Thread: Marmalade the IIa

Originally Posted by Ypsilophora

but on one rotation it seems slightly easier.

okay I lied, just as bloody hard on every cylinder.

adjusted the slow running screw up a little (some fool had turned it nearly completely out), it now idles much much more smoothly.

getting white acrid eye burning smoke (unburnt fuel I assume), and a random miss (at idle it seems to be once every second or two, sometimes more sometimes very rarely).

To me this seems like a fuel delivery issue? I would think low compression would cause continuous missing?

Cheers.

Sounds like one injector is not working quite right at very low fuelling. As you say, compression would tend to be constant, although I can envisage ways it might not be, for example, a valve that sticks occasionally, but these would seem unlikely.

Could be one injector is giving a poor spray pattern at very low deliveries, and this pattern is just on the margin of sometimes igniting properly, sometimes delaying slightly.

You can test which cylinder is involved by cracking a union on one injector while it is running, and changing the occasional miss into a regular miss - but any other cylinder except the faulty one will still have the erratic pattern as well as the regular miss.

Hey John,
Thanks for all your help along the way.

Still having trouble with the engine, I suspect it’s still a fuel delivery issue:

After trying to adjust the timing yesterday, with an improvement in the smoothness of the engine, but no change to the smoking issue, I noticed no. 4 injector seemed to be leaking diesel. At first I assumed it was the fuel pipe connection, but after fiddling around with that it became evident the join was sealing fine. It seemed to be leaking from the head (squeezing past the sealing washer and up past the injector nozzle). I pulled that injector and replaced the crush washer + copper washer. This seemed to make a pretty big difference to the smoking issue, and the engine sounded even smoother than before.

I then took it for a quick drive around the property, and after around 30 minutes the smoke had completely cleared up, with the exception of a slight puff after blipping the throttle (as the revs dropped again). BUT THEN I noticed it started to ‘clatter’. not under load, mainly when idling.
It’s not a rhythmic noise as I’m used to hearing from a knocking engine (not that I have had much experience, but have been around one or two), it’s also more of a ‘clatter’ rather than a ‘knock’.
It’s also started leaking from the injector seating, and it’s started smoking more consistently (still seems like unburnt diesel).

My question is, is it even possible for the injectors to leak back up through the injector ‘hole’? And would this cause a clattering/knocking?

It’s all a little frustrating

Oddly, despite all the issues I’ve never had any trouble starting it. Even without glow plugs, I kind of assumed any fuel delivery issues would make it difficult to start.
I even accidentally started it we bleeding the last of the air to the injectors (I had the one of the injectors slacked off. It did run horribly though, so that injector probably isn’t too suspect)

I’ll attach a photo of where the diesel ‘pools’ after a few minutes of running. The fuel pipes and whatnot all stay dry though.

Can't tell from the picture where that is coming from, but if it is not coming from the pipe and connection, it has to be coming from a leak somewhere on an injector.

These engines, unless they have poor compression or all injectors in poor condition, will usually start easily except in very cold conditions without heater plugs.

Are you sure the chatter at idle is not from the gearbox (foot on clutch will solve that one!). About the only things in the engine likely to "chatter" is the timing chain or a loose precombustion chamber. (Assuming you can identify tappet noise)

Originally Posted by JDNSW

Are you sure the chatter at idle is not from the gearbox (foot on clutch will solve that one!). About the only things in the engine likely to "chatter" is the timing chain or a loose precombustion chamber. (Assuming you can identify tappet noise)

I don’t think it’s tappet noise, as I didn’t think it was there when I first started it yesterday. It could be that I am overthinking it a little - if it was the tractor I probably wouldn’t even think twice, I may be being a little precious of it because of the amount of time I’ve spent!

A friend who is more knowledgeable of these engine is coming round tomorrow, hopefully he’ll be able to have a listen and help me out!
At the moment I’m quite tempted to just accept it and fully rebuild my spare engine, then drop it in. Will give me the experience of rebuilding one completely, as well as removing a few ‘unknowns’.

Cheers
Luca

Things are now nearing registration point, probably a good month of still (possibly more, I’m getting better at not underestimating time frames!).



After chatting with someone who knows these engine quite well, I feel a lot better about how the engine runs. He reckons the injectors are probably just a bit dodgy, but if I sort them, most of the smoke issues will likely burn off after running it on the highway for a bit.

I need to paint the tail gate at some point, but I’m a little over sanding at the moment!!!



I’m pretty pleased that it actually isn’t leaking much at all, I was expecting it to be worse than it is... actually I should go double check I’ve filled it with oil....... 🧐

One point I note in the above picture you need to think about re registration. Those tail lights are 90/110/Defender, and differ in a key respect from Series lights - they do not include a reflector - the later vehicles have a separate reflector. For registration you need to have rear reflectors. You can either install the correct lights - hard to find, and even harder to ascertain exactly which ones were fitted - they varied, and not just over time but where it was built - and will be expensive. Separate reflectors are cheap and readily available.

My 2a has both the correct lights (it is Australian army, hence different to the contemporary civil version!) and separate approved reflectors, installed just above the crossmember each side.