Hello,

I have a 89 FC3S that I have had running for years that all the sudden won't run, or will run for maybe half an RPM then shut off. I can hear the fuel pump priming and have even straight wired it to make sure it wasn't an issue and nothing. On one of my last runs it died pulling into the neighborhood and coasted home and haven't had it run since about 3 months ago.

I've tried plugging into the OBD2 port to see what it says and it won't connect. It has in the past so the wiring is not incorrect. I thought I must have burned out my PCM somehow so I got another one with a fresh flash. Totally not a VATS issue, and same problem with new PCM. It gets 12 volts. I'm stumped. Going to have the wife turn it over later to see if I am getting power to the injectors and plugs.

Don't know what else to do.

 

These systems depend more on GROUND CONNECTIONS than power feeds. Check every ground connection there is, The ECM operates the ignition and injection systems by grounding them.

 

I would test all the power and grounds at the pcm with the key on (a marginal power or ground can show good when its not under load) check all your 5volt reference sensors to see if they are getting 5v. Ive seen sensors short out and the pcm power down to save itself. Easy test for that, unplug all your sensors and see if you get communication back, if so plug them back in one at a time time until it shuts down again.