Couple computer related questions regarding my upcoming engine install.

[87gtVIC]

1. Can I wire the ECM connector for my mass air computer (A9P) but plug in my speed density HO computer (making sure to also supply manifold vacuum to the MAP sensor) for initial start up?

Yes, I know that the TAB and TAD wires will be in the incorrect position, though in the grand scheme of things they are deleted anyways….

Any thoughts, aside from it being silly to do this in the first place?

2. I would like to wire in the FPM at connector 19 for the mass air computer, now is that simply a 12dv+ after the fuel pump relay to tell the puter that the pump is theoretically receiving power?


Little background on the spec of the build:
• TFS top end kit but with explorer lower intake and lightning tubular upper
• Deleting smog pump, TAB, TAD as well as EGR (because the heads do not support EGR).

[gadget73]

1) don't see any reason why not, but the smog pump solenoids will not be connected to anything on the SD brain, so you'll get some codes about that. You will need to add the VSS wiring as well, which is likely not present on an '87. Same with the fuel pump monitor wire. As far as I can tell, none of those pins are used for anything on the stock ECM so connecting them should not cause any problems. Won't absolutely guarantee that. Might be safer to put the wires in but not actually connect them until you're ready.

2) Yep. Connects to the pump side of the fuel pump relay. It works without it, but you get a nag code if you don't hook it up.


If you're having it tuned, and you likely will need to, you can shut off the smog crap entirely so the nag codes go away. At that point you can just shitcan all 3 of those solenoids on the fender. They won't be doing anything useful anyway. I suspect the fuel pump monitor could be turned off too, but its easy enough to hook up to not really be wort bothering over.

[87gtVIC]

I shitcanned the three solenoids on the fender this morning. I'll get the nag codes for all of those regardless of what pinout and computer combo I use.

The VSS is something I have to look into. I hope that the VSS (+) and (-) are under the hood somewhere so it is easy to tap into and route some wire to pins 3 for the + and 6 for the -...Though, again, I need to look at my EVTM and see if they are already at the computer or somewhere else.

I will go ahead and connect that FPM because all the wiring will be easy to get to. I see no reason not to. One less thing for the tuner (yes it will be getting tuned) to click.

[86VickyLX]

Yes. Just leave the unused pins alone for right now. And don't have the MAF plugged into the harness. Not sure what would happen if it was plugged in.

[87gtVIC]

SO No to repinning for MASS AIR and leaving the mass air sensor unplugged?

I planned to repin the connector for mass air but leave the mass air sensor unplugged and do the initial startup on the speed density Mark VII ecm I have.

I don;t know exactly what you are yessing John.

[86VickyLX]

Repin but leave the MAF unplugged.

[87gtVIC]

Copy that.

[mitymerc]

I drove the Capri around for a while w/no MAF as it was @ Pro M being calibrated. As far as I recall it ran ok.

[mitymerc]

Now that I am thinking about it, I believe it was SD processor plugged into the MAF harness....