V70 Base- Power Lag Under 2k Rpms and Now Won't Start

[chrism]

Times like this a fuel pressure gauge can be very handy. Doesn't have to be anything fancy.

https://www.amazon.com/Excelvan-100PSI- ... sure+guage

[alexv702003]

So you think the pem is the problem? What is it?

I checked fuel pressure with a gauge and there is nothing.

[alexv702003]

I checked power to fuel pump with a multimeter and it was a little over 10 volts. Seems like my fuel pump is dead. Only 1 year old Bosch.

[abscate]

Shouldn't the pump hbe at battery voltage?? 10 is really low

[chrism]

I have a dumb question - how does the Fuel Pressure Sensor (FPS) tell the pump to control the pressure? Does it vary the current to the pump or vary the voltage? I'm wondering if the FPS is the culprit. They are so notoriously fault-prone that, years ago, Volvo issued a bulletin on them to provide one free replacement per VIN (for certain VIN's).

[alexv702003]

How can I test the FPS?

[abscate]

The pump module modulates the voltage to the pump to control fuel pressure, so you need an oscope to look at the waveform

On my 2005, pin 4 should carry the battery voltage per attached

[oragex]

Failing FPS will usually cause hesitation/sputtering during acceleration. On metal gas tank cars, the PEM must be checked in the first place. Often times a good fuel pump is replaced because of a faulty PEM.

[chrism]

The pump module modulates the voltage to the pump to control fuel pressure, so you need an oscope to look at the waveform.

So a reading of 10V at the pump may be a GOOD sign - showing that the FPS is doing its job???

[abscate]

It's not definitively good or bad

Pin 4 at the PEM should be battery voltage though