fuel pump doesnt prime

[Matt_vp]

does the check engine light come on when u turn the ignition to on.

 

[Burnout_bro]

havnt checked why what would that mean

 

[Matt_vp]

i had a problem with my fuel pump not getting power and my check engine light wouldn't come on with the ignition turned to on. so if u check and its not coming on i can tell u how to get it to work, but im still unsure of what was causing it.
Matt

 

[Not_An_Abba_Fan]

Get hold of another ECU if you can and change that, see what happens.

 

[BrianH]

Are you getting power at the pump when the ignition is turned on? You will need a test light or a multimeter to check this and you may need someone to assist you because you will only have the power for two seconds unless the engine is cranking so it is no use turning the ignition on then walking down the back to check it.

If you have power but the pump will not work then check the pump earth. The wire colours I gave you yesterday came from the factory engine manual but I just noticed the wiring diagram manual gives more detail and shows more colours and connectors. The wiring harness going to the pump should end in a round white plastic push in terminal about 40 mm long. It will have a violet and a black wire going into it. From the pump half of this connector there should be a red and a white wire going into the pump motor. The white one is earth and it changes to black inside the connector. The black wire runs back to the connector I mentioned near the under dash fuses then into the main harness and is earthed at what the book says is a body earth point at the right hand wheelhouse (drivers side front wheel) for the main harness ( the big one that goes through the firewall and contains the under bonnet relays and fuses and the instruments) and the battery harness ( the one connected to the battery and starter motor).

That is the point where the fuel pump is earthed. If you have a multimeter you should get a reading if you connect the leads to the black wire in the white connector at the pump and a clean point on the body. If there is no reading then you have a break in the earth circuit. Find the body earth point near the wheel and clean it. Make sure the wire is properly connected to the terminal that is attached to the earth point. The same applies where the wire goes into the connector down the back. If there is still no reading you will have to find the under dash connector because that is the only other break in the wire.

This under dash connector should be somewhere near the driver's knees. Half of it is attached to the harness going down the back and the other half to the main harness behind the dash and instruments. It is rectangular in shape and has provision for four wires. The four coming up from the rear will consist of two blacks plus a violet and a violet/red. The black one on the same side as the violet wire is the one you want. The other is a combined earth for the rear lights and fuel gauge sender unit.

Once you get power to the pump and it is earthed properly it must work. I could not imagine all of the pumps you have tried being faulty so the problem must be in the wiring.

Try that and let us know what happened.

Brian

 

[Burnout_bro]

no power at all to the pump, thats why i dont know whats going on, even my auto sparky mate doesnt have a clue everything seems to be perfect but its not.

 

[Matt_vp]

did u check the light?

 

[14secvp]

has it got a key in the glovebox or passenger doorshut if it has give it a wiggle its for a factory fitted immobilizer that stops the fuel pump and injectors the key switch sometimes stops connecting.if you crank it for a while does the engine start have to crank it till the oil pressure light goes out

 

[BrianH]

I mentioned a wire branching off from the pump circuit and running to the anti theft emergency switch in my first post but I had forgotton about it. It is a possibility but unfortunately I dont have the manual that covers its operation.

In the diagnostic section of the engine manual, it shows the circuit for the theft module and the emergency switch. They are wired in parallel and are in the line that supplies ignition voltage to terminal A6 on the ECM. It says turning ON the emergency switch located in the glovebox (some are on the passenger's side A pillar) bypasses the module. When you look at the circuit it is easy to see how that happens.

I just had a look at the switch I took from my car and checked it with a test light. The car was dismantled and I am using all of its mechanical parts and wiring in another project. It does not have a key but the car was running when I took it out so it must have been in the ON position. This was confirmed with the test light. It has four wires about 30 mm long running to a plastic connector. Two are pink and pink/black while the others are orange and orange/black. The pink and pink/black are the two between the ign and the ECM and the others are the orange one running from the splice in the pump circuit to the switch and the orange/black from the other side of the switch to the theft module.

It looks like you turn the key to ON, the two pink wires are joined, the anti theft module is now bypassed and you can drive the car. In the OFF position the module is energised and many other circuits, including the fuel pump, are now disconnected. Maybe someone else can confirm this.

If this is the cause of your pump problem then try turning the switch with the key as Spanner suggested. If that does not change anything then pull the connector apart and bridge the two pink wires. That is the same as having the switch in the ON position. The other two wires will be left open circuited which is what happens when the switch is ON so everything is normal.

This means power should now be coming from the A1 terminal on the ECM via the green/white wire to the pump relay when the ignition is turned on. The relay should work and the engine should start.

Brian

 

[peter65]

hi BrianH... just had a look at the wiring schematic (helping on another thread) and confirmed what you said about the immobiliser switch.

The two pink/blacks are connected when the switch is operated, as are the black/orange and orange wires connected when the switch is operated.

Cars with a body control module (bcm) have an additional black wire on the switch where the single orange wire appears on the non-bcm cars. The pink/blacks are unchanged.

cheers peter.