I have a 1991 Nissan Maxima SE. My problem is that my fuel pump is not coming on when I put the key in the on position. I pulled the fuel pump out of the car and hooked up directly to the battery to see if the pump would come on and it did. My other problem is that I'm not getting any fire to my spark plugs. I replaced the coil the ignition module and still no fire to the plugs. I took it to a local shop and the mechanic said he was 100% sure that it was the computer. The mechanic replaced the computer and still no spark to the plugs and no fuel pump running. I've also checked all my fuses and relays because I bought the manual for my car and I still couldn't figure it out. All the relays and fuses were good. Any help or sugestions would be appreciated.

 

There are 3 parts to the ignition system, the ignition coil, power transistor and distributor. If you had the nissan service manual there is a diagnostic process which allows you to check all this. As for the fuel pump there should be a relay just for it. I don't have a 3rd gen FSM so I can't scan/post the diagnostic steps .

 

I imagine the Maximas fuel system is a pressurised system. Therefore if the fuel pump works with 12v applied to it then the problem must lie with the fuel pressure regulator.
If the regulator is saying "I've got the right pressure" then the fuel pump won't work.

Brent.