7840 power troubles

[mayz92]

My new holland 7840 is starting to lose power at even the slightest ask of it. It is fine when at a constant rev like whilst raking, but when wrapping or using the loader it dies as you start to use it then picks back up. Also when pulling away whilst loaded struggles as if it's going to stall but will suddenly pick back up once you've pulled away.
Have changed fuel filter and cleaned bowl out, thoughts?

 

[Fordjdnashmassey]

Have you cleaned the 90degree tap at the bowl? Quite often dirt gets stuck here. Also take the pipe off the filter head that comes from the tank and blow it back to make sure it's clear

 

[Timbo]

Have you cleaned the 90degree tap at the bowl? Quite often dirt gets stuck here. Also take the pipe off the filter head that comes from the tank and blow it back to make sure it's clear

^^^ what he said.

Also have you cleaned the water separator ever ?

 

[mayz92]

Water separator being the glass bowl?

^^^ what he said.

Also have you cleaned the water separator ever ?

 

[bobk]

Blow the pipe from the bowl to the tank back , these rubber pipes can get pin holes in them , I replaced mine

 

[Timbo]

Water separator being the glass bowl?

Yes

 

[mayz92]

Yes

Yeah cleaned out when fuel filter changed. Will try the pipes suggested

 

[Timbo]

Yeah cleaned out when fuel filter changed. Will try the pipes suggested

Crap stuck in the elbow is very common, as is the primer diaphragm splitting when it's used after a filter change

 

[fermerboy]

Could be the pipe going back to the tank, most have been replaced now, a small pin hole letting her suck in a bit of air, that or as said the hand primer are often the culprits.
The 90 deg elbow is the first go to though.

 

[mayz92]

So have cleared 90 degree tap nothing really there. , blown pipe back into tank. Is it worth replacing this? And the primer?
Or is it possible something wrong with the pump? When given quick revs stationary sounds like it's choking as it comes back to normal revs for a brief second.

 

[Timbo]

So have cleared 90 degree tap nothing really there. , blown pipe back into tank. Is it worth replacing this? And the primer?
Or is it possible something wrong with the pump? When given quick revs stationary sounds like it's choking as it comes back to normal revs for a brief second.

Fill the fuel tank to the brim ( Inc top tank ) then remove the feed line at the injector pump, or the outlet at the filter head. Have you got a nice steady flow of fuel ?

 

[mayz92]

Yes once I'd pumped the primer a couple times and got the flow going was really running out the pipe of the injector pump.

 

[Timbo]

Yes once I'd pumped the primer a couple times and got the flow going was really running out the pipe of the injector pump.

If it's free flowing nicely out of the filter, i would double check for air bubbles using a length of clear pipe in place of the steel line.

If that is ok, get the injector pump off for a rebuild.

 

[mayz92]

If it's free flowing nicely out of the filter, i would double check for air bubbles using a length of clear pipe in place of the steel line.

If that is ok, get the injector pump off for a rebuild.

The old girl is just touching 12k hours

 

[Timbo]

The old girl is just touching 12k hours

Injectors as well then !

 

[bobk]

The old girl is just touching 12k hours

Diesel should pee out of the injectors , my 7840 is a bitch to bleed up

 

[agrimax]

Did you check out the small filter in the end of the injector pump? Sits around the delivery valve in the fitting that the inlet fuel pipe screws into on the pump.