Delica cold start problems, if not glow plugs then what else?

[AKcub]

I ran out of time for a compression check on Sunday. It is on my list for next maintenance day. I have a fuel filter enroute and plan on checking the finger screen on the IP banjo fitting while I'm in there.

It would be a guess related to the gp's but because I have seen relay/solenoids on aircraft fail in a mode that allowed the relay to close enough to provide voltage but only partial current I might try to figure out if I am getting correct current to the gp's. Seems like a pretty basic I=V/R computation but somewhere in the back of my brain there is a warning about DC resistance in a circuit screwing stuff up.

Thans for the input Growler

Growler,
Just so I understand the system- On a manual gp setup there is no need for the 6v solenoid?

Correct. It'll just behave like a regular one-shot glow system, without the additional gentle heat to ease the first minute of running. If you wanted to get really fancy you could add a second manual switch which operated the 6V relay, and then hold that down until the engine runs properly- but if you're going to that level of insanity you might as well just repair the ECU.

Edit- manual gp signal wire is connected to correct (inboard) relay...

Bugger. I'd be checking the compression next, and then finally the injectors' spray pattern. And then I'd run out of ideas.

[sealica]

I don't know why, but the owner's manual says that cold weather starts should be done with the accelerator pedal fully depressed. It's currently at freezing here and my 2.5TD starts w/o depressing the pedal.

I tried starting the van this weekend, 350 kms from home, and the van kind of sputtered and then stalled. I repeated that two times before giving it gas pedal while starting which fixed the issue . . . The temperature was around freezing, but I had started the van in colder temperatures in January without much issue other than very rough idle (corrected by using idle speed control to set ~1000 rpms).

I was kind of thinking well perhaps the glow plugs are in need of replacement, or of course the dreaded IP and all that, but why would it start in cold weather one day - not start in cold weather on another, except by pressing the gas pedal.

I'm just curious more specifically about the applying gas pedal while starting detail because while there is much info about the glow plugs / IP . . . I can't really find much to read about applying gas while starting? Should this be done? Can this be done? Does this indicate my cold idle is perhaps lower than it should be which is corrected by applying higher RPMs with the pedal?

Either way happy we were not stranded in the winterlands!

[sk66]

I'm just curious more specifically about the applying gas pedal while starting detail because while there is much info about the glow plugs / IP . . . I can't really find much to read about applying gas while starting? Should this be done? Can this be done? Does this indicate my cold idle is perhaps lower than it should be which is corrected by applying higher RPMs with the pedal?

Either way happy we were not stranded in the winterlands!

I really don't know... It could be required to get a good fuel/air ratio as cold air is much denser. It might also help get better fuel atomization through the injectors which would allow it to ignite easier.

[sealica]

Hmmm, very curious, because this issue has been recurring over the last few starts.

The temperature has dipped to -1 overnight, but it's not overly cold like one start I managed with all water bottles in the van frozen from the previous night (except a few I had wrapped in blankets) . . . this is what perplexes me that start was about a month before and it was at lease -5 if not -8 overnight; however we didn't start the van until later in the afternoon in contrast to early morning (5 AM - 9 AM) ... perhaps that obscured the issue.

I'm able to start the van with the gas applied, but I don't think it would stay running if I didn't press the gas. The idle is really rough and stutters when cold, but once the thermostat opens the idle smooths out. I've been doign some research, but just running in circles - I just can't find much of a consensus on pressing the gas while starting a diesel; especially not a 4D56T . . . it seems to suggest the issue is fuel rather than glow, but I don't find any other issues like power, diesel leaks, or black smoke. Enigma!

I guess it's just a matter of going through the motions and testing the glowplugs, IP, and ECU - but it seems weird that the pedal "fixes" the issue. Of course once spring actually hits the issue will disappear only to reappear next winter ;) leaving me paranoid while out in the bush :p

[sealica]

I guess my major concern is whether forcing the van to start via injecting diesel with the pedal while starting possibly doing any damage like making the engine start with cold fuel or somesuch? It kind of feels that way like the first several cycles are excessively rough ...

If the owner's manual says to do this then I guess not, but I actually couldn't find an owners manual for the L300 - just the shop workshop manuals.

[Growlerbearnz]

I've been thinking about this one:

In our primitive engines when diesel is injected there's a mixture of tiny droplets and larger ones. The tiny droplets burn first in the precombustion chamber, and the heat from that breaks up and ignites the larger droplets. Prior to ignition you get a few tiny droplets from the injectors directly, but most of them come from the hot air in the precombustion chamber swirling, heating, and breaking the larger droplets up.

If the engine's cold, the injected charge is less likely to break up into smaller droplets. Cold diesel is more viscous, and the swirl in the precombustion chamber isn't as energetic. By using the accelerator you're just injecting more fuel, and increasing your chances of getting enough fine particles to actually ignite. It's not pretty or efficient, but it works.

Don't worry about damaging the engine. The stresses it has to handle when hot are higher than when it's cold. The first 30 seconds of running might not be pretty, but it's not going to hurt anything.

[Killbert]

Hey, classic issue so it seems. I have the same terrible cold starts. Just to confirm, with the manual setup, all we want to do is drop the switch along the signal wire from ports B OR E? Should we have a fusible link in the way? 10A?

Also, to add to this, my relays go mental after the van is warmed up. Rapid fire clicking, nothing sequential, just random on/off in a beserker fashion. I just replaced the temp sensor. Any thoughts on the epileptic glow system?

Thanks!!

I just had this happen for the first time yesterday. Insane clicking during warm operation. I'm opening up the ecu next weekend to look at it.

Sent from my SAMSUNG-SM-G891A using Tapatalk

[ynwa]

I just had this happen for the first time yesterday. Insane clicking during warm operation. I'm opening up the ecu next weekend to look at it.

Sent from my SAMSUNG-SM-G891A using Tapatalk

Hey! Ya, I had mind apart and noticed an 'area' of discolouring, I cleaned it up a bit but couldn't determine an obvious trace or blown resistor or capacitor. Something is definitely up, since the glow sys sometimes doesn't engage, but is usually fine first thing in the morning. Seems to be when things are 'warmer'. Good luck, keep us posted!

[Killbert]

I just had this happen for the first time yesterday. Insane clicking during warm operation. I'm opening up the ecu next weekend to look at it.

Sent from my SAMSUNG-SM-G891A using Tapatalk

Hey! Ya, I had mind apart and noticed an 'area' of discolouring, I cleaned it up a bit but couldn't determine an obvious trace or blown resistor or capacitor. Something is definitely up, since the glow sys sometimes doesn't engage, but is usually fine first thing in the morning. Seems to be when things are 'warmer'. Good luck, keep us posted!

Good to know. Thanks for the uodate.