Fuel pressue gauge
Discussion
Happy christmas to you all!
My Wedge has had an early christmas present: a fuel pressure gauge.
I thought it might be a useful addition to the engine bay. A quick way
of checking that all is well on the fuel pressure side of things.
I've had a search but can find anything about this on the forum. I cant
believe that I'm the only one to fit such a gauge. All I can find is
regulator stuff
Question is where to fit it. My guess is between the regulator and the plenum?
Anybody got any ideas?
cheers
Dave
My Wedge has had an early christmas present: a fuel pressure gauge.
I thought it might be a useful addition to the engine bay. A quick way
of checking that all is well on the fuel pressure side of things.
I've had a search but can find anything about this on the forum. I cant
believe that I'm the only one to fit such a gauge. All I can find is
regulator stuff
Question is where to fit it. My guess is between the regulator and the plenum?
Anybody got any ideas?
cheers
Dave
I run an oil filled pressure gauge off the 9th injector feed for years not, Ive never used the 9th injector and with my current setup will never need to use it again, its a good place to put a pressure gauge if you want to use on with the standard regulator or if you have a FSE you can fit the extra gauge if you like...
Ill pop up a pic if you want ?
Cambelt
Ill pop up a pic if you want ?
Cambelt
My car has a pressure gauge in place of the cold start injector. The usual advise is to mount it using some sort of bracket rather than just leave it flapping around on the end of the rubber hose (like mine 
).
My first one died for no apparent reason, it could have been the high-frequency pressure pulses in the rail.
ETA: it's a fantastic aid to diagnosing injection system faults. If you prime the fuel rail then pull the pump relay, if you fire any of the injectors you'll see the rail pressure drop. If you don't see the drop, the injector's not firing... and if the rail won't hold pressure when you take the relay out (or turn ignition off ) then you have a leak, a dead pressure regulator or an injector stuck open.
).My first one died for no apparent reason, it could have been the high-frequency pressure pulses in the rail.
ETA: it's a fantastic aid to diagnosing injection system faults. If you prime the fuel rail then pull the pump relay, if you fire any of the injectors you'll see the rail pressure drop. If you don't see the drop, the injector's not firing... and if the rail won't hold pressure when you take the relay out (or turn ignition off ) then you have a leak, a dead pressure regulator or an injector stuck open.
Edited by Wedg1e on Friday 21st December 14:34
Gauge fitted this morning.
I pulled out the fuel pump relay and turned the engine over to reduce the fuel pressure.
Removed the pipe and cut it in half. Fitted the gauge using a couple of fuel pipe clips
from Halfords. It's resting on pipework which isn't ideal I know.
Gauge holding steady at 30psi. Nice and reassuring!
A cabin mounted gauge would be better I agree. I didn't realise you could get them.
Have a good christmas
Dave
I pulled out the fuel pump relay and turned the engine over to reduce the fuel pressure.
Removed the pipe and cut it in half. Fitted the gauge using a couple of fuel pipe clips
from Halfords. It's resting on pipework which isn't ideal I know.
Gauge holding steady at 30psi. Nice and reassuring!
A cabin mounted gauge would be better I agree. I didn't realise you could get them.
Have a good christmas
Dave
Gauge should vary with respect to the inlet manifold vacuum level.
If you are at idle with throttle closed the gauge should be at the minimum (or going downhill with the throttle closed and the exhaust popping), if on full-throttle the inlet manifold should be at normal atmospheric and the gauge should read higher, this should show action of the fuel regulator.
Engine stopped and the ignition on, with the air-meter flap open (i.e. fuel pump running) the gauge reading should be high as there should be no inlet manifold vacuum.
I use a standard oil pressure gauge with an oil pressure sender spliced into the 9th injector pipe, the gauge is in the cockpit.
Russ
If you are at idle with throttle closed the gauge should be at the minimum (or going downhill with the throttle closed and the exhaust popping), if on full-throttle the inlet manifold should be at normal atmospheric and the gauge should read higher, this should show action of the fuel regulator.
Engine stopped and the ignition on, with the air-meter flap open (i.e. fuel pump running) the gauge reading should be high as there should be no inlet manifold vacuum.
I use a standard oil pressure gauge with an oil pressure sender spliced into the 9th injector pipe, the gauge is in the cockpit.
Russ
not an good idea to fit a "mechanical" fuel pressure manometer permanently:
the supliers of fuel regulators (like filterking or malpassi) always recommend to use the gauge only for setting the pressure and remove it afterwards. (and those regulators are fitted on low pressure systems...not injected cars with high pressure fuel system...so thats even more risky)
"The competition filter king from Malpassi is a very popular unit for carburettor equipped cars as it both regulates fuel pressure and filters fuel without restriction. Pressure is is adjusted via a screw on top of the unit and the range is 1.5 - 5 Psi. The pressure can be set accurately as this filter king model comes equipped with a fuel pressure gauge. It is advisable that once the desired fuel pressure is set, the gauge is removed and replaced with the blanking plug supplied."
the gauge can burst or fail--> fuel will spray around the enginebay
due to fitting the gauge by cutting a pipe/hose further junctions are created which my fail/leak --> fuel will spray around the enginebay
fibreglass burns well!!!
