hard cold starting tip for Weber carb petrol models

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B-Hive
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hard cold starting tip for Weber carb petrol models

Post by B-Hive »

I realise that the majority of the forum's members are either Oilers or 16vers..but I thought I'd post something to watch out for when diagnosing and rectifying difficult cold starting on a Weber petrol car...

The back story is that my first TRS16 auto always ways very hard to start when cold, despite my fitting of an electric choke device.....
it use to have an auto choke,, but it was dead...

So when I got the GT I was delighted that it had the holly grail manual choke, and once sorted she now starts first time with barely a full crank..Just pull full choke...no throttle..and bang she fires

So I was kinda expecting the same from my recent new TRS 5 sp, manual choke..

Not to be. as she continued to be a pain to start cold...UNTIL yesterday when I noticed that even on full choke that the choke flap was still slighlty open..

Initially I thought this wouldn't make any difference, but as soon as I pushed the flap fully closed with my finger she fired immediately..

I decided that the linkages and shafts on the carb were stiff and so liberally applied WD-40...This cured the problem as the choke flap was now fully closed with a full fist of the choke knob..

Now she kicks from cold perfectly almost as instantly as the TRi.. Very cool

This got me to thinking that this was my problem all those years with the old TRS auto, in as much as when I installed the electric choke device, I had set it conservatively that "full choke" wasn't ever quite fully closed .. almost identical flap opening to my current TRS that I just fixed..

So moral to the story, even if you think your choke is actuating, ensure that the choke flap closes FULLY for cold starts..and dont touch the throttle...

I hope this is useful info for all other gasoline carb cars...I think the same may apply to all Solex fitted cars as well..
Current
85 BX GT Mk1..
86 BX TRS Mk1
87 BX TRi


Gone
85 BX TRS mk1 auto... SOLD
90 BX TRi..parts....cubed
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Way2go
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Re: hard cold starting tip for Weber carb petrol models

Post by Way2go »

2BXORNOT2BX wrote: I decided that the linkages and shafts on the carb were stiff and so liberally applied WD-40...This cured the problem as the choke flap was now fully closed with a full fist of the choke knob..
WD40 is not a lubricant, so not ideal for a long term fix. Better using 3in1 Oil for linkages and if they need extra freeing up first, use 3in1 penetrating spray.
1991 BX19GTi Auto
citronut
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Re: hard cold starting tip for Weber carb petrol models

Post by citronut »

this is very strange as

if memory serves the choke is meant to be set very very slightly open on BX's with auto choke,
i belive there was once a mod in a techy bulletin from citroen many moons back, showing to drill a small holl in the choke flap/butterfly,

if you watch the choke flap on cranking a petrol BX the vacuum capsule opens the flap slightly anyway,
that is if its all set up correctly,

the usual hot or cold start prob petrol BX's have is the choke fully closed strangling the carb

regards malcolm
Last edited by citronut on Thu May 02, 2013 8:49 am, edited 1 time in total.
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Tim Leech
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Re: hard cold starting tip for Weber carb petrol models

Post by Tim Leech »

Do you get "cold" where you are, or is it just a little "chilly" as we would say? :mrgreen:
Lots of Motors, mostly semi broken....
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