Raw diesel smoke at startup

[sk66]

Relatively new owner of a 91 l300 2.5TD w/ 6v quick glow system.

I currently have the glow plugs running off of the 6v solenoid manually while the controller is being fixed (I replaced the leaking caps and jumped corroded traces, but it still wasn't working so I sent it out). At first start I have to run the glow plugs a bit, it seems almost irrespective of temp, but if I do it starts pretty clean. On a cold morning (~ freezing) if I don't run the glow plugs long enough (1-2 minutes, it seems like forever) I get a rough start with a lot of white raw diesel smoke which will all clear up in a minute or two... I suspect this is all fairly normal, is it?

However, when driving I never notice any smoke irregardless of load/throttle, and it seems a bit weak. I max out at about 110kph/70mph just under 3000rpm (unless going downhill). And it won't hold speed on any significant uphill grade (it will decay below 70kph/45mph pretty quickly), although I can accelerate uphill from lower speeds. The turbo has a replacement turbo controller that runs 15psi at minimum adjustment (linkage slop removed, maybe *slightly* tighter). Fuel economy seems a touch low at ~20 M/USG although there isn't much flat driving around here.

I'm wondering if the combined symptoms indicate retarded fuel pump timing? Or maybe just dirty injectors? Or the 15PSI boost causing a lean condition? Or is this all just the 2.5TD Delica?

TBF, my previous vehicle was a Chevy Avalanche with a 5.7L so the reduced power/acceleration is a big adjustment... but still, it's not even close to keeping up with the wife's 4cyl Jeep Renegade.

[Growlerbearnz]

The super-quick glow system has two solenoids- one feeds 12V to the plugs for the initial warmup, the other feeds 6V to the plugs (via the resistor pack) to keep the engine running smoothly when it first starts. The 12V feed is the one you want for the initial start from cold, 5-8 seconds should do, though you might get a bit of smoke once it's started since the computer's not cycling the 6V feed to keep the engine running smoothly. Try connecting your manual switch to the other solenoid and see if it helps, just don't hold it on for more than 10 seconds or so.

The lack of power (max 110kph is a bit slow) could be many things. I'd start with a general tune-up: rocker clearances, confirm timing marks line up, change fuel filter, change air filter. Check that the exhaust isn't plugged.

15psi is fine, I wouldn't change it or worry about being overly lean. Getting power from a diesel is mostly down to how much fuel is being injected, nothing bad happens if there's more air than necessary (unlike a gas engine). (Though it does give you some headroom for turning up the fuel screw once you've figured out what's wrong with the engine).

[sk66]

Thanks, rocker clearances huh... that will be last I think .

[sk66]

12v to the glow plugs works better, as expected... I originally just figured that using the 6v was more "foolproof."
Air filter looks about new/clean. Fuel filter ordered.

And now I've got a "cold weather" coolant leak... not entirely certain, but I'm pretty sure it's the water pump... and now it's getting to be winter and I don't have indoor shop space.
Oh the joys of owning an old vehicle .

[Growlerbearnz]

Thanks, rocker clearances huh... that will be last I think .

Don't leave it too late though. They're easy to check and adjust, and if they *are* wrong they can ruin the head.

using the 6v was more "foolproof."

It is, but it's slow- maybe too slow on an extremely cold morning. And if you're clever enough to wire up a manual switch you're not a fool.

a "cold weather" coolant leak

...Doesn't leak while driving, but there's a puddle of coolant under the van in the morning? Coolant appears to be dripping off the alternator or front of engine? Water pump. If you remove the lower engine cover and look upwards you'll probably see a drop of coolant hanging from the water pump itself. If you replace the water pump make sure that the alternator belts aren't too tight. (they're notorious for squeaking even when correctly tensioned, leading people to overtighten them, which ruins the water pump bearing. Ask me how I know.)

[sk66]

Most of the drips are towards the rear and from the transmission bell housing. But it appears to be running along the oil pan backwards. I see some evidence of water at the pump, and it's a cold engine only leak... pretty sure it's the seal going. I ordered a new Aisin water pump/gaskets... figured I'd go high quality as the price wasn't bad. If I get into it and find it's not the pump I'll have it for the next time the timing belts need done (belts were done at 92k and it has ~125k on it now... I guess they didn't do the pump or used a cheap reman). Only problem is 2-4 weeks to get it in... I'll just have to keep an eye on it or let her sit until then.

I assume the rocker cover has to come off to check the clearances... I suppose I should do that now since it's not too cold yet. The cover is leaking a little anyway and I already have the gaskets for it.

I just found out that, since I'm a vet, there's a post nearby with bays/lift/specialty tools I can use free of charge.

[Growlerbearnz]

since I'm a vet, there's a post nearby with bays/lift/specialty tools

Took me a moment to figure this one out. I was picturing:

EquineLift.jpg (183.19 KiB) Viewed 4487 times

[FalcoColumbarius]

Grins...

[sk66]

I was picturing:

Might be a good idea to have when you're driving a 25yr old Japanese import vehicle around.