mis-firing when i start it up

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kinghassan

mis-firing when i start it up

Post by kinghassan » Sun Jan 18, 2009 10:52 pm

Hi all ,
when i start our bongo it mis-fires a little and spews out some white smoke, its fine after its warmed up any ideas what this is and if it is serious or not?
also its due for its MOT next month and i've been told it needs a middle exhaust box as it has a hole (fair enough) i got quoted about £160 (not including labour) from a mazda dealer for a mazda exhaust. is it worth paying this or shouls i get a cheapie?obviously the labour costs will be higher at the dealer any one got any thoughts on this.
cheers!!!
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missfixit70
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Re: mis-firing when i start it up

Post by missfixit70 » Sun Jan 18, 2009 10:55 pm

Glow plug or plugs?, check the relays working & the rail's getting power, loads in techie on it if you do a search on "glow and plugs" . Not scary or expensive.
Go for a cheaper exhaust, not a mazda rip off, whereabouts are you? A local recommendation may come your way if you update your location in your profile by clicking on "user control panel" top right.
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Re: mis-firing when i start it up

Post by kinghassan » Sun Jan 18, 2009 11:25 pm

thanks for that kirsty and i'll check the glow plugs!
scanner
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Re: mis-firing when i start it up

Post by scanner » Sun Jan 18, 2009 11:32 pm

White smoke (not steam or condensation) is sometimes wrong injector timing leading to vapourised, but unburnt, fuel being exhausted.

Diesels need advanced timing (I think) when cold to allow more time for combustion and if they don't get it, spew out any unburnt fuel as vapour.
Last edited by scanner on Mon Jan 19, 2009 12:24 am, edited 1 time in total.
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The Great Pretender
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Re: mis-firing when i start it up

Post by The Great Pretender » Sun Jan 18, 2009 11:51 pm

kinghassan wrote:thanks for that kirsty and i'll check the glow plugs!
If you intend keeping the Bongo, as part of the exhaust is on the way out why not consider a stainless system?
If my memory still works think there were posts on here of full systems fitted for around £300.
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Re: mis-firing when i start it up

Post by kinghassan » Mon Jan 19, 2009 12:10 am

the back section was replaced 6 months ago at a costt of 230 (he got done at kwik fit) quid to the last owner so i'd prefer to only do the centre section.
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mikeonb4c
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Re: mis-firing when i start it up

Post by mikeonb4c » Mon Jan 19, 2009 2:52 pm

scanner wrote:Diesels need advanced timing (I think) when cold to allow more time for combustion and if they don't get it, spew out any unburnt fuel as vapour.
Thats interesting scanner. In the absence of a spark to advance, how do diesels do this? I have often wondered about how the diesel equivalent of ignition advance might work.
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Re: mis-firing when i start it up

Post by scanner » Mon Jan 19, 2009 3:13 pm

It's just done by advancing the injection timing, the pump has a cold start device (just like an auto-choke on a petrol) on it which works off the water temperature.
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mikeonb4c
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Re: mis-firing when i start it up

Post by mikeonb4c » Mon Jan 19, 2009 7:03 pm

scanner wrote:It's just done by advancing the injection timing, the pump has a cold start device (just like an auto-choke on a petrol) on it which works off the water temperature.
Ahhh! Feindish clever these Japanese - eh what Fawlty?
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Re: mis-firing when i start it up

Post by scanner » Mon Jan 19, 2009 10:19 pm

mikeonb4c wrote:
scanner wrote:It's just done by advancing the injection timing, the pump has a cold start device (just like an auto-choke on a petrol) on it which works off the water temperature.
Ahhh! Feindish clever these Japanese - eh what Fawlty?
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:lol:
Psst - it was probably (the) Bosch that thought of it first - don't mention the war though.
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