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Re: cold idling problems

To: Spitfire 1500 <s1500@uswest.net>
Subject: Re: cold idling problems
From: Vic Whitmore <vicwhit@home.com>
Date: Fri, 03 Aug 2001 09:52:13 -0400
I doubt the dashpot being empty would cause any rich condition. As I understand
it, the dash pot really only comes into play under acceleration/deceleration.

Even though you may have a nice idle now (running slightly rich), that part of
the carb is independent of the running circuit. The main jet and needle come
into play during normal driving (mid range and wide open throttle) and this may
be your problem. The needle vibrates around in the jet and causes it to become
oversized and oval. You will end up with a very rich condition while under way
(poor mileage, black around the exhaust pipe and rear bumper), even though the
idle is perfect.

You can lower the needle to correct it somewhat but the other part of the
driving ranges will suffer. The only long term solution is to replace the carb.

Vic Whitmore
76 Spitfire
Thornhill, Ontario

http://www.vicwhit.com


Spitfire 1500 wrote:
> 
> Well, I replaced the o-ring and holder for the dashpot thingy. It now safely
> holds dashpot oil. The old o-ring was rather wasted.
> 
> Upon starting it up though, I wasn't able to idle correctly from a cold
> start. Had  to keep it revved so the engine wouldn't die. I tried to richen
> the mixture but it didn't seem to do anything.
> 
> Eventually I upped the idle a litle bit, and it solved the problem(I think).
> The engine still runs a bit rough though. I checked for air leaks and such,
> and wasn't able to find any.  I tightened the conection on the carb from the
> fuel pump. The hose was a little bit out.
> 
> But when I drove it around at 30 mph it didn't seem so rough at all. I'm
> stumped on this one, and still concerned about the thirsy fuel consumption.
> 
> If the carb dashpot oil were to be non-existant(on a single Stromberg),
> would it give me lousy gas mileage since the dashpot would rise so high all
> the time, sucking in more gas?
> 
> Kids love the rich taste of web content!
> http://british.nerp.net

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