Thread: Fuel pump pressure?

Doesn't quite make sense, but a fuel pressure gauge is an extremely handy tool

I don't know about the DII but on the late DI's thay have a shraider valve on the injector pipe that I use to take pressure readings from.
For the guage I used a cheap LCD tyre pressure gauge. It worked just fine & the display from the LCD display was very accurate when compared with the proper one at the workshop.

I also don't understand the 2nd part of your question.

sorry everyone,,

the actual pump in a D1 was a genuine Bosche pump.
was just wondering if the D2 was just another Bosche pump,,,


Then I could get all the info off the Bosche website--

Pedro, what D2 are you talking about GEMS or Thor.
Thor has a different and more expensive pump as it works on 3 bar pressure .

I do not know about GEMS.
But why do you want to know about fuel pressure? Its probably the least likely thing to cause problems as fuel pumps generally work or don't work.

I know the D1 rail has a schrader valve, and the Thor does also, so I presume the GEMS will also. I guess you know that on a D1 and I presume GEMS the pressure is compared to the inlet manifold pressure, ie you must disconnect the vacuum line if you are checking and expect 2.5 bar. The Motronic in Thor is absolute as the regulator is in the fuel tank and there is no return line ,ie there is no vacuum compensation.
By the way , a quick diagnostic with rovacom should show some sort of error message it there is a problem, even if it may say "high output of o2 sensors, or low output"
Regards Philip A

Thanks Phillip,,

those rovercoms are in short supply around here,,,

I was just thinking of testing the pressure,, and if there is a problem then it would be an intank blockage or pump malfunction,,
and THEN I'd rip the back out of the car ,,,

but if the pressure was good--
I'd go to coil packs.


make sense??

Originally Posted by Pedro_The_Swift

In a D2 V8,,

is a fuel pressure gauge a common workshop item?

Hi Pedro

Common question is "How do you test the fuel pressure" (which has everyone scratching their heads .. Me included)

In another pump thread problem ... I have been suggesting to get the pump to fill a 2ltr bottle with fuel & time it
DiscoDave did this in his thread & came up with 50 seconds .. His pump is shot

Another new Post is the one about the TD5 dying ... Fuel pump problem .. if only he could self test with basic tools

The theory would be .. Time it takes for 2litr's = Pressure // No idea if it is sound diagnostics .. untill you try it
If enough answers were given then maybe "a pattern would appear" to show whats good & whats bad ... Which would give a "basic self test"

Just a thought

and its a good thought!!

not sure what sort of numbers (quantity) we'd get though,,

I THINK the ratio of diesels to V8's is around 10 to one,,,

(another POLL perhaps?)

Originally Posted by Pedro_The_Swift

and its a good thought!!

not sure what sort of numbers (quantity) we'd get though,,

I THINK the ratio of diesels to V8's is around 10 to one,,,

(another POLL perhaps?)

I think you would have to set it up as the following:

Three Posts
1 for Diesel
I for petrol EFI
1 for petrol carby

Details required in post for accuracy

Time it took to fill ...
Pump status ( good or Bad )
Pump name / model ...
Car model .....
K's on clock .....
EFI or Carby or Diesel... (field detail required if set up in 1 thread only)


I don't think a patten would appear untill 10 good & 10 bad cars where recorded

Also ... The fuel line would have to be disconnected at the fuel rail at motor level... Need the resistance of the height ... Not at the gas tank level // no resistance there