Warm vs Cold Start up - bit baffled

[403delica]

Yah I bought the vehicle from them! There wicked


Evan

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[Big-Bird]

Glow plugs do not continue operate after the diesel engine has started, they are on strictly to warm the cold air in the cylinders so that it can generate enough heat at compression to ignite the mist of diesel fuel introduced at the start of the ignition cycle. If they were still on the glow plug indicator on your dash would be lit.

There are a few things to check for sure.

Plugged,fouled injectors, washers not fully sealed at the head.
Poor seals in the injector pump.
Dirty or dusty air filters, even only partially restricted can cause low air flow that makes diesels run rough under load...not enough air charge creates a rich burn condition and incomplete combustion.
Summer rated fuel which tends to gel at lowered temps and also won't flow properly to support engine demands.
Fuel heater that according to a well versed Pajero owner may be malfunctioning or be weak.
EGR valve or blanking plate (if you have one) is leaking.

All of these are only suspects but the injectors and associated pump seals seem to be the main culprits when the Mitsu diesels misbehave.

[dfnder]

test

[psilosin]

Glow plugs do not continue operate after the diesel engine has started, they are on strictly to warm the cold air in the cylinders so that it can generate enough heat at compression to ignite the mist of diesel fuel introduced at the start of the ignition cycle. If they were still on the glow plug indicator on your dash would be lit.

On the L400 the glow plugs are ON for up to ~6 seconds and then after a successful startup continue to stay on up to 2 minutes after (controlled by ECU via coolant temp sensor). This is documented in many places and functions in part to decrease emmisions while the engine is cold.

The glow plug indicator lamp on the dash is not linked directly to the glow plugs or even the glow plug relay so is no indication if your glow plugs are actually active. It doesn't even stay lit for the full length of the time the relay is active pre-start. That lamp is controlled by another line from the ECU and is pretty useless as any kind of diagnostic (which is why people mod it).

[403delica]

yah the glow plugs will glow for a maximum of 3 min in the l400... the problem is it is not going to high idle... so when the glow plugs are done life is rough for the poor litle thing.... when the throttle is depressed before starting to engage high idle the idle leaver/ solenoid is not moving... or so it seems.

[Orionsbelt]

Ok...maybe I spoke too soon, runs great generally but that damn cold start seems to be a real nag. -5 and it's having some trouble to start when not plugged in - takes some cranking and that's after I've hit the glow plugs a number of times. I have a manual glow plug system which I tested recently along with the plugs -- all is good.

@Big Bird -- I'll check the egr blanking plate which I put in and secured pretty damn good. And used a good chunk of metal that's lined up just about perfect.
I have not heard of a "Fuel Heater". Where is that and can you fix them? Expensive to purchase / install?

Thanks, Orion