mystery fuel pump problem vp 3.8L v6

[fullysickmick]

car stopped working thought problem was immobilizer so disconnected immobilizer system car was still not working and no fuel pump noise, so replaced fuel pump with new unit still no noise so checked fuel pump connection with test light and power was there thought there might be problem with fuel pump assembly, so connected to battery and fuel pump ran beautifully. Went to rear of vehicle again checked pump with test light once again power was there, connected fuel pump assembly and fuel pump once again not running. I have no idea what the problem is either does my brother he is across the state my brother thought it may be the body module after he suggested the other tests over the phone. Could any one possibly help me with this problem my brother is stumped and i am 17 and i cant afford to get an auto electrician

 

[Andrew426]

Check wiring connections. Could be corrosion on a connector, or a pin getting pushed out the back of the plug

 

[fullysickmick]

yer thanks for that my brother suggested that i should have put that down but still no joy

 

[bcw61]

I can't remember if the fuel pump is earthed through the tank mounting or has a seperate earth point, but a bad earth could possibly be causing the issue. You could run a temporary bypass earth wire to check for this.

Although you have already used a test lamp, you might also check that you have positive battery voltage at the fuel pump terminal when actually connected and supposed to be powered on, to eliminate the possibility of a high resistance in the positive line.

 

[illegal_____]

hi i had a simialr problem replace fuel pump still no luck car wouldnt start so went thru a **** load of tests with a mech mate over the phone the last option he gave me was to unscrew the fuel line going into the right had fuel rail unscrewd it turned ignition on fuel pissed out the line so did the line up the started car and it kicked over 1st go so it must of been airlock in the line

 

[fullysickmick]

ive tried bleeding the air from the system but the problem is the fuel pump dont even start up

 

[illegal_____]

have u swapped relays around? do u hear the realay clicking when u turn igniton on? have someone hold there finger on the realy as u kick it over?

 

[fullysickmick]

yer i have swapped relays they are all working fine anyway

 

[Jxfwsf]

check the oil pressure switch/connection, fuel pump power runs through that, may be getting a voltage reading but it may not be a good enough contact somewhere along the lines to actually run it another point to test with a multimeter is the purple wire on the aldl connector (won't have voltage when the engine isn't running but should when the engine is being cranked over or running), and it runs a separate earth as someone asked earlier, just behind the back seat in the boot area on the drivers side you see the wires going thru to the pump, maybe unwrap them and expose the negative wire and earth it to the body with a tech screw (make sure there's no fuel lines or other things on the other side that you could pierce) and see if that makes a difference.