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White smoke and misfire on start up ? i have the cure !!!!!

Posted: Sat Jan 29, 2011 6:56 pm
by M 80NGO
My Bongo had been suffering from the white smoke and lumpy tickover when started from cold for the last couple of months, so after reading other peoples posts i decided to do a little investigetion, when i turned the ignition on you can hear the click of the solenoid after a minuite or so, alls well there then, Next up i checked that i was getting voltage to the glowplug rail which i was until the relay clicks off, again all ok. next step was to check that the voltage on the rail was feeding the individual glow plugs, alls good there each plug getting 11.89v so i decided to order a new set of plugs.

Got them this morning so i took them out to the garage and tested that they all worked with an eath lead and a battery charger all glowing nice and redhot, Took the old plugs out of the engine testing each one as i removed it with the earthlead and battery charger i found that i had 2 good plugs 1 ok plug and one duff plug that got no heat in it at all.

I then fitted up the new plugs whole job took an easy 2 hours inc tea stops, once she was all back together and still stone cold i let the glow plug light go out and she fired up without and problems at all no lumpiness and no smoking, £32 in parts 2 hours labour and she's running like she should no longer does she deploy a batscreen on cold start =D>

Re: White smoke and misfire on start up ? i have the cure !!

Posted: Sat Jan 29, 2011 8:26 pm
by hembramacho
I had this issue last winter and in the end (and endless trawling and posting) accepted that it was just the way is was going to be. Had everything checked and even injection timing altered (and back again) and had a non return valve fitted on the fuel filter but it still did it.
This winter I've experimented a bit more and have come to the following conclusion:

If I turn the key and wait for the click (ignore the light going out) and fire it up as soon as it clicks, without touching the throttle at all, it's starts fine.
If I start it slightly before or after the click, or touch the throttle, that's when it chugs and smokes.
So in colder weather's that's what I do - works for me! :D
Sometimes in serious sub zero temps a few seconds idleing (without touching the throttle) before moving off makes a difference too.

Cheers

Andrew

Re: White smoke and misfire on start up ? i have the cure !!

Posted: Sat Jan 29, 2011 10:34 pm
by M 80NGO
hembramacho wrote:I had this issue last winter and in the end (and endless trawling and posting) accepted that it was just the way is was going to be. Had everything checked and even injection timing altered (and back again) and had a non return valve fitted on the fuel filter but it still did it.
This winter I've experimented a bit more and have come to the following conclusion:

If I turn the key and wait for the click (ignore the light going out) and fire it up as soon as it clicks, without touching the throttle at all, it's starts fine.
If I start it slightly before or after the click, or touch the throttle, that's when it chugs and smokes.
So in colder weather's that's what I do - works for me! :D
Sometimes in serious sub zero temps a few seconds idleing (without touching the throttle) before moving off makes a difference too.

Cheers

Andrew
When the relay clicks this shuts the power off to the glowplug rail, the correct start up method is to turn the key until dash lights come on, once the glowplug light has gone out turn the key again to crank the engine this ensures thet the glow plugs are still at max glow when the engine fires, as soon as that relay clicks off the glowplug power is cut and they start cooling down, maybe your plugs are just getting weak one of mine wasn't working at all.

Re: White smoke and misfire on start up ? i have the cure !!

Posted: Sun Jan 30, 2011 12:07 am
by bigdaddycain
Interesting posts! And a great outcome M80! =D> Now i'm not 100% clued up on all the in's and out's of the whole glowplug operation, but i can say from experieance with my own bongo that i too ignore the light, wait for the audible click, then do a slow deliberate turn of the key with NO throttle! Whenever i used to do the old recommended(?) half throttle on start up thing she'd chug and splutter like there's no tomorrow! Now, left ticking over, i think i'm right in saying that the glowplugs continue an on/off cycle for a few minutes even after the engine has fired up.... I have no clue as to what exactly switches that on/off cycle off (temp? revs? both?) But i wonder if some bongo's are more sensitive than others to being revved on cold start up? Mine sure don't like it [-X

Re: White smoke and misfire on start up ? i have the cure !!

Posted: Sun Jan 30, 2011 1:11 pm
by M 80NGO
BDC I can assure you that when that relay clicks it shuts power to the glow plugs, so if your waiting till you hear the click prior to starting up then the plugs are already cooling down where as if you fire it up when the glow plug light goes out then the plugs will still keep heating whilst the engine is running, on a cold morning you'd be better off letting the relay click then starting the cycle again turning the key as soon as the glowplug light goes off, i keep going out to mine and starting it up just to gloat at my victory over the smokey start up :lol:

Re: White smoke and misfire on start up ? i have the cure !!

Posted: Sun Jan 30, 2011 1:22 pm
by dandywarhol
The audible click is the relay shutting OFF, around 15 seconds after turning the key, depending on the temp. of the coolant.
On very cold mornings it's ok to leave the "ignition" on for a further few seconds to really heat up the air in the cylinders - but before the "click"
Once the engine has started, the relay keeps engaged for up to several minutes and will click on and off courtesy of turbo boost pressure cutting the relay out. I think the longest I saw the relay on was around 4/5 minutes on a v. cold day in slow moving traffic - I'd a led switch fitted into the circuit to turn the relay off earlier than the manufacturer wanted but if I kept the switch off I could still see how long the relay was feeding the glowplugs by watching the led light.

