Starting problem.

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Keith Clements
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Starting problem.

Post by Keith Clements »

My Javelin starting problem now seems to be cured it seemed an odd fault.
I could turn the engine over and over with no response with the starter motor. It had good spark and timing correct good compression. Fuel was getting through to the carbs. If i poured fuel down the carbs the engine would fire and run ok .It seemed to be happening only when cold with full choke.
Checked the pump output pressure with a pipe and reached 30 inches of head left for a while to check if any leak back through valves all ok.
As a last resort reconditioned the pump with a new kit now the car is firing first time.
Any ideas how the pump can cause this fault.
I have the carb manual and it states the starting fuel comes from a small hole in the bowl which comes out below the main butterfly how could the pump stop this flow.
Thanks Barry.

David Kemp » 03 Nov 2021 08:41 pm
In my daughters car , her pump , pumped, however as the diaphragm was old she replaced it.
The new pump diaphragm pumped 10 times better. Result better starting. The carb was now getting fuel instantly.

Nick Webster » 04 Nov 2021 07:31 pm
It occurs to me that if the pump is weak the flow from it will be stopped by the needle valve sooner than if it is a strong flow. This will be even if you think you have set the float level correctly. When starting from this state the standing level in the capacity tube will be lower and hence the flow from the jets will be very slightly less. I say very slightly because I struggle to believe that a couple of mm will make a difference, but it is the only explanation I have.

Nick
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Barry20383
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Re: Starting problem.

Post by Barry20383 »

Thanks for the info overhauling the pump has definitely cured the starting problem. The car is now starting from cold first time with full choke.
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Tony Fearn
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Re: Starting problem.

Post by Tony Fearn »

Barry20383 wrote: ↑Wed Nov 10, 2021 6:18 pm ...overhauling the (petrol)pump has definitely cured the starting problem...
Hi Barry,
Could you please let us know where you sourced the overhaul kit?
Thanks,
Tony.
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Keith Clements
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Your interest in the forum: Jup NKD 258, the most widely travelled , raced and rallied Jowett.
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Contact Keith Clements

Re: Starting problem.

Post by Keith Clements »

JCS I think based on other thread on JT.
viewtopic.php?p=45888#p45888
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