the supliers of fuel regulators (like filterking or malpassi) always recommend to use the gauge only for setting the pressure and remove it afterwards. (and those regulators are fitted on low pressure systems...not injected cars with high pressure fuel system...so thats even more risky)
"The competition filter king from Malpassi is a very popular unit for carburettor equipped cars as it both regulates fuel pressure and filters fuel without restriction. Pressure is is adjusted via a screw on top of the unit and the range is 1.5 - 5 Psi. The pressure can be set accurately as this filter king model comes equipped with a fuel pressure gauge. It is advisable that once the desired fuel pressure is set, the gauge is removed and replaced with the blanking plug supplied."
the gauge can burst or fail--> fuel will spray around the enginebay
due to fitting the gauge by cutting a pipe/hose further junctions are created which my fail/leak --> fuel will spray around the enginebay
fibreglass burns well!!!
Edited by GinG15 on Sunday 23 December 07:15
I'm wondering why you'd want a fuel pressure gauge anyway. Surely you'd know if fuel pressure was low - the car wouldn't drive very well, or not at all - and it wouldn't get too high. For me, it would just be something else to keep watching and worrying about.
I can see the point in using one to set up or check a fuel pressure regulator, but after that, it would be like having a gauge on the dash to tell me the steering wheel is still attached!
I can see the point in using one to set up or check a fuel pressure regulator, but after that, it would be like having a gauge on the dash to tell me the steering wheel is still attached!
GinG15 said:
not an good idea to fit a "mechanical" fuel pressure manometer permanently:
Didn't stop Lotus and many others from fittng capillary-fed oil pressure gauges in the cockpit with several feet of small-bore pipe bringing nice black hot oil into the cockpit (just above the driver's groin)... similar 'health and safty' risks involved. If I thought my fuel hoses were that ropey I'd change them.Fuel 'spraying around the engine bay' is less likely to ignite than brake fluid spraying around the engine bay...
Wedg1e said:
Didn't stop Lotus and many others from fittng capillary-fed oil pressure gauges in the cockpit
When I got my first (old) car I added a cheap direct oil gauge. I guess it was the cheapest 'hot rod' part I could fund, otherwise I have no idea why I was worried about the oil as it ran like the tank it was. Connected with a white plastic tube which promptly split and sprayed hot oil over my new jeans, new mats, and soon to be ex-girlfriend. I'll never do that again.Sorry guys but this all sounds a bit bizzare to me, Maybe im missing something but there should be NO fuel lines inside the cockpit of any car!..The thought of being sprayed with fuel whilst being trapped inside the car due to a bad accident is not worth thinking about..Even engine bay mounted gauges pose a risk from vibrating loose and spraying fuel everywhere..It may not ignite very quickly but the gasses will build up and then when ignition does happen..
Are electronic fuel pressure gauges any better?...Besides you can only view it on idle anyway..Having a fuel pressure gauge inside the car just sounds completely wrong..The word PRESSURE is very off putting..Please make sure you are being safe and sensible..I for one dont wish to read that a fellow wedger or anyone for that matter has been severely burnt or even killed due to a part fitted to their car that was not needed..As said if you have a problem with fuel pressure then you will know, Then you can test the pressure with a gauge..Im sure these gauges fail over time from periods of minimal use..Are they meant to be subject to pressure all of the time???....Please be safe!..Ziga
Are electronic fuel pressure gauges any better?...Besides you can only view it on idle anyway..Having a fuel pressure gauge inside the car just sounds completely wrong..The word PRESSURE is very off putting..Please make sure you are being safe and sensible..I for one dont wish to read that a fellow wedger or anyone for that matter has been severely burnt or even killed due to a part fitted to their car that was not needed..As said if you have a problem with fuel pressure then you will know, Then you can test the pressure with a gauge..Im sure these gauges fail over time from periods of minimal use..Are they meant to be subject to pressure all of the time???....Please be safe!..Ziga
Likewise I have had one fitted for over 2 years in the engine bay on my rising rate regulator. Its a helpful tool to make sure all is well on the fuel side of things. Thing to remember is to get one of the proper stainless and glass ones as the cheaper plastic face ones have been known to leak after a while.
I put my car in for a diagnostic check and hub dyno run once a year and again this is helpful in checking the health of the engine / comparison from the proceeding years telemetry and setting things up imho
Chris
I put my car in for a diagnostic check and hub dyno run once a year and again this is helpful in checking the health of the engine / comparison from the proceeding years telemetry and setting things up imho
Chris
zig,
You are missing something.
Electronic fuel pressure gauges do not have fuel running inside the cockpit as they have an isolator:
http://www.egauges.com/pdf/AutoMeter/783h.pdf
Fuel is kept in the engine bay.
Autometer offer both low and high pressure systems.
I like gauges:-)
Phil
420 SEAC
You are missing something.
Electronic fuel pressure gauges do not have fuel running inside the cockpit as they have an isolator:
http://www.egauges.com/pdf/AutoMeter/783h.pdf
Fuel is kept in the engine bay.
Autometer offer both low and high pressure systems.
I like gauges:-)
Phil
420 SEAC
One of these are also in the new 2012 SEAC 7-Gauge dash panel: http://www.youtube.com/watch?v=4c2dOkh04GY
Phil
420 SEAC
Phil
420 SEAC
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