question about maf sensors

SouthArk370Z

Since, as phunk said, it is unlikely that both MAFs went out at the same time, I'm still leaning toward a high resistance somewhere in the wiring common to both MAFs.

You said you had 12 and 5 V at the MAF harness connectors but that was at no (electrical) load. To check for high resistance between source and sensor, you need to check V when the MAF is operating.

But it's possible that they went bad together. With all the other problems you are having, it wouldn't surprise me if they all have a common cause, ie, wreck, water damage, etc. I'd see if I could find someone that would loan me (or sell cheap) a known good, used MAF and see what it reads before buying a set. If the same MAF is used in other, more popular Nissans, it will help your search. CourtesyParts.com has a good parts look up for 370Z - look and see if they have some kind of cross-reference for part numbers.


Edit: Or you could have a problem totally unrelated to the MAFs. Lots of weird things going on with your car.

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Z_ealot

Did exactly that while i was waiting for a response....both connectors show 12V or above while engine is operating and same for the 5V reference wire

Edit: went and double checked since i could not remember exactly....both bank 1 and bank 2 12V wire reads 14.1 volts while engine is running while bank 1 5V reference wire reads 2.54V and bank 2 5V reference reads 1.30V while engine is running and harnesses are connected to mafs

SouthArk370Z

Maybe you do have two bad MAFs.

Have you cleaned the MAFs and changed air filters?

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Z_ealot

Cleaned the mafs multiple times and air filters are brand new changed out 3 months ago and no leaks or blockages in intake tract or intake manifold

Z_ealot

just an update, but I decided to disregard the maf sensors for now and look at the main issue which is the fuel trims indicating a lean condition. decided to start with the simplest thing I could think of which is the vacuum hoses and pcv hoses and valves. brake booster hose and all other hoses connected to the intake manifold or had anything to do with vacuum checked out visually OK so moved on to spraying around each hose to see if that did anything....nothing. lastly decided to pull off the hoses for the pcv valves and guess what I found.....a nice little puddle of oil on the connectors where the pcv hoses meet with the intake manifold. pulled the hose off the pcv valve itself and same thing so popped one of the pcv valves off for testing and here's the video of what I found.....



if I remember right from reading around these valves shouldn't be hissing like that and there should be next to no suction at idle if the valve is operating correctly, can anybody confirm this or am I getting faulty information?

P.S.

when holding the valve in my hand I can feel vibrations coming from it while vacuum is being applied to it.

Dreadnaught

It sounds like there is a hole in the PCV hose where it meets the intake. This could definitely be why you have been running lean since there is unmetered air entering the engine.

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