The glowplugs stay on for that length of time to cut down pollution in crowded Japanese cities - I don't mind gassing some of the inhabitants of Edinburgh's great unwashed :wink:

Re: White smoke and misfire on start up ? i have the cure !!

Posted: Sun Jan 30, 2011 1:52 pm
by rita
dandywarhol wrote:The audible click is the relay shutting OFF, around 15 seconds after turning the key, depending on the temp. of the coolant.
On very cold mornings it's ok to leave the "ignition" on for a further few seconds to really heat up the air in the cylinders - but before the "click"
Once the engine has started, the relay keeps engaged for up to several minutes and will click on and off courtesy of turbo boost pressure cutting the relay out. I think the longest I saw the relay on was around 4/5 minutes on a v. cold day in slow moving traffic - I'd a led switch fitted into the circuit to turn the relay off earlier than the manufacturer wanted but if I kept the switch off I could still see how long the relay was feeding the glowplugs by watching the led light.

The glowplugs stay on for that length of time to cut down pollution in crowded Japanese cities - I don't mind gassing some of the inhabitants of Edinburgh's great unwashed :wink:
Is that why they call Edinburgh, "AULD REEKIE". :roll: :roll:

Re: White smoke and misfire on start up ? i have the cure !!

Posted: Sun Jan 30, 2011 4:17 pm
by M 80NGO
All i know is that when i started my bongo up after fitting new glowplugs i was volt monitering the glowplug feed rail as soon at the relay clicks the rail instantly loses voltage.

Re: White smoke and misfire on start up ? i have the cure !!

Posted: Mon Jan 31, 2011 11:00 am
by teenmal
M 80NGO wrote:All i know is that when i started my bongo up after fitting new glowplugs i was volt monitering the glowplug feed rail as soon at the relay clicks the rail instantly loses voltage.

Hi,
After starting and running the vehicle from Cold the heaters should stay on for several Minutes until the engine gets to a reasonable running tempreture.If this is not happening you have a fault.


Cheers..

Re: White smoke and misfire on start up ? i have the cure !!

Posted: Mon Jan 31, 2011 10:42 pm
by M 80NGO
teenmal wrote:
M 80NGO wrote:All i know is that when i started my bongo up after fitting new glowplugs i was volt monitering the glowplug feed rail as soon at the relay clicks the rail instantly loses voltage.

Hi,
After starting and running the vehicle from Cold the heaters should stay on for several Minutes until the engine gets to a reasonable running tempreture.If this is not happening you have a fault.


Cheers..

There's defo no fault she starts and runs like a lill dream, i'll volt test it again this weekend but as me old grandad used to say
"if it aint broke, don't fix it" :wink:

Re: White smoke and misfire on start up ? i have the cure !!

Posted: Sun Feb 06, 2011 7:41 pm
by tallbongo
I have (well our Bongo has) the tough to start, lumpy idle and white smoke on starting in the cold.

The smoke and lumpiness suggests to me that its the glow plugs. I've checked the electrics first and I'm getting 11.6V to them until the relay clicks. Is this ok or should the voltage be higher? After the relay clicks off I'm not able to register the voltage switching on and off as others suggested should happen. What makes the relay switch back on and off?

The lumpiness and smoke stops as soon as I pull away, but while idling remains for quite a while, even after some revving.

Does anyone have any suggestions before I try taking out the plugs themselves? I'll have to invest in some new sockets for the job so want to check all I can before starting it. It doesn't look too hard, but quite awkward.

Re: White smoke and misfire on start up ? i have the cure !!

Posted: Sun Feb 06, 2011 8:03 pm
by M 80NGO
Its defo the glows buddy you don't need any special tools decent socket set from 7mm to 13mm and a flat blade screw driver to ease the two clips out and ease the vacum pipes off the bottom to the solenoid pipes, length of 2 x 2 wood to hold the seat propped up, took me 2 hours first time but i recon i could do it in half that time now i've done it already. if you have a jump lead fasten it to an earth under the bonnet ( i used the suspension strut bolt ) and as you take the old plugs out you can clip the other end of the lead around the glow plug and touch the top end of the plug on the live of your battery and it'll show which is the offending plug or plugs, if i was nearer i'd give you a hand to do em :roll:

Re: White smoke and misfire on start up ? i have the cure !!

Posted: Sun Feb 06, 2011 8:35 pm
by tallbongo
Thanks M 80NGO.

I'm pretty much convinced it's the glow plugs myself, but this is my first diesel. However, our local mechanic took a look and is convinced it's not. The plugs had been changed by the previous owner so he reckons it's electrical. He never charged though for his opinion so I doubt he actually took the plugs out and checked them.

Guess I'll have to invest in a long 12mm socket and take them out. Next weekend I'll take the fron one out to find out what size they are, order some up and do the job the following weekend. Is this a job where you should change them all at the same time, on the basis that if some have failed, the others are likely to follow soon?

Re: White smoke and misfire on start up ? i have the cure !!

Posted: Sun Feb 06, 2011 8:54 pm
by M 80NGO
I got mine from www.mister-solutions.co.uk part number 5116 85mm glowplugs NGK Y701-J £32.12 delivered, don't take your old ones out unless you have new ones to put in, yes they may have been changed before but did they use cheap ones.

:wink:

Re: White smoke and misfire on start up ? i have the cure !!

Posted: Sun Feb 06, 2011 8:55 pm
by wonkanoby
yes for sure