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MISFIRE WHEN SLOWING DOWN.

Posted: 24 Jun 2011, 14:38
by MYBROWNBUS
Hello.
Can anyone please please help!
My old bus has a misfire when slowing down, loud bang then engine stall.
But it will restart ok and run well untill it decides to do it again.
Just had service. plugs,leads,rotor,cap,oil etc. Also changed the flange under the carb because it was spilt and sucking in air.
After this was done she ran like a dream even down to cornwall and back no probs .
But i got in her yesterday and once again load bang and engine stall.
Can someone please help i am gutted when i can enjoy my bus and its becoming a nightmare.

Re: MISFIRE WHEN SLOWING DOWN.

Posted: 24 Jun 2011, 15:15
by melmelody
hi there
this should probably be in the tech. mechanical section,but anyway. what type of engine? Aircooled? if so i think you may have a problem with your ignition amplifier unit. i had the same problem with mine.i dont profess to know too much about these engines mind you but there are some members on here that know pretty much everything about them and i'm sure will help solve your problem.good luk

mel

Re: MISFIRE WHEN SLOWING DOWN.

Posted: 24 Jun 2011, 15:39
by pocolow
Ahem....Intro first....Welcome to the club, let us know who you are ?where you are? which engine which year? then we may be able to help you.


Mark :ok

Re: MISFIRE WHEN SLOWING DOWN.

Posted: 24 Jun 2011, 15:48
by MYBROWNBUS
Sorry my name is Wayne and my wife is Naomi.
And we are the proud owners of a brown 1982 watercooled t25 called coco.
we have had cocco for 2 years now and have had tons of fun in her. We bought cocco after borrowing a friends devon after that we had to have one.
And we live in a small town called Highworth near Swindon.

Re: MISFIRE WHEN SLOWING DOWN.

Posted: 24 Jun 2011, 16:27
by MYBROWNBUS
Sorry i forgot to say it's a1.9 petrol.
Wayne

Re: MISFIRE WHEN SLOWING DOWN.

Posted: 24 Jun 2011, 16:57
by kevtherev
Seems like you have another leak by the sound of it...
Classic symptoms are backfire on the overrun

the leak causes a weak mixture and this weak mixture will not detonate in the cylinder (misfire) it then gets pushed into the exhaust where it eventually explodes.

Re: MISFIRE WHEN SLOWING DOWN.

Posted: 24 Jun 2011, 17:17
by MYBROWNBUS
Thanks Kev.
I was just looking around in the old girl just now.
I think after reading some of the advice that has been given, I am going to get out the wd40 and start spraying.
Hope it is a leak then i can get it sorted.

Thanks alot kev it's people like you and clubs like this that keep these magnificent machines on the road.

Cheers Wayne

Re: MISFIRE WHEN SLOWING DOWN.

Posted: 24 Jun 2011, 17:18
by big red bus
defo sounds like you got some kind of leak. Is the exhaust in good cond and not blowing?

Re: MISFIRE WHEN SLOWING DOWN.

Posted: 24 Jun 2011, 17:31
by MYBROWNBUS
As far as i can tell its all ok.
Just noticed that the flange i changed under the carb seems to have a split in it again.
just replaced it about a month ago. Can't understand why it's split.

Wayne

Re: MISFIRE WHEN SLOWING DOWN.

Posted: 24 Jun 2011, 17:39
by kevtherev
Do you mean the gasket to the inlet manifold?

Re: MISFIRE WHEN SLOWING DOWN.

Posted: 24 Jun 2011, 17:43
by MYBROWNBUS
Thats the one.

Wayne

Re: MISFIRE WHEN SLOWING DOWN.

Posted: 24 Jun 2011, 17:55
by kevtherev
that's quite a thick gasket :shock:

Re: MISFIRE WHEN SLOWING DOWN.

Posted: 24 Jun 2011, 18:10
by MYBROWNBUS
Yes it is .
it's metal covered in rubber, It just may be a faulty one from gsf.
When we changed it last time it seemed to stop it from backfiring. This could be the reason it starting to play up again.
I not sure if this is the reason but it has got what seems to be a split in it.
Because we changed it i thought that it was something else causing it.
I hope it is the reason as :ok it's an easy fix.

Wayne :

Re: MISFIRE WHEN SLOWING DOWN.

Posted: 24 Jun 2011, 18:38
by ghost123uk
Sounds like you have nailed the problem :)

Where possible buy stuff from Brickwerks = http://www.brickwerks.co.uk/index.php?p ... t&Itemid=3" onclick="window.open(this.href);return false; ) top quality parts and top quality service :)

Re: MISFIRE WHEN SLOWING DOWN.

Posted: 24 Jun 2011, 20:15
by MYBROWNBUS
THANKS FOR ALL YOUR HELP , WE WILL LET YOU KNOW HOW WE GET ON
WAYNE AND NAOMI.