Fuel pressure problem, code P2291

Hello. My car has been running perfectly. Driving along at 30 mph the engine cut out.

RAC took my car home for me. He said that there was no fuel. It was dark, I had no tools and I had to stay back because of this virus.

There seemed to be no fuel in the filter. I changed the filter and still no fuel.

I dug out my Foxwell Code reading gadget. Code P2623. Fuel Regulator open. I took it off and it was stuck. Cleaned it up and it started to work, but a bit sticky. Put it back on. Car started. Car stopped. I think that it was faulty but not preventing the car from running.

I bought a new Fuel Regulator and put it on. Cleared the codes. Checked that the codes where clear. New code. P2291 Fuel pressure too low. Live data said very low.

Got out the old fuel pressure gauge and the fuel pressure isn't low.

So. Maybe a fuel sensor problem. I have the Haynes Manual. It give absolutely no information about the fuel electrical system. And I can't find anything useful on the internet.

I know that these sensors have a 5v supply, an earth and an output that varies with the fuel pressure. I don't have a wiring diagram.

So, I got out the old multi metre. And I found 5v on 2 of the wires. Something not right here?

The wires disappear and I can't follow them. I did manage to find the CPM. It seems to me that the 5v must come from there and the signal wire too. Not sure about the earth. But, I found all 3 of them.

It seems that I have 5v coming out of the two of the pins. Pin 6 and 25. I believe that 6 is the proper 5v. 25 shouldn't be 5v.

Look. If this was a good old mechanical engine I could sort this out in my sleep. I can sort of use the codes to point me in the direction of a fault. Brain Power!

But, I have no diagram. I have no information at all. I'm running on logic and I don't have enough to go on.

I have a feeling that my PCM has messed up. I can't be sure. I don't know why there's no information to work with.

Lastly, I checked the circuit to the injectors. I don't know why. The pressure is fine. So, why did I check this? Because I'm pulling my hair out and I've run out of ideas.

There is 5v to all of the injectors. Now, I thought that they were powered from the battery, into the injector and then to the PCM which turned it on for whatever time it thinks.

I might struggle to measure the voltage of a pulse. But I can measure the voltage coming down the wire to the injectors.

But, here's the thing. While I get 5v on all of the injectors, they are not all joined together. Not fed from a common source. 1 and 4 are joined. 2 and 3 are joined.

This makes sense and matches the firing order. It must also mean that the computer supplies the voltage too. And, if it's a pulse, 5v could be right. My metre can't measure a pulse. It more than likely give me an average.

I don't want to go around in silly circles. It's easy to start to wander from the facts when I am at a stand still.

I have an urge to try a new cam sensor. I refuse to start changing parts unless I have a reason. I like to find the fault and then fix it.

So, my car is on the 5v coming down both wires on the fuel pressure sensor and the P2291 code. The code is there for a reason. The pressure is not low. So, something is causing the false reading.

I need to know am I so out of date that I don't know anything any more? Should there really be 2 identical 5.28 volts on the 2 outside pins of the sensor?

Does it mean that my computer is broken?

Help!

Honestly, I can usually manage. But, this time, I'm stuck.

Oh, the live data says that the voltage from the sensor is 0.01v This seems to be very low to me. I can half understand this with 5v on the 2 wires.

I would be very grateful for any ideas that you might have.

Thank you.

Andrew.