Hello guys , i have issue in my volvo s 80 1999 2.4L , my fuel pump doesn't turn on. I jumped positive(+) wire directly from the battery and i checked the pump is working and the engine starts. I looked for a PEM and FPS but i don't find these in my car. My fuses are good. And i checked all relays using a 12v battery everything works fine. But still i struggling to find exactly what is the problem. Guys please help me ... Now i kept a switch near steering wheel and i turn on while driving.....

 

Don't think your car as a fuel pressure sensor - just a regulator which (if like the 850) hides under the intake manifold. Do you get voltage to the fuel pump relay when you turn the key? There's 4 spades on the relay - one pair (smaller blades) are to actuate the relay, the larger pair are to send the current to the fuel pump. See what you have there. Also look and see if your car has an injector relay - again like the 850s where it is up on front over the radiator (gray box). Does anything happen when you wiggle the ignition switch while trying to crank over the engine?

 

PEM should be located under car, on top of your tank.

 

Hi guys,

My car S80 2007, engine doesn’t start as no fuel reach engine!!

Problem happened one month ago, I changed the fuel pressure sensor and fuel pump.

Again, same problem happened 4 days ago (3 weeks after replacing the fuel pressure sensor and Fuel Pump).

I noticed that, no signal comes to the fuel pump and once the engine starts the car is running perfect!!

Finding; when I press the brake pad and push start bottom, no electrical signal come to the fuel pump!!

Action I did:

- I removed the fuel tank and check the fuel pump separately it’s ok! And wire all is OK!!

- I passed the pump electronic module through a hole under the back seat and kept the module under the seat for easy access if it needs to change.

- Car starts immediately with no problem and runs perfectly even the acceleration is ok (why not the problem was engine start only)

- I put into the tank “Fuel system cleaner fluid” to clean injectors and remove any clogs.

Conclusion;

1- When I press the brake pad, no electrical signal is delivered, or

2- On starting the car PEM sometimes delivers signal to Pump and sometimes doesn’t deliver signal to pump.

Question:

1- Am I need to replace the PEM or

2- Is the problem with the wire coming from the brake to PEM or

3- Another mechanical issue?

I appreciate your valuable input guys 😊