# Low rpm



## Mark68 (Jun 21, 2019)

I have a 2012 mahindra 4025 tractor. I recently replaced the fuel lines and filter. It ran fine for a couple of hours and then the engine died. I bled the injectors and got it running again. However it will not run over 1700 rpm with or without a load. I installed another filter changed all of the crush washers on the fuel line banjo fittings checked the screen in the fuel tank and nothing has helped. I'm confident it's not a problem with air in the fuel system. Does anyone have any thoughts?


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## thepumpguysc (Jan 25, 2015)

Mark.. usually people don't change their filter until theres a problem..
Pull the line closest to the fuel tank & let it flow.. check it for slowing down.. floaters in the tank.


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## Mark68 (Jun 21, 2019)

thepumpguysc said:


> Mark.. usually people don't change their filter until theres a problem..
> Pull the line closest to the fuel tank & let it flow.. check it for slowing down.. floaters in the tank.


I have done that a couple times now. I had to drain the tank when I changed the hose. That looks fine.


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## thepumpguysc (Jan 25, 2015)

Does this engine have a mechanical inj. pump or is it a common rail system.??
I would make sure the throttle was getting full travel{mech. IP} from stop screw to stop screw.
& that it was getting enough fuel to run..{supply pump}


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## Mark68 (Jun 21, 2019)

I'm no diesel genius so I will try to explain what I have. Stop to stop has been verified. I have four independent fuel lines that come from the pump to the individual injectors. All 4 injectors are tied in with a single return line to the tank. I do not know how to determine if I'm getting enough fuel from the pump. All help is appreciated.


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## Mahindra One (Aug 4, 2006)

Mark68 said:


> I have a 2012 mahindra 4025 tractor. I recently replaced the fuel lines and filter. It ran fine for a couple of hours and then the engine died. I bled the injectors and got it running again. However it will not run over 1700 rpm with or without a load. I installed another filter changed all of the crush washers on the fuel line banjo fittings checked the screen in the fuel tank and nothing has helped. I'm confident it's not a problem with air in the fuel system. Does anyone have any thoughts?


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## Mahindra One (Aug 4, 2006)

I have that exact tractor, including the year. With only 115 hours, and running fine I decided it needed a new filter. I won't go into all the costly and time consuming details but although I'm pretty sure I have rpm, I broke the first banjo bolt and live in fear of breaking the second one, ergo, it leaks some and I have to pump it for each start. Live and learn! Good luck.


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## Mark68 (Jun 21, 2019)

Mahindra One said:


> I have that exact tractor, including the year. With only 115 hours, and running fine I decided it needed a new filter. I won't go into all the costly and time consuming details but although I'm pretty sure I have rpm, I broke the first banjo bolt and live in fear of breaking the second one, ergo, it leaks some and I have to pump it for each start. Live and learn! Good luck.


Thanks I've broken one of those as well and stripped out the bleeder hole in the hand pump. I have all of that replaced with no leaks and I'm confident that I have no air leaks at this point. All I can think at this point is something's wrong with the injector pump


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## bmaverick (Feb 20, 2014)

First, not all filters are the same. Wow, that's a loaded answer. LOL 

What I mean is, sure the size is the same, the threads to screw on are the same and the seal ring is the same. BUT, the question is, how much FLOW can the filter media manage??? IF the new filter requires more flow pressure vs the old one removed, chances are the rpms can't get past a low idle. 

Generally, I just use a standard WIX or Puralator filter.


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## Mark68 (Jun 21, 2019)

bmaverick said:


> First, not all filters are the same. Wow, that's a loaded answer. LOL
> 
> What I mean is, sure the size is the same, the threads to screw on are the same and the seal ring is the same. BUT, the question is, how much FLOW can the filter media manage??? IF the new filter requires more flow pressure vs the old one removed, chances are the rpms can't get past a low idle.
> 
> Generally, I just use a standard WIX or Puralator filter.


I bought the filters from mahindra. It's the same Bosch filter as the original. I've thought about bypassing the filter but not sure how to bleed the air out of the system when I do it


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## Mark68 (Jun 21, 2019)

I have finally found the problem. When I replaced the fuel lines that tend to break down and leak every 2 or 3 years I ended up swapping the banjo fitting bolt from the inlet side of the pump with the outlet side which is the return line to the tank. The return line banjo bolt is a restricted fitting. So i had restricted fuel going into the pump and unrestricted fuel going back to the tank. I swapped the bolts and all is good now Just fyi. I also built a new tree trimming attachment.


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## pogobill (Jan 31, 2012)

Thanks for the update Mark68. I guess you are relieved that you have is sorted. 
That tree trimmer is going to be handy, just don't get under any of the branches or limbs you are going to trim. I made a similar rig a few years back as a temporary one off to get at a broken limb that was to high up to access with a ladder. I used a length of sash cord to operate the throttle.


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