Alright so I got an 86 trans am 305 tpi and the fuel pump fuse by the battery pops when ever I turn the key to prime the pump I changed the old gas tank and the entire sending unit as well as the fuel pump relay. Then it had a miss in it but it would run and only occasionally blow the fuse, so I changed the injectors and it ran for few seconds until the fuse popped. I've used several 20, 25, and 30 amp fuses but they all popped. I got the car and I can see that the wiring has been messed with some.

Any help would be much appreciated.

Also if anyone with an 86 t/a could send some pictures of the wiring by the battery would be a help as well.

 

This diagram is from an 87 TPI so it should be very similar ( maybe exactly the same ) as your 86. Whatever is causing the problem is probably shown in these 2 schematics.





Check 'easy' stuff first: If the fuse pops EVERY TIME a new fuse is installed & the key is turned,.......

Disconnect the fuel pump at the tank and turn the key to see if the fuse pops. If it doesn't pop than wiring in the tank is suspect.

Reconnect the tank harness, disconnect the ECM and turn the key to see if the fuse pops. If it doesn't pop than ECM - or wiring - is suspect.

Reconnect the ECM and disconnect the Relay and turn the key to see if the fuse pops. If it doesn't pop than Relay - or wiring - is suspect.

Reconnect the Relay and disconnect the Oil Pressure cut-off then turn the key to see if the fuse pops. If it doesn't pop than switch - or wiring - is suspect.

Reconnect the Oil Pressure cut-off switch

"Jump" the fuel pump with 12 volts for a second or 2 ( forced pump prime ) and see if the fuse pops. ( see if "switched ignition" power is causing the fuse to pop or if 12 volt directly on that circuit is causing it. )


Something on the fat ORANGE wire (circuit ) is causing the problem; just got to keep probing / testing till you figure our what it is !