I have a 1986 Fiero, V-6, 4-Speed Manual Transmission

I have not been able to get the fuel pump relay to do it's job. I have replaced it 3 times with a new one, and no fix. Fuse (position 2 in the fuse box) is good and I even replaced it.

I get constant 12 VDC at the fuel relay plug, and I can even jump the fuel pump at the plug, fuel pump activates with no problem. The car does run off of the oil pressure switch.

I do not get the fuel pump to activate if I jump it at the ALDL. I say again, I do not get the fuel pump to activate at the ALDL. I used to, but not now. I was not getting the prime, so I bypassed the prime circuit with a toggle switch. That was working just fine until recently. Recently, I lost my toggle switch prime, so I started troubleshooting when I found that the jumper at the ALDL was not working either. I copied a schematic from this site, and I will trace from the fuse box to the pump and reverse with a test light to confirm the status of each leg of the circuit.

I have concluded, from how I power the fuel pump, that a new relay does not get me the prime or activate the relay (oil pressure switch being the exception)

I want to try a different ECM.

Does anyone have a working ECM that I can try or buy? 1986 V-6, 4-Speed Manual Transmission - thanks

Any 86-88 ECM will work. It will be a 1227170. But swap the prom from yours to the new ECM if the new one is from an automatic. An automatic prom will run but not work right in a manual. Any 86-88 ECM will work too with an 86-88 prom.

Any 84 ECM or any ECM from a 4 cylinder will not work.

You can use an 85 V6 ECM (1226869) but it needs the manual trans prom. Also, you can't swap proms between an 85 ECM and 86-88. It won't work. 85 ECMs need 85 proms.

[This message has been edited by TK (edited 10-19-2020).]

Thanks, my head is spinning now.

No problem, I will get an ECM and switch out the prom

By the way, I found the problem with the fuel pump relay. It was the fuel pump relay ground. Everything is working as expected now.