Thread: SIGNS OF A BAD MAF sensor

You might be onto something with the wiring. I had an issue come up on my NX, where it would be fine, then all of a sudden would cough and sputter like it was under/over fueling. A quick look at the fuel pressure revealed normal readings. I was able to duplicate the rough idle condition by jiggling the MAF harness. Turned out, the ground wire (which had been previously repaired) was down to it's last couple of strands, and was reduced to making intermittant contact. Sometimes, revving the engine was enough movement to induce the sputtering. A rewire solved the problem. The culprit was indeed the grounding wire.

Darrin

Just get a used (but working) MAF off a forum member. I just picked one up for $25 shipped.

well my maf's reading was good so i dont think its my maf its more like an electrical problem. The car looses power all of a sudden and then just dies. Im still thinking theres a shortage somewhere going on the wiring, im going to take it to the electrician and see whats up.

take it to an electrician? f that noise - get a set of sewing needles (the thread type) from the dollar store. then take an alligator clip or two, take out the ecu and start looking for continuity on proper pins. takes 10 minutes or less

ok found out something new, i think its related to the problem, when the car its not getting enough fuel due to bad injectors the maf tries to compensate for the fuel right? so when the car is not getting enought fuel the maf cant handle and the car shuts off right? so today i tried checking my car again and it was running really lean, white smoke started coming out, and everytime i unplugged spark plug wire #1 and #4 car would shut off right away, so im thinking that when i was touching the signal wire going into the maf the connector was making ground with my fingers and trying to compensate for the gas so thats why it turned off everytime i did that right?

No to all the above, it's time for you to take it to a professional.

Electical problems are already hard to chase down in person, almost impossible to diagnose over the internet. You're wasting money by replacing parts on guesses.

dude, just get your multimeter, a case of beer, start answering your own questions, download the fsm and go out to your car, and start troubleshooting.

a professional will take that same manual and do the same things. Check anything and everything - you'll get experience from doing it, and easily find your problem within 8 hours of doing so.

sometimes it's better to just go out and work on it instead of researching until your eyes are crossed and you aren't any further ahead.

you CAN do it all yourself, you just have to make time and expect it to not come to you on a silver platter.

*edit* also worth noting is professionals will narrow stuff to 3 things and tell you to replace all 3. Case and point, last week I took my sentra to the dealership for an idle relearn - they told me I needed a new iacv and ecu because they think the iacv fried the ecu. 5 hours with a multimeter (yes 5 hours) and I eventually found a melted wire - fixed the wire, and she's running perfect. Saved $450 on parts, and god knows how much on labour. Even the pro's dont know **** sometimes, and nothing can beat the love of a man and his car - the willingness to spend the TIME to find out what's wrong. Electrical stuff can be a bitch, but it can also be very easy if you take your time doing it. Not only that but you may also find some things that need fixing along the way that could leave you stranded all of a sudden had you left them unfixed for any longer.

hahah thats what im doing i have spent three days trying to figure this out i changed my fuel pump, replaced my spark plugs, rewire my maf, put a k&n filter, checked my maf with a multimeter, i replace some cracked vacum lines, bought a new fuel filter, and new distributor and also checked all the connections, so hopefully its the injector oh i also checked my timing and bought a scanner so im gaining experience, so thanks for all the info im not expecting everything on a silver platter im actually doing this hands on, btw where can i download the fsm. Also theres 2 injectors that i think arent working like i said.

there's a sticky of mine here someplace - general sr20 I think.

Seriously, the best thing you can do is the sewing needles, alligator clamps, wiring diagrams, pull off the ecu, and start measuring continuity on your maf wires to start, then proceed from there. And stop throwing parts at it that's costly if you dont have to!

hey is this car an auto or manual btw

also check your fsm on the injectors, you can measure resistance on them. it doesn't tell you if they are leaking, but does tell if they aren't working. after that, i'd check continuity on the batt+ to ensure voltage - the ecu runs the injectors on grounds, so they would be constantly grounding then not - fast enough a conventional multimeter won't measure. Though I would check everywhere else man, our inj's are supposed to be pretty damn good and almost last to go.