Hi all good people!!! I have a case of 1999 Leibherr 914 litronic with Deutz 924 T engine, Injection pump is Bosch VE. Excavator is a bit slow to operate. It can not raise bucket above average truck height in time it makes 180 degree turn. It always takes few seconds of cranking before it starts up, warm or cold. When on idle, if command is given, it stalls, no matter warm or cold, which I've never seen happen before on any excavators. When running on full power, if loaded fully, RPMs drop by some 600 or so. This leads me to believe that there is some sort of a problem with injection pump or injectors. I have measured turbo boost so far and I get reading of about 0,60 bar max. I have engine workshop manual but it staes that boost pressure can be 0.6 to 2.0 bar, depending on a model of an engine. So no much help there. Did anybody have similar problems like this one? What else can be checked before I take out fuel pump and injectors for further check and repair? Excavator was looked at by other workshop that measured hydraulic pressure and stated that pumps can not rech max. pressure because of a weak engine. Unfortunately no numbers were given for readings taken. Excavator was purchased recently and you can see that pump was taken off recently maybe even changed because it is not painted leibherr yellow. Also on turbo compensator cover, one screw has different head than other 3. So at some stage, somebody played with it. So if you have any pointers, please let me know!!! Many thanks!!!
For starters, does this machine have an ERC accumulator? If there is, it will be a large cylinder located between lift cylinders. Do you have issue with arm and bucket functions? How about swing and travel?
The low boost could be results of poor fuel pressure. Have you serviced your fuel filters and verified that you have no leaks (sucking air)
No erc on this machine. There is a cylinder between lift ones, but it is for two part boom that this machine has. There is no other specific issues with any movement except that it is slower than it should be and lacks on power overall. Fuel filters were serviced few months ago. So I have been told. Wasn't done by me. No paperwork trail, so can't say for sure. As far as sucking air in, I haven't noticed anything. All fuel lines are in good condition and everything is tight. Another thing I forgot to mention. This machine uses 16 litres per hour when it should be using 12.5-13 max. So something doesn't add up there as well. It might be that it's not lack of fuel but bad timing or some other adjustment. There is no blue, black ,white or amy kind of smoke from the exaust.
Will swing against swing brake stall the engine? If not, I would be more suspicious of the engine. Higher fuel consumption combined with low power would indicate a boost leak or choked air intake. You mentioned someone may have messed with the turbo , might be worth checking for loose housing, blown seal, damaged wastegate etc.
The very first tests I would do would be inline with engine testing. Does it have blowby? I don't know the engine but likely old enough to just have mechanical injection so when you whack the throttle, you should see a puff of black smoke and hear that turbo get after it. If not, start there. With high fuel consumption, I would suspect compression, injectors, timing, etc. many times the exhaust will smell like raw fuel BUT in those cases, blue smoke will show up. Pull the damn air filter out and see what it does! I fixed one doing just that. Filter got moisture on it and would not flow air. i think you need to do more to determine what boost pressures should look like. I could also suspect a worn turbo. maybe not a "leak" but worn turbines will spin up fine, but not build optimal boost, but just enough to limit black smoke. the exhaust pipe inside color will help determine this.
Got a call from the customer today. For some reason they decided to buy new fuel pump and injectors. Beats me how they came to that conclusion, but someone has got money to burn. I'll post an update once pump and injectors are up and running.
It's the typical parts changer at work! "We don't know what the problem is so lets throw parts at it until the issue resolves." Fueling issues can typically be spotted with gauges. Delivery side might show very high vacuum and a weak output side from the pump would show a drop in pressure as more fuel is requested from the engine.
Yeah it seems that they have taken that approach. We just got into diagnosing and they are changing pump and injectors even without pulling tjem out and checking. Oh well, their money.
Everything was ready for pump replacement this morning, until it was unpacked. Wrong pump, version for non turbo engines. Hand washing and blaming game started. Correct pump in about a week.
And AGAIN wrong pump sent directly from Germany. Someone is realy not knowing what they are doing Customer is steaming from his ears now
Have you confirmed that the engine has not been swapped to another model. Perhaps the pumps are right and the engine wrong?
Chasis number and engine number match. Only other option might be that this was non turbo engine, and someone added turbo. But as I was told, there is no non turbo engine for this model. All this ordering is done by the customer, so I'm just watching until correct parts arrive.
Glad to hear you're not on the hook for any of this.
Me too!!! I was strogly biased to do more investigation and diagnostics before we start throwing parts at it. But I don't call the shots in this case, so we wait for another attepmt of pump delivery.
So apparently it was concluded that this engine was tampered with, and different kind of pump was installed. Original pump doesn't have turbo compensator, but engine still has turbo (apparently this set up gives you about 10-15kW less power). So main dealer washed their hands from it straight away. Unable to help because of different pump, go figure. Old pump and injectors were taken out and sent away for repairs. Pump housing was worn and few different bits. All replaced. 2 out of 4 injectors were barely working. All 4 injectors reconditioned. Now it's a completely different machine. Starts up straight away, doesn't stall on idle, speed has improoved very much, and very steady RPM during operation. All good in the end. Just a bit of complication with the dealer and their approach to the whole situation.