Hi, I have a 1986 firebird with a fuel injected 2.8L v6. It was giving me the service engine soon light and I did the paperclip trick to get in return a code 54. I've looked through the other forums but can't find anything that works. I replaced the fuse on the passenger side hanger and sprayed the relay switch with electrical contact cleaner, which made the light turn off for a day. When I turn the key to the run position, I can hear two distinct clicks, (i'm assuming from the relay switch), but that's all, until I turn the key back to the off position, when I hear something that sounds like a spraying sound. The "spraying" stops after two seconds. I tried sticking a mulitimeter in some of the switches, but couldn't get anything to read. I'm assuming that was user error. The car runs great, just takes a little longer than I would like to start. Any suggestions?

 

Voltage at the ecm b2 while running ?

https://www.thirdgen.org/forums/dfi-...l#&gid=1&pid=1

 

The 2 second noise is fuel pump prime

 

Do I test the voltage with it disconnected from the switch? Are you measuring it in AC?

 

Scratch that, well digging around I think I found the problem. Where does this go?

 

That’s the ac compressor plug. Has nothing to do with low fuel pump voltage.
your car is dc. Measure the power at the ecm while the car is running.

 

Forgive me for asking but where is the ecm?

 

Under the dash on the passenger side of the car.

 

Down here?

 

It’s in a bracket hooked to the dash frame below the speaker. Accessible from under the dash.

 

 

It reads 14.71 at the ecm

 

Then if your still getting the code 54 could be a bad ecm . Or a intermittent power issue.
splice, ops .

 

I played around with the fuse on the passenger side wall some more, that seemed to have fixed it... When I took the ecm out I found yet another disconnected wire. Know where this one goes?

Thank you for your help

 

These schematics are from the 86 Shop Manual and for the 2.8 MPFI:






Hope they help !

 

It certainly did, thanks!