VERY smokey when cold - suggestions?

[Tribune]

So, the EGR delete, turbo boost increase (to 16 psi), PCV atmosphere venting, and intercooler install is finally complete! My 1991 Terrano TD27t runs like a dream now - way more guts when you put the peddle to the metal! And no black exhaust smoke at idle in hot weather either (probably via the PCV system).

What none of these mods have improved is the huge amounts of black smoke on cold starts with the choke* fully out. This is Canada, so when I say cold, I mean -5C and down to like -35C !!! The mods haven't improved it, but they haven't made it worse either though.

When subzero and the engine has cooled down it churns out huge amounts of black acrid smoke and is very rough for the first 30 seconds or so until settling down and the choke* being pushed back in. Black smoke is incomplete diesel combustion right? But the huge smokiness is very embarrassing, especially in urban or crowded areas or when around those who by nature disapprove of 4wd vehicles in the wilderness! When parked at home I'm either in a heated garage or have plug-in heat pads on the oil pan and a recirculating coolant heater that really helps. But out on trips or parked in the city at work I don't - and it smokes like crazy!!

So, is there anything that can be done (tweaks, mods) to reduce the amount of subzero starting smoking? I haven't adjusted the mechanical fuel injector pump in any way, so I'm wondering if adjustments could be made there. I'm also running the recommended volume of Powerup GEN49D winter diesel additive per tank of fuel - cleans injectors, increases cetane rating, prevents diesel gelling at cold temps.

*OK, it isn't really a choke in the petrol engine sense in terms of restricting air flow resulting in a richer fuel mixture, but rather advances the injector pump for cold starts. And yes, I am waiting until the glow-plug light goes out before starting!

Any advice you could give to a guy who loves his truck would be great!

[The Stranger]

I don't normally comment when I really have no knowledge of a subject, but. On the belief that black smoke is unburnt diesel, I would check glow plugs and consider a change of oil.
My experience is that different oils seem to make significant differences to the td27. Perhaps one will help improve compression and thus combustion when particularly cold?

[Tribune]

Yes, the glow plugs are top of the list for an inspection/test this weekend. As for the oil, it does need a change, but I've been running Chevron DELO 400 fully synthetic 5W40 since I got the truck 18 months ago. May be I should look at a 0W30 for cold climate running.

[andrew007]

i would check glow plugs.also glow plug timer.if all ok;i would suggest getting a timer like late toyotas which has after glows after the main glow.i think for about 1st 30 secs.have a talk to auto spark,they will no the one i mean.
cheers andy

[Cameron]

does it start fine without using the cold start timing thing? perhaps glow it twice and use a little throttle as an alternative?

[Tribune]

does it start fine without using the cold start timing thing? perhaps glow it twice and use a little throttle as an alternative?

Alright, finishing work and -2C out. Will try and start after a couple of glows and see if she smokes like an old freight train!

[tweake]

what IP are you running and what sort of cold advance system have you got on it ?

[hamboy]

Hey just a thought when you say "choke*" are you meaning the the little black knob on the left side of the steering colum? If so you may be trying to start it with full throttle as that knob lift the idle up. Try starting it with out pulling the knob out and see how it goes

[Tribune]

Hey just a thought when you say "choke*" are you meaning the the little black knob on the left side of the steering colum? If so you may be trying to start it with full throttle as that knob lift the idle up. Try starting it with out pulling the knob out and see how it goes

Yeah, that's the one. Tried starting yesterday after work. Didn't pull this "choke" knob out and cycled on the glow plugs 3 or 4 times. It wasn't that cold though, only -5C, but not black smoke and a smooth start and idle.

Left Terrano parked outside overnight without heaters plugged in. Will see how she starts this morning.

[quote="tweake']what IP are you running and what sort of cold advance system have you got on it ?[/quote]

Cold advance system is just the knob that looks like a choke to the left of the steering column - outline of the engine block on it. I'm a bit of a newby here so not sure what you mean by "IP". Other than that, just the regular 4 TD27t glow plugs. I did look on line and notice that some of the big pick-up trucks with high volume Cummins diesel power plants here in Canada run air intake or manifold heaters in addition to glow plugs for cold starts.

[crazyclark31]

don't think it needs any of that big truck stuff. The black knob is just a hand throttle so when you pull it out its the same as putting your foothard down on the gas pedal. try it without any "choke". the truck should be setup so you can glow it then just turn the key to start without any gas or "choke"

[Cameron]

Hey just a thought when you say "choke*" are you meaning the the little black knob on the left side of the steering colum? If so you may be trying to start it with full throttle as that knob lift the idle up. Try starting it with out pulling the knob out and see how it goes

Yeah, that's the one. Tried starting yesterday after work. Didn't pull this "choke" knob out and cycled on the glow plugs 3 or 4 times. It wasn't that cold though, only -5C, but not black smoke and a smooth start and idle.

Left Terrano parked outside overnight without heaters plugged in. Will see how she starts this morning.

perfect. if it's mega cold jsut make sure you plug in your block heater.
I reckon you've just got some knackered, or at least tired glow plugs. replace those, glow it twice on really cold mornings if you haven';t had your block heater plugged in. easy. bugger the hand throttle until it's actually running. that's there for negotiating rough stuff and raising the idle to help with warmup. I'd not pull it out to start the thing.

[tweake]

.

[quote="tweake']what IP are you running and what sort of cold advance system have you got on it ?[/quote]

Cold advance system is just the knob that looks like a choke to the left of the steering column - outline of the engine block on it. I'm a bit of a newby here so not sure what you mean by "IP". Other than that, just the regular 4 TD27t glow plugs. I did look on line and notice that some of the big pick-up trucks with high volume Cummins diesel power plants here in Canada run air intake or manifold heaters in addition to glow plugs for cold starts.[/quote]

IP means injection pump.
some pumps run systems which advances the injection timing when cold.
not having the hand throttle or idle up on will help. if you still have problems when its really cold it would pay to check what injection system its has.

[Tribune]

Thanks guys.

Glowing it three of four times without the "Choke"/hand throttle advanced really helps, but still a little smokey.

Gonna check out the glow plugs today. Got some spares anyway.

[Cameron]

ep. if you've got a dodgey glow plug it'll smoke heaps more when cold than if you've got a good set.