Schrodingers Box part 1 reaction:
Anyone else catch that he introduced himself as MAF (Mass Air Flow sensor)? Nice Freudian Slip...not a true one, but the phrase has slowly changed to mean that something you're mind is working on came out. So cool. :)
Purposeful or not.
At 4:20, Matt (Schrodingers Box) is about to talk about IAC or the idle air control valve. While this is a bypass of air around the throttle valve, realize all the air that gets to this also has to go past the MAF. So, if you have a known expectation of your idle RPM and what your MAF could be, it could be a way with a scantool only to know if there is something wrong with your MAF. Just remember, this can be misleading as idle can be wrong for other issues like running rich. IAC will respond with more air than normal and RPM will usually be raised.
Matt's spoiler alert didn't ruin anything for me about his new tool. He had hinted at 7:20 about about another non scan tool test I was all smiles. :) I have this bad habit of reading comments before the video or as it runs, so I already new an oscilloscope was coming!
17:06 By now I'm very excited. I have successfully diagnosed two bad MAF sensors prior to this video. 1 was super easy. 2.3 to 33 g/s was normal for my car at idle. 93 g/s per second at idle and random spikes around that abnormal number as I pushed on the throttle? Okay. I knew what was wrong.
The better MAF I condemned I didn't do directly. On my car the MAF and IAT are in the same component. IAT was reading very accurately as compared to my "laser" thermometer of the intake that the IAT sat in....but when it got above 43 degrees C it would race hotter. The "hotter" the air the more the PCM believed it needed less fuel. The O2 sensor caught it and increased fuel trim.
I reference being excited by 17:06 as I realized my MAF is 100 to 200 degrees F hotter than the IAT? Well, since the IAT was getting off the more it got hotter after it's accurate range. of 43 degrees C...well hey, by it being in the same part I condemned my 2nd "MAF" ;)
By the way the 2nd way I had known to condemn a MAF (I'll go ahead and be more honest now, I condemned an IAT, it was just attached to it in the same part of a MAF, Lol) was achievable by DVOM, chart of known resistance representing what temperature and a laser thermometer.
I cross referenced my results via scan data and the laser thermometer as well. There's no way to get around that laser thermometer for this technique.
21:45 It seems to me that the way the MAF was intentionally designed was to appear to be a potentiometer. I think they avoided changing how PCM's reacted from the early VANE type MAF's and how they'd have to see a potentiometer.
So, analog MAF's appear to be engineered to me to prevent re-engineering PCMs. Sure the PCM needed the equipment to produce voltage and maintain constant temperature, but the change in V sure seems like a potentiometer.
by AutoBravado
For another article by AutoBravado discussing how I fried my MAF. The articles intention was to be about water decarbonization only, but I got into some related concepts as water decarbonization done wrong would get this sensitive sensor broken.
