L400 2.8 diesel rough cold start - UPDATED

[stever1000]

When I start my L400 in the morning, or the first time of the day, it is really rough for the first few seconds, idles low (500rpm) and shakes the vehicle. I just purchased it through an old member and he had the IP seal replaced, and the glow plugs have been replaced within the last couple of years too. It has a brand new Edmonds battery and starts immediately. If I step on the accelerator to 1500rpm for a minute and let it "warm up" it idles better. It does not stall or give me any other problems other than the first 30 seconds. But it still concerns me...

It has sat for a few weeks without being run regularly, and I am wondering if this has anything to do with it. (PO's insurance ran out Dec 4, I purchased and insured it mid-Jan).

Any suggestions on what I can do/look at? It's weird because it is only the first 30secs-1min when starting and it doesn't give me troubles after.

UPDATE:

I paid closer attention to starting it today. I stood outside the vehicle and waited 30secs for the glowplugs to do there thing. It turns over fast, however it idles low and sounds like it is struggling, shaking hard, with white smoke coming out the tailpipe. I can push the pedal to 1000-1500rpm and more smoke will come out, then it will settle down and no more smoke will come out.

From what I understand, white smoke is unburnt diesel that passes into the exhaust.

It only does this when it has been sitting over night. If I start, stop, then start it again, it's fine.

Thoughts? Is the white smoke connected to the struggling start?

[Big-Bird]

Glow plugs don't last forever. 2 yrs is exceptional.

Pull the glow plugs and test them either with raw battery voltage for a heat cycle or with an ohm meter(resistance) all it takes is one bad plug to create a hard start condition.

Once the engine is warm,.even after a few hours the 2.8 starts easy and runs well.

[stever1000]

I threw out that time as a guess. Besides the glow plugs, what could it be?

In the meantime I will look into the glow plugs.

Thanks!!

[FalcoColumbarius]

Glow plugs don't last forever. 2 yrs is exceptional. ...

I've had my plugs since before 2008 (January). Still working fine, OEM Super Glows (green tops).

Falco.

P.S.: Sorry, didn't realise you're talking 4M40, I'll move this topic to L400 Tech.

[Big-Bird]

Falco: From everything I have read about the L300 and L400 diesels specifically about the glow plug systems is they don't operate the same way and there are plenty of Aussie posts on this subject. I have accepted the fact that GLow plugs after 6 months should be checked for proper operation and replaced when the readings start to dip.

I would love for glow plugs to last more than a year! Hasn't happened yet and I have tried all types in the last 3 years including the venerable green tops. If my experience is the exception then so be it. My Pajero pals change plugs anywhere from 12- 16 months as thats when they seen weakness in their own systems.

[FalcoColumbarius]

Yes, they are different. The Super Glows are 6.2V and the 4M40 GPs are, I think 11V, but resistance is still the same principle. I've always cycled my plugs, whether the engine is cold or warm and after seven years ~ the love is still there. So is my ECU.

Falco.

[stever1000]

I paid closer attention to starting it today. I stood outside the vehicle and waited 30secs for the glowplugs to do there thing. It turns over fast, however it idles low and sounds like it is struggling, shaking hard, with white smoke coming out the tailpipe. I can push the pedal to 1000-1500rpm and more smoke will come out, and it starts to sound better, then it will settle down and no more smoke will come out.
It only lasts about 30seconds from when its start until it idles smooth and zero smoke.

This is taken from a different thread but similar topic...
http://www.delica.ca/forum/hard-cold-st ... -3653.html

White smoke is a sign of water vapor or fuel that has been atomized but not burned. The water vapor may be present in the fuel or water may be leaking into the cylinder from the cooling system. Air in the fuel can also cause white smoke.

(emphasis added)

any small air leak in to the system can cause both hard starting and white smoke...

The person above fixed their problem by buying new glow plugs. I will pick up a multimeter and check the glowplugs this week. In the meantime...

