Injection Fuel Pressure

[Guest daveg]

All

 

Does anyone know what pressures I can expect if I try and measure fuel pressure?

 

RS Components have a sensor that I might buy, there are two choices either 0-4 bar or 0-10 bar. Obviously the 0-4 would be more accurate but only if the pressure doesn't exceed 4 bar (about 60 psi)

 

Dave

PS Its my Red Top thats sick :boohoo:

[Big Jim]

The (Haynes) Vauxhall manual says "2.5 bar (36 lb/in²)"

 

Fuel pump delivery; 1.4 to 1.8 pints/minute

 

 

 

hope that helps.

[Guest daveg]

Jim

 

Thanks...that means a 4 bar gauge would do

 

Dave

[Guest chris brown]

Pinto also 2.5 bar

[Guest Ant]

The Bosch fuel pumps are only rated to 4 or 5 bar absolute pressure at maximum (3 or 4 bar gauge). The 0 to 4 will be fine. Not sure why you'd want one though. The fuel pressure is regulated to be slightly higher than manifold pressure, ie a little over 1 bar at most. Why not fit a vacuum gauge? I've got one and it's fab

 

Except I've sold it ... Hmm!

 

Ant

[Guest chris brown]

Except I've sold it

Was it fitted to the car at the time??

[Guest daveg]

Ant

 

I have a fault that is hard to trace...so I am thinking of using a scope to measure waveforms and pressure etc...

 

I also want to measure current going to injectors and spark plugs in a non invasive manor so maybe I will make up a ferrite ring with a coil winding...

 

Its all fun...but its stopping me working on the 2b :boohoo:

 

Dave

[Guest timswait]

I think Dave's trying to measure fuel rail pressure not manifold pressure, so a vacuum gauge isn't any use. I have a CD which garages use for looking up all kinds of technical data, so if you want exact values I can look them up.

Is it carbs or fuel injection? I think from memory that the fuel rail pressure should be 2.5 bar at low load raising to 3.5 bar at maximum load for the Pinto EFi. This is controlled by the pressure regulator, with the vacuum pipe connected it should be 2.5, with it disconnected 3.5. I'm not sure how this applies to a Vauxhall, if it's carbs it should be much lower than this. Either way the 0-4 bar gauge should be fine.

[Guest timswait]

Can you not use the diagnostic connector, surely it's easier then trying to trace waveforms etc?

[Dave R]

do you mind if you have a current output or a voltage output from this sensor ?

 

may have one that you can have to less that rs prices!

its voltage and was ordered in error so is unused

will sort it out later to see what range it is but i am sure its in the right sort or range you need

[Dave R]

dave send me a pm with your address please