Outer Limits 4x4 Board

This is a question for all you diesel gurus out there; about a month after I bought my 99 diesel triton last year it started to cough out white smoke on start up when cold and would idle roughly (to the point where I would have to use the hand throttle) until warm. 6 months later and its still does this. Concerned I had my glow checked (ok) and my injectors serviced but with no improvement. I been reading up on the problem in other threads and there is mixed opinions about the problem. Some say it's common and not a problem, while others say it could be one or all of the following:

injectors need servicing (done that and it doesn't blow any
smoke apart from start up)
one glow plug not fuctioning (checked and ok)
water vapour in fuel
head problems
fuel pump problem
timing out
dirty fuel

The triton had 108 000k's when I bought it (122k now) the only thing I can come up with is that the timing belt wasn't replaced at 100k and is causing the problem (which I plan on doing ASAP). The only thing that prevents this is to heat the glow plug up 3 or 4 times before starting or leaving the hand throttle turned up. By doing this am I covering up what is a serious problem? Love to hear people's opinion about this mystery.

P.S. Sorry about the huge amount of text but I know how important it is to have all the information before making a diagnosis.

White smoke is unburnt fuel,
incorrect starting procedure.?
Lack of compression.?
J Top

If it is a lack of compression wouldn't that mean that it would blow white smoke after start up as well?- which it doesn't. J Top can you explain for this novice what you mean by incorrect starting procedure and what it may relate to mechanically- wise? Thanks for your thoughts

Gee

Not sure how the Mitsubishi diesel start procedure works but on Toyotas (model dependant ) there can be a period of delibrate overinjection (= excess fuel supplied) during warm up on a cold engine. Temp sensor detects wether the engine is cold or already warm etc.

Check out the manual for your vehicle or maybe one of the Mitsubishi gurus can answer this for you.

G'day Gee,

Definately sounds like a glow plug problem..... (maybe made worse by a stretched old timing belt)

You say you had your glow plugs checked?? How? just the usual resistance test, or more detailed. IMHO if they are original, then throw them away and buy some newies, they have had their day.

you also need to check that they are staying on long enough, and that the temp sensor for them is working for them, because if it is faulty it could tell the controller the engine is still warm and does not need the plugs as long. (the workshop manual should tell you how long before and after startup they stay on.)

Another 2.8 prob that i have come across a couple of times now, is the wiring the the glow plug rail either works loose and/or burns out reducing the needed amperage to the plugs. so still tests 12+ volts, but needs to be visualed for damage etc where it attatches to the start of the rail.

Rob

4runna, the glow plugs are original and I assume that they were just given a resistance test- is it common for these test to show that the plugs are ok when they're not? I think I probably should get them replaced. Is it possible that the battery or alternator are playing a role in the glow plug(s) not heating properly?

Gee

Gee

I'm far from an expert on diesels, but if the white smoke is caused by unburnt fuel during the start-up period then the timing belt could be an issue if it also controls injector timing. If the belt has stretched and retarded the injection timing then effectively your engine is running retarded (losing power) and has less time to burn the extra fuel injected while cold. Retire your timing belt before it quits, then see what happens.

It also occurs to me that Mt Isa probably doesn't get real cold (but please correct me if I'm wrong. ) If the glow plug check only tested resistance, and not the voltage feed, then maybe they're not working and it's only Mt Isa's warm climate which allows the vehicle to start at all?

Good luck,

Scott

Thanks for all the info fellas, the plan is to get the timing belt done and new glow plugs. Hopefully that will solve the start up issues- if not expect a new post asking for more suggestions. And Scott your right about Mt Isa being warm- I been here 2 months and the lowest minimum daily temp. so far has been about 25 C.

Cheers,

Gee

Yes I have seen them test fine (within spec) yet when replaced there was a noticeable difference!

for the sake of $40 it's well worth it with that many kays on them, about due for change anyway. so even though they're working it is probably a combination of that old belt (therefore timing a bit retarded) and old glow plugs.

for your interest sake do 1 thing at a time and try it so you know what the actual problem was.

BTW, much of a diff with your injector service overall (economy or power) ??

Rob

Rob, to be honest if there was any improvement in power or economy I didn't notice. I was hoping that it would stop the start-up problem based on an article I read in 4x4 Australia (Sept 2004) on buying used Navaras where they made mention that white smoke on start up means your injectors need servicing. Obviously it didn't solve my problem but at least I won't have to touch them again for another 100k (fingers crossed). The triton has never blown any black smoke, maybe if it did the servicing may have reduced black smoke.

Gee

Update: Today I bought a battery and alternator tester. Battery OK, Alternator NOT. With the engine idling and no lights on or anything the tester was saying that the alternator is fine and charging. As soon as I turned on the head lights, spotties or aircon the tester was saying it was not charging. I tested it about four times with the same result- I also tested it on my wifes Pulsar just to be sure the it wasn't faulty and it was saying that the pulsar's alternator is fine and charging both with and without all electrical components turned on.

Could the white smoke on start up be related to the alternator ie. glow plugs not heating?

And doesn't anyone know what this information about the alternator means? Is it faulty? Or is it struggling to put out enough amps for all my electrical accessories (keeping in mind the tester was indicating that the alternator wasn't charging with only the head lights on).

Any thoughts?

Gee