Hello All,

Having read other articles online, I am still stumped…

I currently have an issue with the fuel pump running intermittently on start meaning I cannot start... Although if I supply 12v to the pump directly it runs. I will try outline what I have investigated so far.

So, when you turn the key to the 2^nd position you should hear the fuel pump whir, priming the fuel lines for ~2 seconds (if anybody knows what controls this 2 seconds I would like to know!).

However, this does not happen, even though I can measure (albeit briefly on my multi-meter) connected to the fuel pump loom 8-12v (hard to say with my meter) when the pump should prime but it does not run. When I discounted the pump from the loom, I measure 12.3v in the loom, which stays live rather than stops after ~2 seconds, which leads me to believe the 2 seconds priming is controlled by a measurement of an electrical characteristic of the pump (resistance)? Rather than backpressure in the fuel lines. The battery is at 12.8v so I do have a 0.5v drop from battery to pump, I am not sure if this is normal or not? I cannot see how it could the issue also as I can get the pump to run on 5-12v external source.

I know it is not the pump relay as when I have this jumped, I still have the issue. The fuse is also intact. The inertia switch is ok also. It is not an issue with the ignition as the starter motor runs.

I have cut a hole in the floor to access the fuel pump, all the contracts looks clean and the mild corrosion on top of the pump looks to just be on the surface and what I would expect from a 22 year old car.

My next step will be to run a new +wire for the pump from the inertia switch in the front left footwell back to the pump directly. As this will rule out any issues in the loom running around the dash and right-hand side of the car that I cannot access easily.

To start the car all I need to seem to do is connect the fuel pump to an external 12v source run it for a few seconds, then connect back to the loom. It then does start running with the engine. Once the pump is running from the car it never stops.

Any help on this issue would be greatly appreciated as I am running out of ideas!

I hope I have made the issue clear enough, please ask me about anything I may have omitted.

Thanks,

Mark

 

Hi, 

Did you ever solve this problem I'm suffering with the same issues.