Fuel pressure regulator
Discussion
Can somebody please confirm (or not) if this is the correct fuel pressure regulator for a Chimaera avoiding the Tvr tax?
Thanks
http://www.island-4x4.co.uk/fuel-pressure-regulato...
Thanks
http://www.island-4x4.co.uk/fuel-pressure-regulato...
The fuel pressure regulator is calibrated to hold rail pressure at a constant 2.5 Bar which is 36psi.
Take your pressure reading at the Schrader valve on the rail with the vac pipe removed & blocked off, or better still just leave connected but clamp it.
The fuel pressure regulator is a very reliable unit and rarely fails, the wiring to the fuel pump on the other hand is poor and can mean the pump doesn't receive sufficient amps to operate at full power which in turn can mean lower than ideal fuel pressure.
A one way valve (check valve) is also a good idea as fuel can drain back through the pump leaving it momentarily dry after a long lay up causing extended cranking when you first start the car, the high pressure fuel pump must have fuel to pull against to work correctly.
Given the correct voltage & amps the external type Bosch high pressure fuel pumps as fitted to Chims & Griffs are very efficient, they are excellent at pushing fuel but are not particularly efficient at pulling it from the supply (tank).
Consequently many vehicles with this type of external high pressure fuel pump were also fitted with a second low pressure high volume lift pump (normally fitted inside the petrol tank), it's job being purely to get a good volume of fuel to the back of the high pressure pump so it can do it's job of pushing fuel at high pressure to the rail.
An example of this duel pump system can be found on the Porsche 928, amongst many others.
While not essential, adding a high volume low pressure lift pump at the tank pickup to supply the Bosch high pressure pump can help with cold starts after a long layup, the addition of a check valve between high pressure pump & the fuel filter may also be advantageous.
Take your pressure reading at the Schrader valve on the rail with the vac pipe removed & blocked off, or better still just leave connected but clamp it.
- Fit your fuel pressure gauge to Shrader valve on the fuel rail
- Turn the key to the on position
- Disengage the immobiliser
- Listen for the fuel pump buzz for 3-5 seconds
- Observe fuel pressure (34 PSI is fine)
- Start engine
- Observe fuel pressure (36 PSI is fine)
- If pressure is significantly lower or higher replace fuel pressure regulator
- Run and keep & eye on the gauge to ensure pressure is maintained
- If pressure rises or drops off replace fuel pressure regulator
- Turn engine off
- Observe fuel pressure is maintained (34 PSI is fine)
- If pressure drops off rapidly replace fuel pressure regulator (a one way valve may also help)
The fuel pressure regulator is a very reliable unit and rarely fails, the wiring to the fuel pump on the other hand is poor and can mean the pump doesn't receive sufficient amps to operate at full power which in turn can mean lower than ideal fuel pressure.
A one way valve (check valve) is also a good idea as fuel can drain back through the pump leaving it momentarily dry after a long lay up causing extended cranking when you first start the car, the high pressure fuel pump must have fuel to pull against to work correctly.
Given the correct voltage & amps the external type Bosch high pressure fuel pumps as fitted to Chims & Griffs are very efficient, they are excellent at pushing fuel but are not particularly efficient at pulling it from the supply (tank).
Consequently many vehicles with this type of external high pressure fuel pump were also fitted with a second low pressure high volume lift pump (normally fitted inside the petrol tank), it's job being purely to get a good volume of fuel to the back of the high pressure pump so it can do it's job of pushing fuel at high pressure to the rail.
An example of this duel pump system can be found on the Porsche 928, amongst many others.
While not essential, adding a high volume low pressure lift pump at the tank pickup to supply the Bosch high pressure pump can help with cold starts after a long layup, the addition of a check valve between high pressure pump & the fuel filter may also be advantageous.
I'm going to print that off and add it to my folder marked "Chimpo's bumper TVR service manual". Nice one Dave 
I don't have a pressure gauge to test 
but when I pull the vacuum pipe off the regulator it smells strongly of petrol. If I suck on the pipe and put my tongue over it, there is a light vacuum though. However once I've done that I then have to spit all the petrol smell out of my mouth as when I suck hard, it really tastes of petrol. No petrol has come out though, just very strong fumes/smell.
but when I pull the vacuum pipe off the regulator it smells strongly of petrol. If I suck on the pipe and put my tongue over it, there is a light vacuum though. However once I've done that I then have to spit all the petrol smell out of my mouth as when I suck hard, it really tastes of petrol. No petrol has come out though, just very strong fumes/smell. A900ss said:
I don't have a pressure gauge to test but when I pull the vacuum pipe off the regulator it smells strongly of petrol. If I suck on the pipe and put my tongue over it, there is a light vacuum though. However once I've done that I then have to spit all the petrol smell out of my mouth as when I suck hard, it really tastes of petrol. No petrol has come out though, just very strong fumes/smell.
