First, thanks to all the wisdom on this forum. Many of you helped without even knowing you did. I was able to get my m-274 mule and m-998 squared away just by reading past posts and reading TM's. This 803 has me stumped though. I purchased this runner about a month ago. Once I got the unit home, I replaced fuel filters, oil & filter, flushed coolant and added fresh batteries. Unit started ran and got to temp fine. I was having an issue with it overloading when I got above 50 but resolved that issue with cleaning out S6. Now I'm experiencing something completely different. Unit starts, builds oil pressure and idles. After a short time, without load, the engine sounds like it has a miss. I believed it to be a fuel delivery issue so I have replaced the fuel pump, return lines and bled the injectors. Not sure what's going on with it now. Still doing the same thing. I installed a coupling in the return line and barely any fuel comes out when disconnected and bleeding off into a catch can. Seems as though there isn't enough fuel. Getting ready to dive into the TM's and check injectors. Headed in the right direction?
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Mep 803a Fuel Issue
- Thread starter Megalug
- Start date
- 16,777
- 24,103
- 113
- Location
- Burgkunstadt, Germany
Take a picture of your electric fuel pump and post it. Remember, if the fuel pump won't deliver to the engine, it can not run right.
- 2,145
- 3,526
- 113
- Location
- Pepperell, Massachusetts
You might want to disconnect the outlet from the fuel pump and see what the flow is like.
Did you replace the filter on the inlet to the pump? It may be clogged.
Did you replace the filter on the inlet to the pump? It may be clogged.
- 3,829
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- MA
Start with these two posts above me, and let us know. You do have a handy replacement (the aux pump) built into the machine if you want to diagnose more.
Bmxenbrett
Member
- 602
- 30
- 18
- Location
- NY
There are two fuel pumps. One primary and one aux fuel pump. What one did you change and what part number did you put in?
Do you have 24v at the fuel pump?
Do you have 24v at the fuel pump?
- 3,829
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- MA
I was going to address voltage after fuel answers. 24V devices need 24V... not 23.2, not 22.7, etc.
Even though they are new batteries, verify you are getting over 24V.
Even though they are new batteries, verify you are getting over 24V.
Thanks for all the replies gents. I will get some pics up when I get back to the machine. Had to finish a job out of town but will be back home on Thursday.
I replaced the pump with a Airtex E8131. And yes, new filter inline prior to the pump. I disconnected the outlet side of the pump and it was a pretty weak flow but flowing. Pulled the gas cap to inspect the tank, looked ok and could feel the pick up tube sucking. Bled all the lines at the injector per the TM and disconnected the return prior to going back into the tank. Again weak, but flowing. I've ordered an inline fuel pressure guage that I will pipe in when I get back.
The 24v question may reveal something. I wired a few LED's in the cabinet. Although it's a very low amp draw, it's a draw. I'll disconnect the fuse and let the bettery tender bring the batteries back up if applicable.
Ill check back in on thurs or Friday and let you guys know.
I replaced the pump with a Airtex E8131. And yes, new filter inline prior to the pump. I disconnected the outlet side of the pump and it was a pretty weak flow but flowing. Pulled the gas cap to inspect the tank, looked ok and could feel the pick up tube sucking. Bled all the lines at the injector per the TM and disconnected the return prior to going back into the tank. Again weak, but flowing. I've ordered an inline fuel pressure guage that I will pipe in when I get back.
The 24v question may reveal something. I wired a few LED's in the cabinet. Although it's a very low amp draw, it's a draw. I'll disconnect the fuse and let the bettery tender bring the batteries back up if applicable.
Ill check back in on thurs or Friday and let you guys know.
mike1976
New member
- 19
- 5
- 3
- Location
- marshall mo
Check all the fuel line connections from tank to pump they vibrate loose and will make the engine sound like it has a miss
mike1976
New member
- 19
- 5
- 3
- Location
- marshall mo
It will suck air but fuel will not leak out . I found mine by accident when i had the cover off the fuel tank looking for an electrical issue and looked at the lines while i was there and the fitting at the suction tube was almost ready to fall off
- 16,777
- 24,103
- 113
- Location
- Burgkunstadt, Germany
Loose fittings are a leak, yes.
Consistent flow from the pump is a must. The pump is only supposed to slow down when the fuel system is empty, or better said, not full. So the output PSI will stay the same.
Consistent flow from the pump is a must. The pump is only supposed to slow down when the fuel system is empty, or better said, not full. So the output PSI will stay the same.
And the winner is ........mike1976. Thank You brother.
Got home from work and decided to try the easiest first. Took the supply line off the pump and put it right into a fuel can and primed. Fuel pressure/flow great. Reprimed and bled lines and fired it up. Sounds and runs great. Loaded up to 11.5 and gene did fine. Thanks again everyone.
Got home from work and decided to try the easiest first. Took the supply line off the pump and put it right into a fuel can and primed. Fuel pressure/flow great. Reprimed and bled lines and fired it up. Sounds and runs great. Loaded up to 11.5 and gene did fine. Thanks again everyone.