MAF - Parts Cannon Story - Paying it Forward

[Schurkey]

en fixing cars for 50 years to me new stands for never ever worked

Huh?

 

[L31MaxExpress]

Huh?

He is talking about new parts being DOA.

 

[OBS_Trash]

Well y’all, I’m defeated.

MAF connected runs with slight mis-fires counts on random cylinders. With out DashCommand I couldnt tell. Once she gets up to about 60mph backfires (kinda warm weather) previously cold weather no issues. No codes.

When I unplug the MAF and she toggles to to Speed Density purrs like a kitten. Driving all speeds, no mis-fires. So until I can get my hands on a OEM MAF from another solid running truck just to ease my curiosity I’m going to run no MAF. Check my plugs later to see wear. But she drives great. It needs the MAF to start, so I guess she is getting a kill switch, I already have the stuff.

 

[454cid]

Well y’all, I’m defeated.

MAF connected runs with slight mis-fires counts on random cylinders. With out DashCommand I couldnt tell. Once she gets up to about 60mph backfires (kinda warm weather) previously cold weather no issues. No codes.

When I unplug the MAF and she toggles to to Speed Density purrs like a kitten. Driving all speeds, no mis-fires. So until I can get my hands on a OEM MAF from another solid running truck just to ease my curiosity I’m going to run no MAF. Check my plugs later to see wear. But she drives great. It needs the MAF to start, so I guess she is getting a kill switch, I already have the stuff.

Id recommend watching the signal from your maf, if you can graph it.....can dashcommand do that? When my maf went bad it was reading low at idle.

 

[RichLo]

Yea, graph it and put the screenshots up here if you can. I may have missed it but have you checked for damaged wires yet? Mouse damage, or cracked/burnt connector

 

[L31MaxExpress]

MAF should also be grounded on the front RH side of the engine, near where the fuel pump would bolt in place on an older engine. Those love to corrode.

 

[OBS_Trash]

I love everyone's enthusiasm, thanks Fam cuz im whipped.

@454cid The app as awesome as it is, does not graph. I am in line for the Scan tool in this forum. I want to graph the fuel trims against each other with and without MAF, Annoying because i work at a chemical production plant and the DCS all i do is trend variables to troubleshoot unit and equipment issues. Be nice here. If i get my hands one i will post all pics here.
@RichLo Wires good, voltage checks out, including Ground
@L31MaxExpress Looks ok, I also inspected the ground straps and they look "OK" nothing obviously bad. I bought new ground straps too that i plan to install (3 of them). However the ground checks out as well.

 

[Pinger]

Re MAF sensor. When I had mine non-functioning (missing fuse) the upshifts were hard. Apparently, the PCM reads from the MAF sensor to set line pressure in the trans. No signal and it resorts to maximum line pressure hence hard upshifts.
The quality of your upshifts may shed light on how well your MAF sensor is functioning.

How are your upshifts? My experience with my 1999 5.7 is that they are hard when the MAF sensor is off-line. If yours are acceptable then I think you can take that as a sign of a functioning MAF sensor. If not, then the converse.

 

[RichLo]

The app as awesome as it is, does not graph.

Oh yea, that one doesn't, that's the one I have for extra fancy gauges in my dually, lol. Try downloading OBDLink app... That one you can graph up to 4 sensors simultaneously. And you can erase codes on the fly while driving with that one too.

 

[454cid]

So you're aware, the output from the MAF is a frequency, not a steady state voltage. It's interpreted into a grams/cubic-centimeter number by the PCM.