Fuel rail

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DaveEFI
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Fuel rail

Post by DaveEFI »

The fuel rail on my SD1 EFI doesn't hold pressure. It drops back to zero immediately the pump stops. it has an after market pump and regulator - the regulator an expensive nor rising rate adjustable type. I take it a one a valve in one of them is either missing or faulty.
It runs just fine, though, but takes a bit longer to start. Does anyone make external ones I could fit to the fuel rail?


Dave
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Rover SD1 VDP EFI
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ChrisJC
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Re: Fuel rail

Post by ChrisJC »

Are you sure it's not a leaky injector, or 9th (cold start) injector?

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stevieturbo
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Re: Fuel rail

Post by stevieturbo »

DaveEFI wrote:
Fri Jul 24, 2020 8:32 am
The fuel rail on my SD1 EFI doesn't hold pressure. It drops back to zero immediately the pump stops. it has an after market pump and regulator - the regulator an expensive nor rising rate adjustable type. I take it a one a valve in one of them is either missing or faulty.
It runs just fine, though, but takes a bit longer to start. Does anyone make external ones I could fit to the fuel rail?

You need to establish which isnt holding first. But I never had a problem starting with a setup that lost pressure. Although a setup that does hold may start a small fraction quicker.

What pump and reg is it ?
9.85 @ 144.75mph
202mph standing mile
http://www.youtube.com/watch?v=XgWRCDtiTQ0

DaveEFI
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Re: Fuel rail

Post by DaveEFI »

The pump is an unbranded substitute for the original Bosch - a direct replacement, and has given good service. The reg is a Malpassi adjustable but non rising rate.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y

stevieturbo
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Re: Fuel rail

Post by stevieturbo »

And does the Bosch have the non return valve fitting on it's discharge ?

Or what type of fitting is it ? The likes of 044's are an M12 thread, but they come with an adapter with a NRV in it, although any time I use them I remove it as it restricts flow a little.

Not sure if the pumps with say a barb hose tail on them would have a NRV inside....probably not.
9.85 @ 144.75mph
202mph standing mile
http://www.youtube.com/watch?v=XgWRCDtiTQ0

stevieturbo
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Re: Fuel rail

Post by stevieturbo »

9.85 @ 144.75mph
202mph standing mile
http://www.youtube.com/watch?v=XgWRCDtiTQ0

GDCobra
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Re: Fuel rail

Post by GDCobra »

I have a similar setup and it behaves the same, always thought it was odd but doesn’t give any issues so not bothered to investigate further. I had to remove the Bosch pump a few years ago as it failed, don’t know if that behaved any different as I never measured the pressure with that pump, fitted a Sytec at that point. Don’t know if there is a separate one way valve in the standard system or if that is in the pump

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