fuel pump doesnt stop running

[Blue MK2]

My mate has a problem with his 8v digifant GTi.

The fuel pump doesnt stop running when the ignition is on and over floods the engine, causing it to not start.

Hes tried the relay, checked fuses etc etc with no luck

anyone know the trick to solve this?


Thanx

Blue

[benjam_in]

is there a relay involved in that circuit?

[winstonb]

isnt the pump supposed to stay on?  i think the problem is at the engine end, like the injectors are fireing when they shouldnt, or the return circiut has a fault?

[Blue MK2]

^ aint got a clue mate. just something he told me  

[benjam_in]

think he means that when u turn the ignition on initally and it primes the engine for ignition that it just carries on and floods the engine?

[richandhazel]

I 'think' (don't know the digifant as well as the k-jet) its like the k-jet system in that respect.........the fuel pump runs continually to create a constant pressure system. Excess fuel should return to the tank.  I think winstonb is heading in the right direction in what he says. The injectors should only open when signalled to do so......no matter what the fuel pressure.

[richandhazel]

think he means that when u turn the ignition on initally and it primes the engine for ignition that it just carries on and floods the engine?

Even if the pump does carry on, it shouldn't flood the engine, thats why you have a return line.......once the fuel system has reached pressure, any excess should return to the tank. If it is flooding into the engine then you have a problem at the engine end.....not fuel pump.

[benjam_in]

sounds a bit more like it! need to get my car head on!  

[Blue MK2]

think he means that when u turn the ignition on initally and it primes the engine for ignition that it just carries on and floods the engine?

Even if the pump does carry on, it shouldn't flood the engine, thats why you have a return line.......once the fuel system has reached pressure, any excess should return to the tank. If it is flooding into the engine then you have a problem at the engine end.....not fuel pump.

just had a look. yes it flodds the engine. tried my relay in his car and still no luck.

when i turn my ignition on, the pump goes on for about 3 seconds but on his engine it keeps running.

just wondering if it could be something to do with the ECU?. i have one spare for sale  

[mk1]

If the engine is flooding the injectors must be leaking or being opened. Disconnect the electrical connection to the injectors and see if it still floods. Also disconnect the ign amp as this is what triggers the coil and pulls in the pump relay, a faulty amp can trigger the coil, pump relay and injectors. Have seen a faulty ecu hold the injectors open also.
Steve.