Fuel pressure test

[Giniw]

Hello Everyone,

I had the chance to get the official fuel injection diagnostic kit, so I would like to check my fuel pump.

The fuel pressure gauge is plugged to the injection ramp port (no problem for that) and the return line to the reservoir is supposed to be unplugged from the ramp/regulator and plugged into the pressure gauge (and a cap put on the fuel regulator instead of the fuel return line).
So the fuel gauge is basically plugged as a bypass.

It seems very easy on the paper but I am a bit worried about unplugging the fuel return line from the regulator as the fuel line is quite stiff and it looks like it's not really designed to be unplugged without being damaged/replaced? Is a fuel line damaged when it's unplugged?

Thanks in advance!

[Vulcan Grey]

It is definitely possible to unplug the return line from the regulator and move it around a bit.

You definitely want to depressurize the system first (don't forget to remove the filler caps too.

And you'll need a plug to plug the return from the regulator. 

You'll also need to follow the instructions in the EMH manual, or else you risk damaging something by overpressurizing the fuel system.

[Giniw]

Yes no problem: I had depressurized it before I checked whether the injectors or regulator or fuel pump were leaking or not (something did when cold, but apparently all is fine when the engine is warm).

I just didn't dare to pull the return line.

 

17 minutes ago, Vulcan Grey said:

don't forget to remove the filler caps too.

I have let them closed, why would they need to be opened? As far as I remember it's not written to open them anyway?

17 minutes ago, Vulcan Grey said:

And you'll need a plug

I have the original rubber plug too ^^ (at least I think I do: it probably fell from the box when I opened the parcel since I found a rubber cap on my office floor at the same period and it had nothing to do here, while it's so similar to the picture found in the workshop manual)

[Giniw]

Here it is (it remained on my desk for a few month before I figured out what it probably was last week ) :

[Vulcan Grey]

3 hours ago, Giniw said:

I have let them closed, why would they need to be opened? As far as I remember it's not written to open them anyway?

 

IF you depressurize the system, but leave the fuel caps on, then small changes in atmospheric pressure can cause fuel to come streaming out of the fuel lines!  Happened to me. Taking the fuel filler caps off, equalizes the pressure on both sides of the fuel lines.

[Giniw]

Thanks I wouldn't have thought to that!