863 power loss

ladderman1 · Jul 17, 2011

Hi everyone,
I am having an issue with my 99, 863 skidsteer. the machine starts great and idles fine. When I turn up the idle on the machine it runs good for a few seconds and then starts to idle down and almost stall. If i turn the idle back down it's good again until i crank the idle up again. I am thinking a fuel issue. Has anyone else had this issue.

hydro2 · Jul 17, 2011

It could be a fuel filter clogged with either water or dirt. The smallest amount of either can cause the symptoms you described.

ladderman1 · Jul 17, 2011

Yeah thats what i was thinking as well. I will pick up a filter and change that out. hopefully that will fix the problem. Thanks

hydro2 · Jul 17, 2011

You are welcome. Keep us posted on your progress. I have a duramax and it runs horrible with a dirty filter. Filters arw cheap and a good place to start.

hydro2 · Jul 17, 2011

Don't forget to fill your filter with diesel before you put it on.

ladderman1 · Jul 18, 2011

will do thanks

ladderman1 · Jul 21, 2011

Ok well I replaced the filter today ran the skidsteer and had the same problem I would idle up and the unit would drop to an idle then go back up again. It's seems to surge and drop then surge again so I'm kind of stumped
I'm going to change the fuel bulb tomorrow maybe it's collapsing.

dex3361 · Jul 21, 2011

Check and see if your fuel tank vent is plugged by loosening the cap when it starts. Check inside your fuel tank for debris that can restrict the fuel flow. Take the line loose to the fuel filter and see if it ha good fuel flow. Sometimes the fuel line can get plugged up or the hose can break down and cause the fuel to be restricted. :thumbsup:

SSdoxie · Jul 21, 2011

When the RPM starts to drop off, squeeze the primer bulb to see if RPM comes back up. If it does, the lift pump is likely the problem. If RPM doesn't recover when squeezing the bulb, check fuel supply line back to tank and possibly pickup tube in the tank. The fuel line comes from the tank and runs under the engine. If the rubber engine mounts become soft and compress it can lower the engine down to squeeze the fuel supply line between the fuel tank and the oil pan. Debris build up in this area can also put enough pressure on fuel line to compress it and restric flow. Something in the tank could be partially blocking fuel pickup tube.

Just a few thoughts and things I have run into over the years.

hydro2 · Jul 22, 2011

Wow I was hoping it was the filter.

ladderman1 · Jul 22, 2011

Well the bulb is not collapsing. I sweezed it when the problem occured and made no difference. So it must be plugged somewhere. how do you get at the tank? I lifted the cab, hydraulic tank is in front. Is the fuel tank under the engine? Sorry if I sound new to this, as I am.

SSdoxie · Jul 22, 2011

ladderman1 said:
Well the bulb is not collapsing. I sweezed it when the problem occured and made no difference. So it must be plugged somewhere. how do you get at the tank? I lifted the cab, hydraulic tank is in front. Is the fuel tank under the engine? Sorry if I sound new to this, as I am.

The fuel tank is under the engine and has a rasied portion between the engine and hydrostatic pump package. On right hand side of engine follow your fuel fill tube down to wear it goes into the tank then slighlty behind that and towards center of the tank are the fuel pick up tube and fuel retrun going into top of the tank. Both lines go into the tank through a barbed fitting pushed though a rubber grommet, pulling up and twisting at same time will bring th grommet and fitting out of the tank. Will most likely need a new grommet when you put it back in.

Before taking the fuel lines out of the tank, check for restricted line under the engine. Push & Pull on the fuel line to see if it moves freely. You can also remove the 2 rear engine mount bolts and use a pry bar to lift engine slightly and block it up. Start engine and see if it runs better, if so fix fuel line problem between tank and lift pump.

ladderman1 · Jul 23, 2011

Well I finaly got the pick up elbow and grommet out of the tank. there was no pick up tube on the elbow so I think I found the problem. I have to wait till mondat to pick up a new tube so i will keep you all posted. Thanks everyone for your help.

franklinute · Jul 23, 2011

I have an 843 Bobcat and have used a coathanger wire to retrieve the fuel pickup line in my tank. There should be some sort of screen on the end of the pickup hose. I have seen these hoses get old and soft enough to collapse. Anything over 12-15 years probably time for new fuel hoses.

SSdoxie · Jul 23, 2011

ladderman1 said:
Well I finaly got the pick up elbow and grommet out of the tank. there was no pick up tube on the elbow so I think I found the problem. I have to wait till mondat to pick up a new tube so i will keep you all posted. Thanks everyone for your help.

Did you pull both fuel lines and grommets out? There are 2 of them. The fuel return line does not have a pick up tube by design. Without a pickup tube on supply line, engine would not run at all unless completely full tank.

ladderman1 · Jul 27, 2011

I'm up and running. The one line that I pulled still had the clip for the pickup tube on it. Seems to be good now. Thanks for everyone's help. This forum is a great tool

LWG · Jul 30, 2011

I have a similar problem. There is a power loss, and the primer bulb has collapsed. Can I blow it out with compressed air? I thought it was tough to get the fuel filler cap off. Where is the vent for the fuel?

SSdoxie · Jul 30, 2011

The fuel cap is vented, but if the vent cap is plugged it will create vaccuum in the tank after running awhile. Try a new fuel cap first.

ladderman1 · Jul 30, 2011

if you have a full tank of fuel can you run the skidsteer for about twenty mins before it loses power?
The breath tube runs to the fuel fill top and breaths through the fuel cap. replace the bulb first it may be collpaing because its weak. then replace the fuel cap
then if the machine runs like i said you might have to get into the pickup tube on the top of the tank and replace it. that job is a bit of work that why i suggested the vent and bulb first.

LWG · Jul 30, 2011

I saw another thread where to replace the pickup they cut through the rubber filler tube, inserted a short length of steel tubing that that a flattened section, and ran a replacement pickup through fittings on the inside and outside of the steel tube. Seems like a clever solution. I also saw that the fuel lines can get pinched under the engine. I got some things to look at tomorrow.

The machine ran a few hours today with a half a tank before it lost power.

I was thinking that I could reverse the bulb and use it to squeeze fuel back into the tank, and through the filler tube.