Volvo V70 starts but immediately stalls

Thought it was a manifold air-leak but now it looks like a fuel supply problem. Pump primes OK but then doesn't supply fuel to keep engine running - so engine stalls. Stalling problem can be solved by removing fuel pump controller relay and shorting out contacts so pump is on all the time - but this causes the rev counter and other things associated with the electronics in the controller relay to stop working. Looks like ECU? If anyone out there has encountered this and knows a fix, I would really like to have my car running again!