6748 not starting as well

[idrivea5748]

Hi all,
I just joined this forum as need help with a 6748 not starting as well. had injectors serviced still no inprovment. ok in summer just takes longer winding over in winter.

 

[zetormatic]

i found a seized lift pump in my 3545??? i fitted a new one and it starts first time maybey you should try one

 

[paul_walpole]

Does this modle have a cold start button??
If no and the lift pump is ok, try pumping it beforfe starting it cold. If by pumping it until you hear fuel going back to the tank makes it start cold then put a non return vavle in the fuel line before the injector pump but after the filters

 

[Gareth]

yes it has cold start button and that did help at start but went back to pour starting after. so I tried pumping the lift pump and that helped so fuel must be going back down line to tank somehow. cheers for info.

 

[Renze]

The 6748 has a tank mounted in the hood, so it is gravity fed. It cant suck air unless you have some really plugged up fuel lines. You can blow them back with air, right from the filters back into the tank. A seized lift pump can also obstruct your fuel flow.

 

[ixer0]

It could be the non return valve not sealing on the return line in the banjo on the back of the pump. This causes the fuel chamber to drain back enough to cause slow starting.

 

[stinkyhinksy]

did you ever get this starting problem sorted out?
mine is slow starting now. cold start button does help but the revs are at full so i move the lever to 1000. some one told me to put 10% petrol in ? thanks

 

[ricc]

cold start button only locks in if the throttle is fully open , its supposed to start on max revs... close it down after its fired up...

 

[bigdoug]

This thread has my interest! To start my 3340 when I haven't started it for a few hours, I have to pump it until I hear fuel going back into the tank. It's been like this for a year but I've been to lazy to work on it. If I understand the notes, there could be a one-way valve that's not working correctly and allows fuel to drain back into the tank. Is that true for a 3340? Where is it located? I was going to change the hand pump but it costs $160 and looks like it's hard to remove (two hydraulic lines running right in front of it).

 

[stinkyhinksy]

thanks ricc.

it does always start after a while. maybe i am just being to fussy.

mark

 

[ixer0]

Doug

The non return valve is on the banjo bolt on the rear of the pump where the return line connects. It's more likely one of your return or leak-off pipes is perished. Have you still got the old braided type fitted as they get perished under the covering. Look for slight leaks if you clamp the return line and then pressurize the system with the hand primer.

Mike

 

[bigdoug]

Thanks Mike. I'll give it a try!