2007 CAT 301.6 Mini Excavator Engine or fuel pump ????? Help please

[wulsg@elitetool]

Afternoon All,

Newbie to the site And needing some help !! Please
I have a cat mini with a L3E mitsubishi engine , The problem i have is you start machine she will start no problem you will start digging all good no bother then all of a sudden she will loose power , Engine will start to die down to an idle while the throttle is sitting at full power , some days she will work with no problems then next day loosing engine revs go down to idle ,

We have taken head off and reground values, cleaned pistons , checked cylinder bores everything looks ok but she is still loosing engine revs ,

Do you think it's the fuel pump ?????
I was thinking if it was the fuel pump then i would not start and run what is getting me is that it runs fine sometimes but then other times engine has a mind of its own

Please help before i take a sledge hammer to a l3e engine !!!!!!!!!!!!

[Muz]

Hi & Welcome to the forum .. theres a fair bit of reading on here for that engine, as its also fitted to volvo EC15's amongst others .

I take it youv'e got a good enough fuel supply? .. it should be force fed by a little electric circulating pump, and the fuel should be jumping out of the feed hose when you take it off the injection pump with just the ignition on .

[ianoz]

Is there a Filter in the Banyo fittings . Theseclog up and won't let fuel though .
Or a Plastic fuel tank , Had A Massey Backhoe have Plastic drill shavings block the tap on the tank .

[Muz]

Is there a Filter in the Banyo fittings . Theseclog up and won't let fuel though .
Or a Plastic fuel tank , Had A Massey Backhoe have Plastic drill shavings block the tap on the tank .

Yes Ive had my fare share of those too .. more commonly it was loose paint flakes from the inside of old 45 gallon drums blocking the banjo connector. The best (i say best ) was an outlet pipe on a metal fuel tank, where the weld had burst through the pipe wall thereby closing the outlet diameter by about 80% .. that took some finding , but to the OP .. its a common misconception that a dribble of fuel going into the pump is sufficient, but it isn't , it needs a good healthy flow into it. Anyway it might seem obvious, and you've already checked it ? .. let us know ?

[Mick-the-fitter]

Yes Ive had my fare share of those too .. more commonly it was loose paint flakes from the inside of old 45 gallon drums blocking the banjo connector. The best (i say best ) was an outlet pipe on a metal fuel tank, where the weld had burst through the pipe wall thereby closing the outlet diameter by about 80% .. that took some finding , but to the OP .. its a common misconception that a dribble of fuel going into the pump is sufficient, but it isn't , it needs a good healthy flow into it. Anyway it might seem obvious, and you've already checked it ? .. let us know ?

The little mitsi engines are a bit temperamental when it comes to fuel supply, does it have a hand pump device fitted in the fuel to help bleeding? If so, it doesn't need this with the electric pump, and they tend to fail internally blocking flow from the tank supply. On the right track with fuel though!

Mick

[wulsg@elitetool]

Hi & Welcome to the forum .. theres a fair bit of reading on here for that engine, as its also fitted to volvo EC15's amongst others .

I take it youv'e got a good enough fuel supply? .. it should be force fed by a little electric circulating pump, and the fuel should be jumping out of the feed hose when you take it off the injection pump with just the ignition on .

Thanks From the forum Newbie,

This engine is giving me nightmares in my sleep

Read all the thread's and we have tried everything that you all have advised to try !!!!!!
Got injectors & fuel pump checked , Cleaned out fuel tank cleaned out all pipes from tank to pump & checked banjo fitting its clear,

My next question is with the electric cirulating pump , When you turn the key the circulating pump only stays on for about 5 seconds then turns off , If you disconnect the pump and connect to a 12v supply the pump stays on !!!!!!! Is this normal for this to turn itself off after 5 seconds ?? We even changed over the relays to see if the relay was faulty and turning the pump off still the same

do they have a service reset on them as we found a jack plug under the seat ??? Incase its puts the machine into limp mode causing the engine to labour ?????

Please Please help i want to dream about other things not a nightmare L3E engine

[wulsg@elitetool]

The little mitsi engines are a bit temperamental when it comes to fuel supply, does it have a hand pump device fitted in the fuel to help bleeding? If so, it doesn't need this with the electric pump, and they tend to fail internally blocking flow from the tank supply. On the right track with fuel though!

Mick

Thanks Mick

No hand Pump, All pipes and banjo fitting clear , Please read updated post

thanks wullie

[wulsg@elitetool]

Quick update :
We think we have found the problem
One of the wires to the small fuel pump had broken , It was running intermittent ,
Because the fuel was not getting pumped continiously the engine was loosing power then stopping,
New pump ordered hopfully this resolves our problem,
Keep you updated !!!!

Thanks again for your help
Wullie

[Muz]

Quick update :
We think we have found the problem
One of the wires to the small fuel pump had broken , It was running intermittent ,
Because the fuel was not getting pumped continiously the engine was loosing power then stopping,
New pump ordered hopfully this resolves our problem,
Keep you updated !!!!

Thanks again for your help
Wullie

Heres hoping ..some do run on timers, some dont, also, some look and sound if they are running, but the flutter valves inside them fail, and even if they are running, they dont pump anything ... watch out for that one .. failing that my next suggestion would be that its drawing air somewhere

[Mick-the-fitter]

Heres hoping ..some do run on timers, some dont, also, some look and sound if they are running, but the flutter valves inside them fail, and even if they are running, they dont pump anything ... watch out for that one .. failing that my next suggestion would be that its drawing air somewhere

Well in the process of finding the broken wire, it sounds like the fuel system won't need touching for a while, well done mick

[wulsg@elitetool]

Pardon the pun !!! But she is purring like a cat again
Changed to fuel solenoid pump and she was still doing the same thing
The only other thing was to try and take out fuel tank, So we too the seat out of the digger,
Found a black cap with two pipes and a terminal connected to it, took them off unscrewed the cap its the fuel float , fuel over-flow their was a filter at the bottom of this which was totally blocked apart from a small area that was clear caused by us blowing compressed air through fuel pipes , Filter cleaned, Tank drained , Tank Cleaned ,

Put her back together and we can finally say she is purring like a cat again

Nightmares are finished now back to sweeter dreams, She fought us all the way

But we won this battle

Thanks Again for All The Advise]

Wullie from Elite

[Muz]

Pardon the pun !!! But she is purring like a cat again
Changed to fuel solenoid pump and she was still doing the same thing
The only other thing was to try and take out fuel tank, So we too the seat out of the digger,
Found a black cap with two pipes and a terminal connected to it, took them off unscrewed the cap its the fuel float , fuel over-flow their was a filter at the bottom of this which was totally blocked apart from a small area that was clear caused by us blowing compressed air through fuel pipes , Filter cleaned, Tank drained , Tank Cleaned ,

Put her back together and we can finally say she is purring like a cat again

Nightmares are finished now back to sweeter dreams, She fought us all the way

But we won this battle

Thanks Again for All The Advise]

Wullie from Elite

So a gauze in the tank ? .. I thought folks stopped doing that years ago ? .. Ah well .. its good to get to the bottom of it ... now thats another wee pun

[wulsg@elitetool]

So a gauze in the tank ? .. I thought folks stopped doing that years ago ? .. Ah well .. its good to get to the bottom of it ... now thats another wee pun

Yes right at the bottom
had my first supermodel dream last night First in a while

Thanks again
Wullie