Mustang turbo P0104 code

[caniggia]

Hi,

I tuned such car some time ago and was running good on 60lb injectors and 8psi, but since some time they changed some things on the car (new air cleaner, return fuel system), man came for retune and there goes often usually while normal driving or decel this code.

P0104-mass or volume air flow circuit intermittent.

I changed MAF to mine and this same and played with tons of air settings as never, maf is relocated so maybe electrical problem, but for sure maybe someone knows if it can be from tune.
I have proper maf dialed, idle tables, LWFM both and so on, car runs good, except rich at decel (60lb injectors) and occasionaly at idle. I think maybe it's because of this - only think I don't like in this car. I tuned few blown cars and never had such issue.

Log attached, don't look at fuel pressure, it has damaged fuel pump they has to repair.

Thanks.

[TheVerge]

I know that I'm not a seasoned tuner but my profession requires me to analyze test data.

The major problem that I see is that your MAF sensor output V does not correlate with your MAF sensor measurement. Although the MAF V vs Mass Air Flow is not linear (mine is Y=.5334X+.288) the Mass Air Flow should always increase as MAF V increases. I did not see that happen in all cases in your data.

I would suspect that your MAFV vs Air Flow table does not create a smooth curve when plotted 2d, or there is a leak around the MAF sensor, or the wiring needs to be soldered, or electrical noise is interfering with the sensor voltage.

One thing that I did to verify O2 sensor voltages is use measure a 1.5 volt AA battery. Connect it across the sensor input and ground and data logged the voltage. The voltage was exactly what I read on the dmm. I bought a $41 (shipped) 4 channel usb dataloger from DATAQ that I plan to use to monitor boost pressure, maf v, etc. It is a really good diagnostic tool since it functions as an Oscope without having to learn any programming.

I hope this helps and good luck with finding it.

[1998Ws6]

I've never seen a P0104 code on any ford and i've been messing with them for 8+ years professionally. What kind of wiring mods are done to relocate the MAF? cut, butt connector, solder or plug and play extension?

Ryan

[caniggia]

I dont know, i was not doing this. All is isolated. They have to check this.

[caniggia]

I got this car back and I have to find now what's wrong with one instead of people installed this...

First of all we had to modify wastegate, all air connections, probably will have to change BOV, modify crank vent nad some more things.
He was blowing air to crank vent at boost and takeing unmeasured air at normal driving.
Now It drives lot better and getting 9 psi instead of 5, but maf history is still actual.

Maf readings as mass are chaotic, not volts, car is not driving fluent, he's like thinking. I logged also with SCT, looks problem is MAF, there are also chaotic readings, also with inj pulses. I checked all electicals, changed maf, and still this same. Looks also car pulls of timing when are problems with MAF readings (again as weight, not volts).

For me looks it's wrong design of intake, which is copy of Turbonetics kit named BoostBrothers. It has also honeycomb before MAF.

I disconnected all turbo parts and installed my jlt 110 intake and car started driving fluent and I found no errors of MAF, but I was not driving to much. In log I also found big spike in air, but don't know now why, maybe it has something with load with failed, maybe it has something to do even anticipation logic is off, I think about becouse voltage in not jumping only calculated weight of air.

Screens attached.

EDIT

Now with some additional test on same intake but Turbo disconnected, no MAF errors and car drives more rich (10.2 instead of 11.7) than when Turbo connected, so now I'm sure it's wrong design of intake and MAF is not measuring properly. MAF and spark curves are smooth, injector times too.
Additional we removed honeycomb before maf, and now it's not possible to drive, error p0104 after few second. So we are going to make it draw thru and this will fix problems.

[Eric@HPTuners]

Anytime you see a DTC code with the word circuit in the description, the problem is not tune related. You either have a bad sensor, or faulty wiring. I would inspect the wiring very closely.

[caniggia]

It's 100 percent wrong intake design and irratic maf readings not wiring and and not tune.

I did draw by thru and error is gone.

Car is making 470 hp at crank hp at 7 psi with stock fuel pump at 11.5 afr, before at blow thru was making 370.

Now i have rich condition at light decel, this is probably because to short intake before Turbo and air at decel is going another way than acceleration.

I don't know if this can be done in tune, like decel enleament.