MAF noisy on 2.0 LTG engine swap.

[twistedtx]

Hey Guys,
Im not a tuner but I am using HP to scan a recent engine swap that I have done. The problem is that I have a horrible MAF signal. it bounces from zero to 4000HZ constantly.
So here is a little info on the build:
The engine is a 2016 Cadillac ATS 2.0 LTG and I built the harness myself(because I couldn't find anyone to do it) and so far everything works.
I have grounded everything exceptionally well and moved to the MAF around looking for a cleaner signal. I have OHM'd the wires and there isn't any resistance in the circuit that shouldn't be there. During the replay of the LOG the signal looks stable but its not and doesn't look that way during recording. I have scanned other cars that i have around the shop and their signal is stable and consistent. Any advice would be appreciated.

[5FDP]

Tried putting an airflow honeycomb in front of the MAF yet?

[twistedtx]

Tried putting an airflow honeycomb in front of the MAF yet?

Yes I have. I have tried as many tricks as i know to try to smooth it out but the thing that is confusing is its bouncing all the way to zero and back up like there is a bad connection somewhere but the wiring is all good.

[5FDP]

Okay. And this may even sound stupid but what if it's installed backwards?

[cobaltssoverbooster]

has an arrow on it designating flow direction...easy check

[twistedtx]

Yes it is in the correct direction. I actually tried it backwards just looking for an issue and it didnt help.

[twistedtx]

Here is a video of the data log.

[TurboCobalt]

Can you post a log please? My guess is electrical problem? Bad sensor?
I know I?m reaching here but you could twist the ground and frequency wires together in a twisted pair to avoid any electromagnetic interference? If you have a super short induction it might also be reversion? But from the video I?d guess electrical problem.

[twistedtx]

Yes I will attach a log but when playing the log back it all looks stable and normal. I have replaced the sensor with an AcDelco.
I have been trying to shield the wiring but i haven't done the twisted pair thing yet but I most certainly will. I have broke the wiring down to the bare minimum and ran my finger nail down the wire trying to find a weak point but there is nothing wrong with the wiring. I haven't given up on it yet but I am pretty confident in this particular circuit. I have attached a couple pictures of the what I am working with and just how torn down I am with this harness. please keep in mind this is a rough draft version while I am trying to figure out if it works or not before I pull it back out to put loom on everything. Also I do know that the location of my MAF sensor is not the same as stock and it is a different size of tubing, that is not what is causing this particular issue. I have attached the OE air box and I still had the same problem.wiring1.jpgwiring2.jpg

[cobaltssoverbooster]

disconnect the maf sensor and push all the pins out. retention them and install it again to check for harness fatigue.
have you tried a new maf sensor or a second one from another running vehicle?

[twistedtx]

I have tried to post the log and some pictures but its not working. So hopefully this time it will work.
TurboCobalt.... I have replaced the sensor(twice) and really checked the wiring but I haven't found anything yet. I twisted the ground and signal wires together and that didn't help either. wiring1.jpgwiring2.jpg

[twistedtx]

Here is the log[ATTACH]78617

[TurboCobalt]

Sir, you are absolutely asking for electromagnetic interference problems.

I don't know if that's causing this particular issue but i can guarantee you will have EMI problems with the way that harness is spread out in the pictures. Did you notice that your MAP signal and your fuel pressure signal are also very noisy?

I think you should follow cobaltssoverbooster advice about checking the electrical integrity of the wiring. but while you have it apart please bundle all the wires from the MAF together. And i mean not just a zip tie every foot, I mean allow no "air" between the wires of the MAF, and not just from sensor to firewall, but all the way to the ECM connector. I still think you should do a twisted pair of the frequency wire and the MAF sensor ground. bundle tugether all your fuel injector wiring and your coil driver wiring. Do not cut corners with this, bundle the wires tightly all the way from the connector at the ECM to the connector of the injector/coil. Just because you can't see EMI doesn't mean it doesn't exist this is a very real problem, it is amazing how critical this is to electronics. make sure injector wires and ignition coil wires do not pass through the "loop" of the MAF sensor wires.

What i mean by loop is: if you consider a signal wire and a ground to any sensor if you spread the wires apart they create a "loop", That area of that loop, the area between the 2 wires is directly proportional to the amount of "noise" that those wires will pick up, that's why it is so critical to reduce that area by bundling the wires tight. Same goes for any "noise" transmitter, such as injector wires, the larger the loop area the better they are at transmitting "noise" for a sensor to pick up.

Make sure the 5V source and the grounds you used for the MAF sensor are the ones that the OEM uses, not just any 5V and any ground pin you found.

awesome project by the way, care to share any more pictures?
pease let us know if you fix it.

[twistedtx]

I have done the twisted pair for the MAF already and it didn't seem to have any result. At one point I had this harness complete meaning that all the oem harness was covered with the oem loom and tape. I didn't go into the engine side of the harness until I had a problem with the MAF. So what I am saying is that wouldn't the stock wire covering had been enough bundling to have fixed this issue? I am more than willing to redo the wire routing and make sure that I have eliminated the noise but it really hard to work on a harness inside a bundle.
TurboCobalt Yes I did notice that I have other noisy signals but the noise is much less and I do figure that they will be cleared up once I get everything cleaned up and put inside loom. I really appreciate the help btw!

Here is a pic we got of the car right after I finished it but still waiting on the wiring harness (vender screwed us and never did come through but has our money lol)IMG_75422.jpg

[cobaltssoverbooster]

twisted wire helps to a degree, 1 twist per inch is the standard but its more common for critical low signal sensors such as cas/cps sensors. the maf usually reads as this heavilly oscillation signal and gets cleaned up by the ecu courtesy a uF capacitor internal to the board. The capacitor works as a dampening factor and smooths the standard maf signal out.
It does seem you have a ground signal error. Make sure your not sharing grounds with the ignition system ex: head mounted grounds attached to the body. As mentioned they should all return through the ecu.

Is this a custom harness or extended factory harness? double check ecu pin locations. The maf didnt show any significant airflow increase when it got revved up. Makes me question pinout locations if its custom.

[twistedtx]

So I wanted to give everyone an update on the solution to this problem. after many weeks of beating our heads against the wall we finally just decided that we needed to try a new ECM. This process isnt easy for a rig like this because the dealer wont even consider touching it and when they do it usually screwed up anyway so we finally found a used ECM and it literally cured all of our issues. The noisy signal is perfect now and all is as it should be. We have a few trans issues to work through but we are on the down hill side for sure. thanks for the help guys. it is much appreciated!

[ZeroBoostBuick]

You log, MAF Hz in my scanner doesn't go up and down like in your video. In my scanner, the MAF Hz fluctuates 30 hz maybe 40 hz max.