Turboman
Mab An Gov
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Sometimes a tap on the pump used to get it ticking again. But sometimes not.
Series 3 Weber 32/34 DTML on 2.25 petrol vapour lock woes
- Thread starter olriley
- Start date
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Back to the plot. Did the clear line drain before you put the electric pump in place?
Does the line only drain when the engine is hot?
If you have an electric pump then it should refill the line and the carb in a few seconds. Does it come on with the ignition?
Does the line only drain when the engine is hot?
If you have an electric pump then it should refill the line and the carb in a few seconds. Does it come on with the ignition?
Hicap phill
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Swirl pot…
Fitted as standard to the 2.5 petrol engines with these carbs.
Just make sure you have this connect the correct way.
vapour lock. If it stops the engine have you tried to restart with foot flat to the floor in the acelartor? Now this sounds mad but if there is no fuel it won’t flood the engine but could allow the fuel bowl to purge any vapour.
have you still got a standard fan on engine?
Is this a 2.5 or 2 .25?
(Still think this may be electrical)
Fitted as standard to the 2.5 petrol engines with these carbs.
Just make sure you have this connect the correct way.
vapour lock. If it stops the engine have you tried to restart with foot flat to the floor in the acelartor? Now this sounds mad but if there is no fuel it won’t flood the engine but could allow the fuel bowl to purge any vapour.
have you still got a standard fan on engine?
Is this a 2.5 or 2 .25?
(Still think this may be electrical)
Turboman
Mab An Gov
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Thread title says it is a 2.25. Which didn't have swirl pots, which I think are a waste of space anyway.
Foot down to the floor is a good idea, though. Not only puts in a lot of fuel, but also increases the air.
Did 2.5 petrols have Weber carbs as standard?
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Didn't know the series 3 ever had a 2.5 petrol. Every day's a school day!!
Turboman
Mab An Gov
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It didn't.
But the 2.5 petrols and 2.5 NA were a common retrofit in Series, they originally came from Nineties, One Tens, and, in the case of the diesels, from Taxis, Sherpa vans, etc.
2.5 petrol aren't that common in the UK, in fact, I think it is 20 years since I even saw one.
Hicap phill
Well-Known Member
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The 2.5 did have Webers as standard.
These also had swirl pots as standard(fitted to prevent vapour lock)fitted in same place as @olriley
Re looked at the photos & it’s a 2.25.
the 2.5 had a very large viscous fan unsure if this was to cool the engine or the engine bay as it got hot.
(well I had this engine in place while the TDI was been sourced as it uses all same mounts)
Turboman
Mab An Gov
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There are photos?The 2.5 did have Webers as standard.
These also had swirl pots as standard(fitted to prevent vapour lock)fitted in same place as @olriley
Re looked at the photos & it’s a 2.25.
the 2.5 had a very large viscous fan unsure if this was to cool the engine or the engine bay as it got hot.
(well I had this engine in place while the TDI was been sourced as it uses all same mounts)
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Any better pics of the carb? There seems an awful lot of pipes. What the blue one for that goes to a tee?
Turboman
Mab An Gov
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Now looked at the pics. 2286cc petrol with the carb of a 2.5 petrol.
As you say, a lot more pipes than I would like to see.
I think the best option would be to replace with the right carb, which, as Col suggests, is probably a Zenith, which I think are made again.
As a matter of general interest, our Series, which has the Solex carb, never starts straight away. It catches, runs for a few beats, then stops.
It starts again after a few spins over, no problems, hot or cold.
I don't think this is due to vapour locking, which I have never experienced as far as I can remember.
I think it is because the fuel in the float bowl simply evaporates while the vehicle is standing, only leaving a bit of fuel in the passages at the top of the carb, which is enough to run it for a few seconds. A few more cranks, and the lift pump has filled the bowl, and off it goes.
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Turboman
Mab An Gov
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Probably. It might have a few bits missing. You can get rebuild kits, or if it is very worn, there is a company that you can send them off to get a more professional job. They bore out the alloy bearings if they are worn, and press in little brass bushes where the rods turn in the body.
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It won't have any bits missing, it's how i took it off.
Likely worn though!!
Turboman
Mab An Gov
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I wondered about the link rod on the left, whether it should have a fitting on the top end. Maybe it does, but it is on the carb body.
It might be worn, but they are surprisingly tough, the alloy quality seems to be very good.
Couple of tins of carb cleaner, it might be good to go.
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The link that attached to the butterfly is in use in the SU, the sticky up bit of pipe is there vacuum pipe to the dizzy
ExMil109
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This 32/34 DMTL has a reputation for heat soak when used on the Landy engine - I think it was designed for crossflow engines where the inlet and exhaust manifolds are on opposite sides of the block.
There are two potential issues: vapour lock and flooding. Tthe swirl pot and electric pump are intended to prevent vapour lock and the vent solenoid is supposed to allow the float chamber to breathe when the engine is turned off, to prevent fuel in the float chamber overflowing into the manifold from heat soak. Either of these issues could be your problem...
My suggestion would be to reduce the heat into the carb as much as possible - heat shields, more airflow around the carb (some Fiats had a carb cooling fan), see if the intake air can be routed from a cooler place.
Good luck!
There are two potential issues: vapour lock and flooding. Tthe swirl pot and electric pump are intended to prevent vapour lock and the vent solenoid is supposed to allow the float chamber to breathe when the engine is turned off, to prevent fuel in the float chamber overflowing into the manifold from heat soak. Either of these issues could be your problem...
My suggestion would be to reduce the heat into the carb as much as possible - heat shields, more airflow around the carb (some Fiats had a carb cooling fan), see if the intake air can be routed from a cooler place.
Good luck!
olriley
Member
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- East Herts
Huge thanks for this.
I haven’t checked the solenoids, or done everything possible yet to reduce heat soak. Carb spacer was a start but heat shield would help too.
olriley
Member
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Thanks to all contributors so far. Your support much appreciated! I will crack this!
thinking aloud, 8mm fuel line to the carb might help too, as there’d be a greater volume of fuel to heat. It’s currently 6mm.
thinking aloud, 8mm fuel line to the carb might help too, as there’d be a greater volume of fuel to heat. It’s currently 6mm.
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i might be wrong, but isn't it the fuel already in the carb thats potentially the issue? with the float up and closing the inlet, no more fuel will come in to the carb
ciderman
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hi, on my small fleet of vehicles i have the similar problem. It is solved by moving the electric pump down to the chassis rail- so it works as a petrol pump rather than sucker.
In some cases the electric pump is fitted before the mechanical one and in series with it. This gives you the option of using it as a priming pump and switching off when engine is running.
it is a bugger to start it when unauthorised people are trying to remove your vehicle.
In some cases the electric pump is fitted before the mechanical one and in series with it. This gives you the option of using it as a priming pump and switching off when engine is running.
it is a bugger to start it when unauthorised people are trying to remove your vehicle.