That certainly sounds like fuel is leaking past the diaphragm, a replacement fuel pressure regulator is the answer. but when I pull the vacuum pipe off the regulator it smells strongly of petrol. If I suck on the pipe and put my tongue over it, there is a light vacuum though. However once I've done that I then have to spit all the petrol smell out of my mouth as when I suck hard, it really tastes of petrol. No petrol has come out though, just very strong fumes/smell. Google the Land Rover part number: ETC8494
I suspect you'll find three options:
- Original Land Rover new/old stock
- Bosch
- Alternative (BritPart)
Your other option is to fit an adjustable after market FPR, if you go this route just make sure you buy a quality one and avoid the rising rate type.
Personally I'd have a ring round a few Land Rover breakers and pay £20 for a good used original.
ChimpOnGas said:
A900ss said:
I don't have a pressure gauge to test but when I pull the vacuum pipe off the regulator it smells strongly of petrol. If I suck on the pipe and put my tongue over it, there is a light vacuum though. However once I've done that I then have to spit all the petrol smell out of my mouth as when I suck hard, it really tastes of petrol. No petrol has come out though, just very strong fumes/smell.
That certainly sounds like fuel is leaking past the diaphragm, a replacement fuel pressure regulator is the answer. but when I pull the vacuum pipe off the regulator it smells strongly of petrol. If I suck on the pipe and put my tongue over it, there is a light vacuum though. However once I've done that I then have to spit all the petrol smell out of my mouth as when I suck hard, it really tastes of petrol. No petrol has come out though, just very strong fumes/smell. Google the Land Rover part number: ETC8494
I suspect you'll find three options:
- Original Land Rover new/old stock
- Bosch
- Alternative (BritPart)
Your other option is to fit an adjustable after market FPR, if you go this route just make sure you buy a quality one and avoid the rising rate type.
Personally I'd have a ring round a few Land Rover breakers and pay £20 for a good used original.
ChimpOnGas said:
The fuel pressure regulator is calibrated to hold rail pressure at a constant 2.5 Bar which is 36psi.
Dont forget the fuel pressure will be a lot lower than 36 psi with the engine running at idle due to the inlet vacuum- from memory nearer 27psi. You have to disconnect the vacuum pipe to see 36 psi.- Start engine
- Observe fuel pressure (36 PSI is fine)
Just released the fuel pressure by pressing the Schrader valve in the fuel rail. No fuel come out
I guess this is another sign the regulator is dead as it isn't holding pressure.
When I got the old regulator off its not a Bosch one as it has different markings so I guess it has been replaced in the past with an inferior part. It does say 2.5 bar on it though so it's probably just a pattern part.
I guess this is another sign the regulator is dead as it isn't holding pressure.
When I got the old regulator off its not a Bosch one as it has different markings so I guess it has been replaced in the past with an inferior part. It does say 2.5 bar on it though so it's probably just a pattern part.
blitzracing said:
ChimpOnGas said:
The fuel pressure regulator is calibrated to hold rail pressure at a constant 2.5 Bar which is 36psi.
Dont forget the fuel pressure will be a lot lower than 36 psi with the engine running at idle due to the inlet vacuum- from memory nearer 27psi. You have to disconnect the vacuum pipe to see 36 psi.- Start engine
- Observe fuel pressure (36 PSI is fine)
ChimpOnGas said:
Take your pressure reading at the Schrader valve on the rail with the vac pipe removed & blocked off, or better still just leave connected but clamp it.
Quote taken from my original post 
Belle427 said:
You would tee into the feed line to the fuel rail but you would need the suitable test equipment for that.
I did read about maybe removing the fuel temp sender for a gauge but cant confirm if the hole is blind or not.
This ^ concerning the T bit I did read about maybe removing the fuel temp sender for a gauge but cant confirm if the hole is blind or not.
but sadly the fuel temp hole is blind Gassing Station | Chimaera | Top of Page | What's New | My Stuff