I have a new (to me) Volvo L50D. 5900H. Retired state machine. The loader seems sluggish. Takes time for the engine to build RPM's. Would think nothing much of it, but I have another one that will run circles around this one. I believe it is is a fuel issue because even in neutral, climbs rpms slowly. I have changed the filters, no difference. Is there possibly a filter / diaphragm on the injection pump? Thank you.
Could be a plugged up fuel line, filters, air filter, turbo, etc. have you blown beck through the fuel lines?
I only thing I did not do is blow back the fuel lines, will do next. Do you know if there is a filter diaphragm in the injector pump?
I don’t know. Maybe the pump guy will show up and then we’ll both know
That would be great. Thank you!
If it has an inline pump -Blocked banjo bolts, dirt in or broken lift pump valves or spring, primer or glass bowel drawing air or back pressure valve broken. When you prime it you should get steady resistance and a squeeking sound after the first few pumps.
OK, I checked and cleaned banjos, checked pressures / leaks, all good. I was reading the owners manual and there is a button/function #5 ENGINE RETARDING. When I drive the loader, there is no change when I push this button. Could this be the sluggishness? I have never had a loader with this function. Is it possible that at some point the previous owner "unplugged" the non-retarding function kind of like on the older loaders people would weld a small plate over "hi" gear to keep their guys from going too fast? Has anyone seen or used this function?
That function just fixes pump displacement, it won't affect free idle. Check your fuel lines off the pump, should be one that goes clear around back to what looks like a solenoid on the intake manifold. Make sure that is not slobbering fuel inside your intake. That is a cold start assist and a big source of trouble. Having said that, let's look at your fuel source, from the tank should be soft rubber/cloth fuel hose to a glass bowl sediment strainer. Make sure those gaskets are in good order. Number one source for air intrusion. The center screw has a washer with an o-ring under it, make sure that is good as well. From there, it's off to the lift pump, on the lift pump may be a piston plunger pump for priming or a primer lever. Make sure the piston is not slobbering fuel all over when you work it, make sure to screw the plunger down firmly when done. From there it's one or 2 dinky little spin-on filters, then back to the injection pump. Check delivery pressure to the injection pump, should have between 15 & 30 psi or 1-2 bar. As an afterthought, check your air cleaners and pre-cleaner. See if any insects or vermin have built homes, choking off your air flow. Then check and verify your turbo is not broken. Good luck
Fixed. Bad linkage below foot pedal. Idle should be 800 rpm and full @ 2350 rpm. Linkage issue was OK on the low @800 but only allowed 1800 high. Thank you all!