Starting a diesel

Neil_Sedaka

Can anyone tell me the correct way to start a cold diesel that doesn't have glow plugs?
It's a 2.5 transit.

Thanks.

JabbaTheHut

There's no pre-ignition chamber in a Direct Injection engine like the sort of one you're talking about,so it's just a matter of turning the key.Unless you have a different problem there

Neil_Sedaka

Hi Jabba,

it can be hard to start sometimes when cold, I suppose the question is really, to rev or not to rev whilst cranking?

JabbaTheHut

Pressing the accelerator when cranking won't make any difference to it.It has an "excess diesel" valve on the injector pump that operates when the engine is cold.It acts like a choke on a petrol carb.
Mind you,when it does start,reving it hard from cold would not do it good.Better to take it easy on it for the first few minutes.

sceptre

What are "glow plugs" then?

azezil

Originally posted by sceptre
What are "glow plugs" then?

diesel engines usually heat the fule b4 starting, eg meh fathers van on cold day a light comes on when he turns the key, after a while it goes off and the van starts.


... i think that's what it is anyway!

Neil_Sedaka

Originally posted by azezil
diesel engines usually heat the fule b4 starting, eg meh fathers van on cold day a light comes on when he turns the key, after a while it goes off and the van starts.


... i think that's what it is anyway!

That is correct azezil, there's no "spark" in a Diesel engine, so the fuel ignites purely from high compression, warm fuel will ignite easier.

Chimaera

diesel engines usually heat the fule b4 starting, eg meh fathers van on cold day a light comes on when he turns the key, after a while it goes off and the van starts

Erm, not quite - glow plugs heat the engine block so that engine will start more easily from cold - the diesel engine depends on the heat generated in the cylinder due to the compression of the air in it. If the block is cold, it'll draw away the heat the fuel needs in order to ignite. The glow plugs heat up the block around the cylinder head so that there is enough heat there for the fuel to ignite and start the engine.

SouperComputer

well kinda, the reason for a choke in a petrol car is the same as glow plugs on a diesel.

The fuel condenses on the cold cylinder walls and thus is no longer "atomised" and therefore it is harder to burn each molecule as it is not surrounded by air.

So, heat the walls, or richen the mixture!