340 - Carb problem - 32 DIR 109

D24Tdavew · Dec 15th, 2004, 22:06

My 340 is fitted with a Weber 32 DIR 109 carb.

When it is started I use full choke and no accelerator as per the manuals recommendations.

As soon as the engine starts, and if the accelerator is untouced by me, the revs drop and the engine typically stops.

I can usually get round this by pumping on the accelerator when I start the car, and once started the car runs quite smoothly.

Before I strip the carb to investigate float levels etc, I wondered if anyone from this forum has experienced anything similar, and if so what you found the fault was.

Regards to all

Dave
D24Tdavew

Dec 15th, 2004, 23:39

Mine does that

One pump of the accelerator before you turn the key and it's happy but it needs the choke gradually reducing over the first 20 seconds or it chokes itself to death as it warms up and the mixture becomes too rich, and I fitted a new carb last year. I suspect its the settings, not a worn-out carb (as mine is new).

Or it could be an air leak between the carb and the manifold...

You aren't supposed to change the fast idle speed but it does sound like the fast idle isn't fast enough? Anyone else?

D24Tdavew · Dec 16th, 2004, 00:16

Thanks for that John.

I did increase the fast idle(still keeping it within spec) to try and overcome the problem, but to no avail.

I am thinking in terms of the float height, or even a perforated float. It seems to point to a lack of fuel.

I'll take off the carb in the next week or so and do some checks and if anything turns up I shall reply to the forum.

Many thanks

Regards

Dave
D24Tdavew

Dec 16th, 2004, 10:16

http://www.volvo300mania.com/forum2/...0-360-f571.htm

D24Tdavew · Dec 31st, 2004, 21:29

As a follow up to the query mentioned, I would confirm that the fault has been found.

I obtained a Weber Refurb kit and replaced all main diaphragms and the needle valve etc, in fact all the parts typically in the kit.

The diaphragm called the Starting Device Diaphragm had a small hole in it.

This forms part of the pneumatic choke control, and opens the choke valve as soon as the car starts.

The engine now starts as you would expect on every cold start.

Many thanks for the comments made.

Regards

Dave
D24Tdavew

Dec 15th, 2004, 22:06	#1
D24Tdavew Junior Member Last Online: Aug 28th, 2007 22:15 Join Date: Dec 2002 Location: Stourbridge	340 - Carb problem - 32 DIR 109 My 340 is fitted with a Weber 32 DIR 109 carb. When it is started I use full choke and no accelerator as per the manuals recommendations. As soon as the engine starts, and if the accelerator is untouced by me, the revs drop and the engine typically stops. I can usually get round this by pumping on the accelerator when I start the car, and once started the car runs quite smoothly. Before I strip the carb to investigate float levels etc, I wondered if anyone from this forum has experienced anything similar, and if so what you found the fault was. Regards to all Dave D24Tdavew

Dec 15th, 2004, 23:39	#2
johnw Guest Location:	RE: 340 - Carb problem - 32 DIR 109 Mine does that One pump of the accelerator before you turn the key and it's happy but it needs the choke gradually reducing over the first 20 seconds or it chokes itself to death as it warms up and the mixture becomes too rich, and I fitted a new carb last year. I suspect its the settings, not a worn-out carb (as mine is new). Or it could be an air leak between the carb and the manifold... You aren't supposed to change the fast idle speed but it does sound like the fast idle isn't fast enough? Anyone else?

Dec 16th, 2004, 00:16	#3
D24Tdavew Junior Member Last Online: Aug 28th, 2007 22:15 Join Date: Dec 2002 Location: Stourbridge	RE: 340 - Carb problem - 32 DIR 109 Thanks for that John. I did increase the fast idle(still keeping it within spec) to try and overcome the problem, but to no avail. I am thinking in terms of the float height, or even a perforated float. It seems to point to a lack of fuel. I'll take off the carb in the next week or so and do some checks and if anything turns up I shall reply to the forum. Many thanks Regards Dave D24Tdavew

Dec 16th, 2004, 10:16	#4
5lab Guest Location:	RE: 340 - Carb problem - 32 DIR 109 http://www.volvo300mania.com/forum2/...0-360-f571.htm

Dec 31st, 2004, 21:29	#5
D24Tdavew Junior Member Last Online: Aug 28th, 2007 22:15 Join Date: Dec 2002 Location: Stourbridge	RE: 340 - Carb problem - 32 DIR 109 As a follow up to the query mentioned, I would confirm that the fault has been found. I obtained a Weber Refurb kit and replaced all main diaphragms and the needle valve etc, in fact all the parts typically in the kit. The diaphragm called the Starting Device Diaphragm had a small hole in it. This forms part of the pneumatic choke control, and opens the choke valve as soon as the car starts. The engine now starts as you would expect on every cold start. Many thanks for the comments made. Regards Dave D24Tdavew

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