I have a 1990 Trans Am GTA with the 5.7 litre V8 with tuned port injection.

I noticed yesterday that it wouldn't start.

Normally, when I turn the key to the "ON" position, I can usually hear the fuel pump make a "humming" sound, then when I turn the key more, to the "Start" position, the engine would turn over.

Now, however, when I turn the key to the "ON" position, I hear the fuel pump, but it is making a different sound. It makes the "humming" sound but, it also sounds like it's making a vibrating/buzzing sound. This is something totally new.

When I turn the key more to the "Start" position, the engine wants to start, but it won't turn over. This problem popped up in the past 2 weeks.
The battery was checked yesterday and its O.K.

I did notice something different about the car. I noticed under the hood, on the firewall (the driver's side), there are three relays mounted together in a group. The wiring to all three relays has been chewed. I think a mouse or squirrel visited under the hood and did the damage.

One of the relays, the one on the far right (if your standing in front of the engine), the one closest to the master cylinder, has the most damage. One of its wires is chewed almost completely through, only a thin strand of copper has kept the wire from being split in half.

Could this relay, or any of the 3, have anything to do with the fuel pump, or be involved with the car starting?

Thanks in advance!

 

UUUhhhh Yaaah.....

One of those relays is the fuel pump relay. If the wires have been partly chewed thru only a very little current can get to the fuel pump. So it would humm, however, it would not have enough power to pump fuel.

Fix all of the wires, Cut out the bad parts and splice in new wire, make sure to use the same diameter wire, or larger.