most heat I'll look into eventually changing it .

 

[Coaldust]

Sometimes, it pays to see what those sensor values are with Key on Engine Off. Then you can compare actual ambient values to the sensor readings. Easy way to tell if one or more are wack.

 

[Shivan Dookeran]

Changed the sensor and it's working fine so far , can anyone say what is the harness part num? I'm seeing one 296 4617 but I'm not sure if it's the right one for my machine .

 

[Nige]

I'm seeing one 296 4617 but I'm not sure if it's the right one for my machine .

296-4617 is the harness for all the engine sensors for a KGF-prefix. It is correct for your machine and services to a newer number 520-7000.