Fuel vapourisation?

With the temperature hovering around the 30 degree C mark I'm getting problems restarting when the engine is hot. It's fine starting from cold. Is this fuel vapourisation? If so, how do you solve it?

The car is a carb. 02 with the Solex twin barrel... see last month's Car of the Month.

Hello John

We had a problem like this the other week when it was very hot. We realised shortly after that we had not switched the summer/winter box over so we were drawing in the hottest air we possibly could and once switched over it was fine again.

All the best

Fay

*******************************************************************
Jaymic Ltd, 2002 Thurgarton Road, Aldborough, Norfolk, NR11 7NY
Tel: +44 (0)1263 768768 Fax: +44 (0)1263 768336
www.jaymic.com Email: (Address removed)
*******************************************************************

----- Original Message -----
From: John Paulding
To: BMW '02 Owners
Sent: Wednesday, July 01, 2009 5:14 PM
Subject: [bmw02] Fuel vapourisation?

With the temperature hovering around the 30 degree C mark I'm getting problems restarting when the engine is hot. It's fine starting from cold. Is this fuel vapourisation? If so, how do you solve it?
The car is a carb. 02 with the Solex twin barrel... see last month's Car of the Month.
www.jigluhood.com – communities that think for themselves

A logical thought, but it's not that. The lever is locked in the summer position. I don't know how good the diverter box is inside though. I'll try taking the hot pipe off and blanking the inlet on the box in case hot air is leaking past the diverter.

If I crank the engine for a while and then blip the throttle it starts, which suggests there's no fuel in the float chamber. Does that giveanybody any ideas?

I've checked for leaks and ruled that out.

JP

It might be flooding, ie needle valve and seat are worn.
After a run, lift off the air filter cover and see if you can see neat fuel dripping onto the throttle plate, or open the throttle by hand and look into the bottom of the manifold and see if there is any puddles of fuel.

Date: Thu, 2 Jul 2009 17:55:52 +0100
From: (Address removed)
To: (Address removed)
Subject: Re: [bmw02] Fuel vapourisation?

A logical thought, but it's not that. The lever is locked in the summer position. I don't know how good the diverter box is inside though. I'll try taking the hot pipe off and blanking the inlet on the box in case hot air is leaking past the diverter.
If I crank the engine for a while and then blip the throttle it starts, which suggests there's no fuel in the float chamber. Does that giveanybody any ideas?
I've checked for leaks and ruled that out.
JP

www.jigluhood.com – communities that think for themselves

Find someone to snuggle up with Brrr... its getting cold out there

Yes, of course!

Same symptoms but totally opposite cause. I'll check it out.

Regards JP

On 2 Jul 2009, at 18:51, John Hudson wrote:

It might be flooding, ie needle valve and seat are worn.
After a run, lift off the air filter cover and see if you can see neat fuel dripping onto the throttle plate, or open the throttle by hand and look into the bottom of the manifold and see if there is any puddles of fuel.

Date: Thu, 2 Jul 2009 17:55:52 +0100
From: (Address removed)
To: (Address removed)
Subject: Re: [bmw02] Fuel vapourisation?

A logical thought, but it's not that. The lever is locked in the summer position. I don't know how good the diverter box is inside though. I'll try taking the hot pipe off and blanking the inlet on the box in case hot air is leaking past the diverter.
If I crank the engine for a while and then blip the throttle it starts, which suggests there's no fuel in the float chamber. Does that giveanybody any ideas?
I've checked for leaks and ruled that out.
JP
www.jigluhood.com – communities that think for themselves

Find someone to snuggle up with Brrr... its getting cold out there
www.jigluhood.com – communities that think for themselves

Hi John

How heavy is the electrical consumption on your car?

Things like an electric fan and other gizmos can starve the spark plugs and starter of leccy when you do a hot start (happens all the time with mine, keep meaning to build in an override switch for the Kenlowe) as theres not quite enough current to run the fan and turn over the engine plus firing the sparks.

Its much the same job as yours to start it, a few extra cranks and then flooring it seems to work okay - plus it shouldn't be the carb as I've just replaced it with a fully reconditioned one (although I'm still messing with the mixture settings and have a few lumpy spots around certain rev ranges). Could just be that my alternator is on its last legs of course, and Mike's always telling me that my starter doesn't sit exactly right so that may have a bearing. As may the electric fuel pump which I didn't fit and have no idea as the specification or age of (I'd go back to stock, but would need to change the cylinder head which a tii one) Ah, old cars eh!!

However I do have a vague recollection that you've upgraded your alternator to a higher capacity one so it may very well not be that at all.

Pete

*******************************************************************
Jaymic Ltd, 2002 Thurgarton Road, Aldborough, Norfolk, NR11 7NY
Tel: +44 (0)1263 768768 Fax: +44 (0)1263 768336
www.jaymic.com Email: (Address removed)
*******************************************************************

----- Original Message -----
From: JOHN PAULDING
To: (Address removed)
Sent: Thursday, July 02, 2009 7:09 PM
Subject: Re: [bmw02] Fuel vapourisation?

