Bobcat 863 F series will not throttle up

[MikeeDaGuy]

Hey All,
Brand new to this forum, more of a fisherman than a mechanic i guess. My Neighbor loaned me an old Bobcat 863, Her Man, my friend was killed recently and bla bla bla, I have this piece of equiptment that I am positive has not been maintained correctly, I was using it with no problem for 2-3 hours a day with small issues, like when i went to pick it up, Leaking 3/16" fuel line, Return lines? anyways easy fix and it worked great.
Yesterday I was using the machine and it bogged down, considerably, I don't run it full throttle, I didn't see the need. I parked it and looked, a line was off, I repaired it and well The machine will not throttle up at all.

I changed the in-line fuel filter, I see the secondary filter with the water trap has been bypassed and some other technological genius fixes to make the machine work. . . (no drainage on the filter installed on the filter installed) that was bypassed)

Ok bla bla bla The thing will not throttle up, it runs at an Idle, the fuel is flowing though I do not know the actual pressure. as soon as I figure out the exact parts to order (Filters) I will do so and reconnect the idle fuel filter. . . I think I need part numbers, everything look at says it doesn't work for this Model number, including anything I asked Bobcat

OK any Ideas?

thanks for reading. . .

oh the serial Number is 514431135

I only posted a new thread in case of updated information. . . thanks again

 

[brdgbldr]

This could be a lot of things.

First I would check all of the throttle linkage. Make sure everything is still connected and working.

Check the primer ball. If it has collapsed your inlet screen in the tank is probably clogged.

For part numbers, here is the Bobcat parts catalog:

Bobcat Parts Catalog - Find Diagrams for Your Equipment - Bobcat Company

Locate all parts and component information about your Bobcat equipment with detailed visual diagrams and illustrations with parts numbers and add to your list.

www.bobcatpartsonline.com

Just enter the serial number and then you can do searches by name for the parts you need or just look through the schematics.

Some items from Bobcat can be very expensive but most are fairly reasonable and you know you're getting the right part. Free shipping on orders over $99 and they are pretty quick with shipping. Otherwise you can normally put the Bobcat part number in a search engine and find aftermarket parts.

 

[MikeeDaGuy]

This could be a lot of things.

First I would check all of the throttle linkage. Make sure everything is still connected and working.

Check the primer ball. If it has collapsed your inlet screen in the tank is probably clogged.

For part numbers, here is the Bobcat parts catalog:

Bobcat Parts Catalog - Find Diagrams for Your Equipment - Bobcat Company

Locate all parts and component information about your Bobcat equipment with detailed visual diagrams and illustrations with parts numbers and add to your list.

www.bobcatpartsonline.com

Just enter the serial number and then you can do searches by name for the parts you need or just look through the schematics.

Some items from Bobcat can be very expensive but most are fairly reasonable and you know you're getting the right part. Free shipping on orders over $99 and they are pretty quick with shipping. Otherwise you can normally put the Bobcat part number in a search engine and find aftermarket parts.

Hello and good morning,
Thanks for your reply, the throttle linkage is fine, everything working properly, I can move it manually from the engine compartment, it just does nothing more than Idle.
The primer ball is working just fine, I did chance the inline filter and used it, my only concern was it was puling back fuel it pushed out, like there is no flap or anything to stop the fuel from doing that, I was thinking of adding an inline one way valve. The fuel seems to be flowing fine.

Thank you for the link, I don't know why I couldn't find that on line, its perfect, I entered the serial number and everything came right up

I was thinking of changing the fuel pump though it seems to be operation fine. I have a good friend that worked for bobcat for 18 months and he seemed to think there was air in the lines, I opened each injector for a short time to bleed any air, the RPM's actually increased a bit while doing this to each cylinder. not change to the throttle issue after completing each cylinder.

I will install a new fuel filter to have the system set up as it is meant to be, perhaps a backflow valve and go from there. . . .

again thank you for taking time to help me out and for the information. . .
Mike

 

[brdgbldr]

There should be a screen on the end of the fuel pickup tube that has a little ball check in it. Part Number 6650239

The fuel pickup tubes have a habit of cracking and or breaking off in the fuel tank. I don't think this would cause a throttle issue but it could put air in the fuel lines.

 

[MikeeDaGuy]

There should be a screen on the end of the fuel pickup tube that has a little ball check in it. Part Number 6650239

The fuel pickup tubes have a habit of cracking and or breaking off in the fuel tank. I don't think this would cause a throttle issue but it could put air in the fuel lines.

I was just looing at the entire fuel system and noticed it had a filter in the tank, my Mechanic friend told me yesterday about this filter, he works on all the equipment for the crane company I work form very smart man. . . I asked if all this fuel pressure could cause the throttle to do this, he said it could but my thoughts are it would just bog down and stall for lack of fuel. I don't know process of elimination, I knew when I borrowed this thing it was going to need some love. . .

thanks again for the input, it really helps immensely

Mike

 

[MikeeDaGuy]

Well a little update. . . I purchased a new filter package for this unit, changed what was necassary to reconnect the fuel system properly, changed the air filter. i will get to the rest later. I have no fuel problems, i am sure there is very little or no air in the fuel sysyem. It looks like someone at sometime reconfigured the intake for the fuel system it doesn't look like any schematic I have seen hahaha.
Well as a result I have no change in this thing throttling up, its at the lowest idle possible. It starts up and runs fine. I have looked and searched through the Bobcat parts catalog and searched the manual that I bought and I cannot find what is behind a plate with 3 bolts inside the cover for the timing belt, I have not removed the plate because I don't know whats in there, I have had old fishing reels fly apart and had to find someone smarter than me to fix it hahaha. Anyways I am thinking whatever is behind that plate that caused the engine to rev up when the throttle cable is moved has a problem. Maybe something broke or fell apart. . . the linkage is absolutely fine and works properly

any ideas or can someone point me in the direction of whats inside that plate?