This is my first diesel, and from what I understand a little white smoke is normal for diesels when they are started cold. I'm just hoping it's not something serious because I just bought it a couple of weeks ago.

Is what I wrote common symptom to a faulty glow plug?

Thanks!

[doodah]

Sounds like a typical cold start for a Delica l400...

[Tojo]

Sounds a lot like my start.

Today it was -2 degrees celcius. Cycled the glow plugs twice, waiting 10-15 seconds between the cycles. Cough cough, sputter, a single belch of black smoke, white smoke for 15 seconds, settles down a bit after 30 seconds, then hold at 800 rpm. If I hold it at over 1000 rpm then it will skip a few beats here and there, so I warm mine up under 1000 rpm. Another couple of minutes and I'm ready to drive away under light load, gentle on the throttle until the engine comes up to running temperature. At -20 degrees it's a lot rougher but still starts. Ahhh diesels.

FYI my vehicle has an oil pan heater plugged in for 3 hrs before starting in the morning, no block heater yet, no inline coolant heater yet, new glow plugs, dual batteries are 1 year old, 0W30 Rotella T6 synthetic oil for winter only, air and fuel filter are overdue for changing. Using a fuel additive for winter.

[stever1000]

It's not cold here is what I am confused about, it's around 10*C when i start, and every morning, it sputters, hesitates, blows white smoke, then finally settles down after a bunch of white smoke

[tonydca]

In my experience, when everything is running correctly it will start up perfectly on the first or second crank. No white smoke, no lumpy idle, nada.

If you have tested the glow plugs and their connection to the busbar linking them together (!!), then I would suspect air is getting into the IP, despite your claim that the previous owner had it rebuilt.

As a test, some time when you have been driving the vehicle for a while and it is running happily, pull over and pop the hood. On top of the fuel pump (passenger side near the rear of the engine compartment) is a plunger which is used to prime the fuel pump and force out any air which might be present. Try to press down on that plunger and feel the (hopefully high) level of resistance to motion. That is the "normal" way it should feel.

Now first thing in the morning (when it has sat for a while and you predict a crappy start), pop the hood and give that same plunger a push. If is pushes down more easily, release it and repeat until it gives serious resistance to being pressed down (like in the previous paragraph).

Now cycle the glow plugs for their typical 5-8 seconds (listening for the glowplug relay to click on then off again) and if it starts up more happily than you'd expect, that would be a pretty sure sign for me that air is somehow getting into your IP.

[Firesong]

Might be the injectors.

[DexterH]

I used to have a very hard start for my first startup of the day. This was in the earlier days when I first bought my L300 from a friend who owned it from new for 13 yrs or so. I was new to the 4d56 and this was my first of many issues.
Anyways, turned out the hard start-up/rough idle/white smoke was caused by a bad primer pump. Replaced it with a used one and the problem was solved.

I wondered if a bad solenoid could cause such a rough idle or hard start if it isnt opening fully to allow sufficient diesel flow? Eventually as it warms up as the engine idles, perhaps heat allows it to open more, thus a better idle.

I welcome your thoughts on this.

[tonydca]

I remember something I posted in an earlier thread about lumpy starts and checking for faulty glow-plugs vs. other issues:

As a rule of thumb check, a faulty glow-plug will likely result in a chugging startup when cold, but a rhythmic one ('cuz it's the same cylinder failing to fire each time: chug-chug-chug-chug), where systemic things like glow plug relay, bussbar, IP seal, etc. will make a more random stutter when it's having trouble because it's a failure for all cylinders to reliably fire (chug-chuggity-chug-chug-chuggity-chuggity-chug). Does that make sense?

I too had problems with HKT plugs, but knock-on-wood, my Hyundai replacements are working well 2 years in.

One thing to note - I think it is wise to replace all four at once if you do find out that one or more is/are starting to go. All plugs should have the same resistance to draw the same amount of current, and mixing new plugs with old may cause some to be running hotter than others if they differ.