Serlock

OK, My car started to not work on petrol ( i have LPG Installed ). When igntion on - i do not hear that sound of pump. So i took it out. Wanted to test it with a battery - and the strange thing - it works. But when connected back to its original place - i dont hear it when ingition is turned on. Fuses in the passenger side are OK. What else i can test ? Of course.. a relay under passengers floor mat, what else ?Thanks in advance!

silverd2

A normal working pump will only run for about 2 seconds ONLY the FIRST time ignition key is switched on, to prime the system.

After that the pump will only run while the engine is turning, including during starter operation.

The engine speed sensor (crank position sensor) sends a signal to the ECM to energize the fuel pump relay. If the sensor is bad or disconnected, the fuel pump relay will not send power to the pump.

Serlock

Car run perfect on LPG, so crank sensor is ok .

silverd2

If you say so...I (and most) haven't a clue how the LPG conversion is plumbed or controlled, compared to the factory petrol system.

If all is well, voltage will be reaching the pump during cranking...not with key just turned to "ignition", unless engine is turning. If no voltage at the pump during cranking, you work your back...wiring, relay, ECM, engine speed sensor, ignition switch...not much more in the system would interrupt power to the pump.

Serlock

I took out the pump, went to a garage, guys tested it. IT is OK. Now i put it back, removed pipe from fuel line in the engine. I put that pipe into bottle, and tried to crank, fuel goes to the bottle. I put it back. Crank engine, cant start it, was cranking for a long time. But no success. Engine starts to catch up little but not start... So fuel pump is ok. any ideas?

silverd2

With pump out, was a delivery volume check done? ...It could pump, but insufficiently.

Did you add extra fuel after replacing the pump, to prime it? ...the first fuel put in goes right to the pump, not the bottom of the tank.

VagCom scan for codes?

Sure you're getting spark?

Fuel pressure check (per Bentley manual) under the hood...before and after the pressure regulator?

Serlock

Fuel pump check was bad. It was running but not goo enough. Changed pump and its fine now.

ALL i can say, that fuel pump change is easy, just follow youtube videos and anyone who is able to hold a spanner will do it.