Thanks for reading

 

[foton]

i believe that machine has a deutz diesel, so I am gonna say check the governor and fuel plate on the injector pump , something is not hooked up or frozen and not allowing fuel to ramp up. not really know much on deutz. I think these are oil cooled.

 

[MikeeDaGuy]

i believe that machine has a deutz diesel, so I am gonna say check the governor and fuel plate on the injector pump , something is not hooked up or frozen and not allowing fuel to ramp up. not really know much on deutz. I think these are oil cooled.

Hello and thank you for your reply, you are correct It is a Deutz diesel, each cylinder has a high pressure pump to each injector though one tube seems to have been repaired at some point all the pumps are working and pushing fuel. It is an oil cooled machie and it says turbo in all the specs but I do not see a turbo, it may be behind where I can't see and once the cab is raised it exposes mostlyall the hydraulics.
From what I have now located the centrifugal governor is located in what is called the "Front Cover" I am praying the problem is not inside this area, its seems like a partial overhaul of that cover, reinstlling the timing belt, possible engine removal to preform the work. . . . like I said, it runs fine, fuel is flowing, filters have been changed. . . it just will not throttle up.
I even drove it up the hill to the house because reading things and wanting to have a look became a chore. . . .
I think I need a good mechanic or someone with knowlege of this model of machine.

Thanks for reading and any responses. . . its much appreciated

 

[foton]

if it is a turbo engine with no turbo you have found the problem

 

[MikeeDaGuy]

if it is a turbo engine with no turbo you have found the problem

I just have not located the turbo if it has one, like I have stated it's a borrowed piece of equipment.

The motor idles perfectly, if you seen the hill I drove it up on idle with no bogging, it runs fine, I just cannot increase throttle.

Though new to working on this thing not on motors or even the odd diesel it just has me stumped

 

[173rdABNVN]

turbo is behind the engine. can be seen with cab lifted

 

[MikeeDaGuy]

the think ran perfectly for 2-4 hours a day for 4 days. . . a fuel hose fell of on the return, they are old, i fixed the hose and no throttle. . . I will say there was a lot of diesel fuel on the electical harness, the couple of sensors and the motor. . . . the throttle in manual and works just fine. . . . I don't see how a fuse can make this happen but they all appear good. at least the ones in the engine compartment. . .

I do appreciate all of you reading. I have no doubts if someone new the miracle fix I would know by now

 

[brdgbldr]

the think ran perfectly for 2-4 hours a day for 4 days. . . a fuel hose fell of on the return, they are old, i fixed the hose and no throttle. . . I will say there was a lot of diesel fuel on the electical harness, the couple of sensors and the motor. . . . the throttle in manual and works just fine. . . . I don't see how a fuse can make this happen but they all appear good. at least the ones in the engine compartment. . .

I do appreciate all of you reading. I have no doubts if someone new the miracle fix I would know by now

I am not overly familiar with the 863, but here are some other ideas.

Is the machine throwing any codes or alarms? Press and hold the light button and any codes should come up or "NONE" should be displayed.

It sounds like your machine may be stuck in "LIMP MODE".

You said that fuel was spilt on an electrical harness. You need to check and clean any of the connection points on the harness that got wet. Fuel can migrate in the harness and get into the connectors causing shorts. I use WD-40 Specialist Contact Cleaner Spray. Even if you can't see any moisture in the connections, clean them. The fuel can be shorting the pins in the connectors right at the base where you can not see.

It also wouldn't hurt to clean and tighten all ground points and the battery connections.

 

[MikeeDaGuy]

I am not overly familiar with the 863, but here are some other ideas.

Is the machine throwing any codes or alarms? Press and hold the light button and any codes should come up or "NONE" should be displayed.

It sounds like your machine may be stuck in "LIMP MODE".

You said that fuel was spilt on an electrical harness. You need to check and clean any of the connection points on the harness that got wet. Fuel can migrate in the harness and get into the connectors causing shorts. I use WD-40 Specialist Contact Cleaner Spray. Even if you can't see any moisture in the connections, clean them. The fuel can be shorting the pins in the connectors right at the base where you can not see.

It also wouldn't hurt to clean and tighten all ground points and the battery connections.

Good morning and thank you for the input! The two panels consist of one with 3 guages and an auxiliary hydraulic button on the right, on the left side is a key switch, the glow plug switch, a light switch, another button to engage the hydraulics to operate, (Not sure if this has been changed from its original use) my point is there is no digital readout for codes on this machine. I will have to look at the manual for error codes. Where to read them and any meaning.

I will get some contact cleaner and do as suggested, I know it can't hurt, this thing has dirt everywhere and could use a good pressure washing. Though the motor itself is fairly clean except for the diesel saturation.

Anything that is suggested that keeps me from having to remove the motor to get inside where the centrifugal governor is and see if something fell off and then find a genius with the tools to reinstall the timing belt will be fantastic. I don't think I want to tackle that just yet!

I will pull the wire wrap off and clean all the wires and contact points look for damage. Clean all the sensors and connections. "Limp Mode" sounds electrical, uggg trouble shooting is a challenge!!

Thank you for the reply

Mike

I really need to proof read my replies!! I am the typo king