Mitsubishi L3E .. again...

[richp999]

Hi

A a year (or two?) on from my partial engine rebuild of my L3E (Volvo , 271) and its giving me issues again.

I've spent the last 2-3 days with the fuel pump out, injectors etc..

It's not been used much over the past 6 months or so but I started it probably every 2 weeks or so and ran for a little while to make sure all was ok.
Didn't have an issue starting it once.

Had to replace a hydraulic line last weekend, to do some work in garden... all went well.

Started up ok, and worked for an hour or so. Turned off, then about 15mins later tried to start and it just wouldn't go.

Had just been running fine.

I remember it has done this before, a year or so ago, but I thought that was behind me now!

So I've had the injection pump off and in bits, all tested (as much as I can) and seems ok.

Fitting it again and hooking up the injectors, outside the engine, got them all spraying ok.

Got a new battery incase it was that, put it all together and after a few turns eventually got it running.

Sounded ok, maybe even running a bit better, but again stopped it, and it wouldn't start again.

It just won't start when its got a little bit hot, or been running for a very short while.

Once its going, it seems fine; power's great etc...

Has anyone seen this before? Any ideas?

I have found once it won't start after running, if I give it a 0.5-1 second squirt of Holts Cold Start, it fires straight away and runs great. Every time.

I checked almost everything on this engine , but does anyone know:

1) The injectors are original and probably getting on a bit , but I tested them and seem not too bad. Before I replace them, is it possible for them to 'stick' when then get hot ? i.e. whilst the fuel is running through them they're fine, but when i switch it off maybe they heat up and stick ??
Don't know why spraying with the cold start would fire them into life - maybe a sudden higher fuel pressure unsticks them ??

2) The high pressure fuel pump is the other older bit that I thought might be a bit tired - could the performance of this drop when it heats up ? (Maybe ok when running, but when hot and trying to start doesnt give enough pressure ?)

3) Fuel - This might have coincided with a re-fuel of new/different fuel delivery - could this cause hard starting ?

Thanks in advance for any ideas...

[Wazza]

I had a tractor that had a sticky slide plate(think that's what it was called) in the injectors and that had the same symptoms, would run fine but if you stopped it it wouldn't allow fuel to flow again and as a result it wouldn't start.
Have you tried adding an injector lubricant to the fuel ? ..

[richp999]

No, I'll get some today.
Was going to change the fuel out first, i see if I can order some injector lubricant..

I managed to start it a couple of times when it's warm /hot last night, but it took a fair amount of starter running and glow plugs on to get it to fire.
Sounds like it wants to go for a while, as if one cylinder is going, then eventually runs.. Not all the time though.

I'm considering 3 new injectors ; just wondered if anyone had seen this issue. I wasn't sure if it ran that meant the injectors were fine ; I don't know if they could run fine one minute but then be difficult to start the next.

Anyway it seems to have developed since kind of knocking noise now 🙄 so going to investigate that today.

That new l3e on ebay looks more and more tempting 🤔

[Muz]

Those pumps are timed using shims under the pum body where it bolts to the engine block ie they can be raised or lowered a few thou that alters the timing .. im wondering if youve got that altered a bit so it wont run hot properly ?

[richp999]

Those pumps are timed using shims under the pump body where it bolts to the engine block ie they can be raised or lowered a few thou that alters the timing .. im wondering if youve got that altered a bit so it wont run hot properly ?

Hi Muz..

Think the timing is ok - I tried to rule that out today by taking the shim out, and running it. Also by 'adding' a shim (or substitute for) , just to see. In both cases, it started, but ran roughly. When I went back to the original shim it ran fine, so I reckon that one's ruled out.

When I had the pump out I cleaned all the plungers etc, replaced 3 washers below the delivery valves and that seemed to hold the pressure in the fuel line up to at least 2500psi.

The pump seems to be operating pretty well now, so i'm a bit happier with that.

I'm gonna hope its something to do with the fuel - i'm going to drain it and buy some new diesel, and try an additive in it ; hopefully to lubricate the pump/injectors a bit.

When I tried it today, it started straight off from cold ; and I did manage to start it 5 or 6 times afterwards, and it went every time, albeit sometimes takes a few seconds and some extra glow plug..

I've got another issue with the center cylinder knocking now, so I'm trying to solve that one first... Any chance you saw that thread ? (I created a new thread for that issue..)

[Muz]

Theres been a major issue regarding red diesel at the back end of last year where the suppliers put in too much bio fuel and its caused major issues with prematurely blocked filters/ fuel starvation

Ive had a few and the filters looked fine, .. the blockage isnt like dirt, just premature waxing .. its been bizarre .. could that be a factor ? Remember always keep thinking simple first