3 replies to this topic

[rolesyboy]

Folks, I have just rebuilt an MPI from scratch. Everything appears to be in its correct place. Thus far I haven't been able to get the fuel pump to activate. 

If i tip a cap full of petrol down the throttle housing the car fires up immediately suggesting everything else ignition wise is fine

When I turn the ignition on the feed to the fuel pump is live (I checked with a test lamp and it lights up when I turn the car over)

I have pressed the fuel cut off on the bulkhead but this seems to have no resistance. (My understanding was this should click like a button???  I haven't got a spare to compare )

I have taken the fuel pump out of the tank and connected a live and earth to the spade connectors and it doesn't make a sound.

I have a spare MPI tank and tried the same with that pump and again nothing which makes me wonder if I need to wire it up differently or  

alternatively am i really unlucky and I have I got 2 duff pumps? (I know one of them worked 6 months ago before I dismantled the car)

Or am I missing something here?

What is a good test procedure for the fuel pump? Does it need to be in situ to test it perhaps?

Thanks in advance. Mark

[Fast Ivan]

sounds like you have two duff pumps

[nicklouse]

the pump should come on and pressure the system as soon as the ignition comes on.

 

a buzz then stops.

[AeroNotix]

When you say you can't get the fuel pump to activate, how are you testing this? Do you mean the car won't start and it continually cranks? Does it crank?

 

If you have access to a reader, you can test the fuel injectors. Connecting 12v directly to the pump should make it pump continuously. If the fuel pump doesn't pump completely disconnected from the car you will have to trace it back from there. For example:

 

• Ensure the fuel pump works isolated from the car. Apply 12v across the pump and it should continually pump
• Fuel cutoff switch. Does the switch work? Is it plugged in? I don't want to tell you to bypass it temporarily, but you could. Make sure the wiring isn't knackered.
• Are the injectors working? Are their grounds in good condition? It's my understanding that they are ground switched and not live switched (corrections welcome)
• If it cranks, but doesn't fire, check the crank position sensor.