'94 Sentra starting head scratcher

[Tugboat555]

150,000 miles - the car has been sitting for about a month. Tries to start, but fuel pump cuts off. New battery. Has gas. Fuel pump works fine on the bench. Jumping the contacts on the fuel pump relay, pump works fine, car runs properly. No control power to the fuel pump relay. Fuse checks fine - replaced it anyway. Chilton manual is vague concerning the electrical circuit for the fuel pump. Is there any device in the circuit that would cause the pump to shut off? Any way to test the ECM before coughing up the big bucks for a new one?

Thanks
Tugboat - cheapskate

[jetfields]

I took my car to the dealer because it would have trouble starting every once in a while...and when I was at high speeds, the RPMs would go to zero for a split second and then bounce back up. It's a Sentra 2001, with 95,000 miles on it. Anyhow, the dealer said it needed a tune up. I said I would pick it up to take care of that. They called a day later and said it needed a new ECM. When I went to pick it up, the car was inoperable and they told me it would need to be towed off the lot. Obviously, I don't trust the dealer at this point, so I'm wondering if I should proceed with towing the car and trying a tune up...or should I buy the ECM and have the dealer replace it? Any suggestiongs are appreciated!