Yes, of course!

Same symptoms but totally opposite cause. I'll check it out.

Regards JP

On 2 Jul 2009, at 18:51, John Hudson wrote:

It might be flooding, ie needle valve and seat are worn.
After a run, lift off the air filter cover and see if you can see neat fuel dripping onto the throttle plate, or open the throttle by hand and look into the bottom of the manifold and see if there is any puddles of fuel.

Date: Thu, 2 Jul 2009 17:55:52 +0100
From: (Address removed)
To: (Address removed)
Subject: Re: [bmw02] Fuel vapourisation?

A logical thought, but it's not that. The lever is locked in the summer position. I don't know how good the diverter box is inside though. I'll try taking the hot pipe off and blanking the inlet on the box in case hot air is leaking past the diverter.
If I crank the engine for a while and then blip the throttle it starts, which suggests there's no fuel in the float chamber. Does that giveanybody any ideas?
I've checked for leaks and ruled that out.
JP
www.jigluhood.com – communities that think for themselves

Find someone to snuggle up with Brrr... its getting cold out there
www.jigluhood.com – communities that think for themselves

www.jigluhood.com – communities that think for themselves

Hi Pete

Thanks for the suggestions, but I don't think that's the problem. The car does have lots of gizmos, electric fan. air con., etc. but they shut off when the engine is cranking and the car has an 80 Amp alternator and a sealed battery wired up with welding cable so there's more than enough sparks....... and the engine starts fine from cold, so that suggests that current isn't the problem.

I think John's suggestion about flooding is the most likely. I haven't had time to check it out but I'll take a look over the weekend.

Thanks to all who have tried to help.

Regards JP

On 3 Jul 2009, at 09:04, Jaymic Ltd wrote:

Hi John

How heavy is the electrical consumption on your car?

Things like an electric fan and other gizmos can starve the spark plugs and starter of leccy when you do a hot start (happens all the time with mine, keep meaning to build in an override switch for the Kenlowe) as theres not quite enough current to run the fan and turn over the engine plus firing the sparks.

Its much the same job as yours to start it, a few extra cranks and then flooring it seems to work okay - plus it shouldn't be the carb as I've just replaced it with a fully reconditioned one (although I'm still messing with the mixture settings and have a few lumpy spots around certain rev ranges). Could just be that my alternator is on its last legs of course, and Mike's always telling me that my starter doesn't sit exactly right so that may have a bearing. As may the electric fuel pump which I didn't fit and have no idea as the specification or age of (I'd go back to stock, but would need to change the cylinder head which a tii one) Ah, old cars eh!!

However I do have a vague recollection that you've upgraded your alternator to a higher capacity one so it may very well not be that at all.

Pete
*******************************************************************
Jaymic Ltd, 2002 Thurgarton Road, Aldborough, Norfolk, NR11 7NY
Tel: +44 (0)1263 768768 Fax: +44 (0)1263 768336
www.jaymic.com Email: (Address removed)
*******************************************************************
----- Original Message -----
From: JOHN PAULDING
To: (Address removed)
Sent: Thursday, July 02, 2009 7:09 PM
Subject: Re: [bmw02] Fuel vapourisation?

Yes, of course!

Same symptoms but totally opposite cause. I'll check it out.

Regards JP

On 2 Jul 2009, at 18:51, John Hudson wrote:

It might be flooding, ie needle valve and seat are worn.
After a run, lift off the air filter cover and see if you can see neat fuel dripping onto the throttle plate, or open the throttle by hand and look into the bottom of the manifold and see if there is any puddles of fuel.

Date: Thu, 2 Jul 2009 17:55:52 +0100
From: (Address removed)
To: (Address removed)
Subject: Re: [bmw02] Fuel vapourisation?

A logical thought, but it's not that. The lever is locked in the summer position. I don't know how good the diverter box is inside though. I'll try taking the hot pipe off and blanking the inlet on the box in case hot air is leaking past the diverter.
If I crank the engine for a while and then blip the throttle it starts, which suggests there's no fuel in the float chamber. Does that giveanybody any ideas?
I've checked for leaks and ruled that out.
JP
www.jigluhood.com – communities that think for themselves

Find someone to snuggle up with Brrr... its getting cold out there
www.jigluhood.com – communities that think for themselves

www.jigluhood.com – communities that think for themselves
www.jigluhood.com – communities that think for themselves

Information in this message is confidential and may be legally privileged. It is intended solely for the person to whom it is addressed. If you are not the intended recipient, please notify the sender and please delete the message from your system immediately. The contents of an attachment to this e-mail may contain software viruses, which could damage your own computer system. While John Paulding Associates have taken every reasonable precaution to minimise this risk, we cannot accept liability for any damage, which you sustain as a result of software viruses. You should carry out your own virus checks before opening the attachment.

Any views or opinions presented or expressed are those of the author and may not necessarily represent those of John Paulding Associates, no representation is given nor liability accepted for the accuracy or completeness of any information contained in this email unless expressly stated to the contrary.