I am not getting enough power to my MAF. Reading should be approx 12v at the MAF connector power wire, which is the red or #3 wire. I only get 5v. This is causing a CEL and making the car run WAY too rich at idle. Car is a 1998, I have tried two different ECM's, both read the same voltages. Things I have checked so far-

Using the FSM
Checked voltage at the ECM, getting 11.6v at connectors 67 and 72, which supposedly supply power to the MAF, per page 282, EC-114 of the FSM.

Running a Z32 MAF and injectors. Have checked the voltage levels at the splice and the connector to the MAF, both read the same. Checked by grounding to both the harness, and the chassis, voltage does not change, stays at 5v.

Checked a known good Max, power at MAF connector was 11.8v, as it should be, key on, car not running. Checked Z32 Maf on a known good car as well, MAF is good. I am positive this is a car wiring issue, and not directly related to the MAF itself.

Per FSM, when voltage level is not correct:
"Check the following.
*Harness for open or short between mass air flow sensor and ECM
*Harness for open or short between mass air flow sensor and harness connector F36
If NG (No Good), Repair harness or connector"

So I have checked and voltage is not where it should be. I then checked the ECM, and it is putting out proper voltage. Which leads me to...

Why am I only getting 5v at the MAF connector? If it was grounding out somewhere, I shouldn't even be getting that. I have been back and forth through the FSM and I am not sure what I am missing at this point.

Anyone know what I am missing?

 

Per the FSM, the power for the MAF also runs through the ECCS relay. Perhaps a bad relay? Checked through all the FSM but could not find any procedure for checking it, or the related wiring. I'd just go buy another relay, but all the parts departments are closed today. With the wiring diagram in the FSM though, if I am getting good power to the ECM, then power should be good to the MAF, as far as I read it.

Ahck!, I hate electrical problems.

 

I would just bypass the stock wiring and tap into the wire directly out of E13/F36-7.

 

That is what I may end up doing. I'm just concerned about where the problem is originating, I don't want it to lead to other issues down the road. The car did not have this problem before I pulled the motor. I may do it just to see if it fixes the running rich issue.

 

These are the most aggravating problems because you know it's your fault!

That said if you run new wires and check the relays it should work and I don't see where this would result in errors down the road.
When the engine is pulled you know anything can happen to wiring.

Just the other day I had the drivers side HD headlamp wiring apart to get to something else and I reversed a connection and this drove me crazy for 2 hours finding out why the light didn't work.