Hi this is my first post


I have 86 iroc with tuned port, setting up for a while, cranks but no start. no power to fuel pump, inline 20a near battery is good, replaced fuel pump relay near brake booster, fuel rail reads 0 psi when cranking over but I get about 30 psi on oil pressure gauge, test terminal (B) adld reads 5v, test terminal for fuel pump (G) sends varies readings on multimeter - OL..OL..OL, like meter cant tell what voltage, I know its supposed to be 2-5v, but all I get is sporadic reading. When I short B terminal to ground, fan goes on and I get service code "12", no other codes. Any idea what else to check, not sure how to check fuel pump switch (oil pressure sender) or ECM for voltages. Any help will be greatly appreciated.

 

Locate the fuel pump connector at the back and test for 12 volts when cranking (light blue wire). If 12 volts present, most likely the fuel pump is toasted. If 12 volts not present then you have to work backward. ECM activates fuel pump relay (dark green/white wire at relay). The fuel pump connector could be under the vehicle against the floor pan in the rear end area or under the carpet behind the back seat. I'm not familiar with 1986 model. The oil pressure switch sender is a back-up and does not control the fuel pump.


Best of luck!

 

no power at fuel pump connector, anyone know troubleshooting process

 

Probably tons of post on this

 

 

Large gauge orange wire at relay (A) has voltage, when I jump to relay (E) all I hear is clicking from relay, I disconnected the 3 wire connector at the fuel pump, tried jumping the relay (A&E pins) and checking for voltage at the 3 pins and no voltage, doesn't look like power going to the fuel pump connector, maybe ecm issue or maybe an issue with a chewed wire ( I always worry about mice), any more troubleshooting tips would be appreciated

 

Large gauge orange wire at relay (A) has voltage, when I jump to relay (E) all I hear is clicking from relay, I disconnected the 3 wire connector at the fuel pump, tried jumping the relay (A&E pins) and checking for voltage at the 3 pins and no voltage, doesn't look like power going to the fuel pump connector, maybe ecm issue or maybe an issue with a chewed wire ( I always worry about mice), any more troubleshooting tips would be appreciated

 

**should note the relay clicking was after I disconnected fuel pump connector at rear near gas tank, when this connector was hooked up the relay just made one click sound but still no fuel pump sound

 

Plug the fuel pump and engage the relay. Check voltage reading on orange wire and on light blue. Make sure when you check that your voltmeter ground is at the battery. Sounds like maybe a drop in voltage when pump engages thus pump toasted or could also be a bad ground.