Running Rich as Hell Under Full Boost HELP!!

[MattiasJacobs]

Fuel pressure regulator?

[BrianV8]

its a sard, maintains perfect pressure at idle and full boost.

[Black BNR32]

tested maf output and tested its wiring yet? pulled the plugs after a wot pull just to be 100% sure its actuallly running rich? maybe try replacing any necessary wiring related to the maf? i mean jeez, its just screams maf issue to me!

[BrianV8]

yup maf and outputs all tested good, replace the plugs today and they were turning dark from running rich. Ya i know i keep saying maf too but i replaced it even with no luck I don't know what or where to go from here

[BrianV8]

if it were the maf would it not effect the entire map and how the car runs vs just when the cars under boost? Besides running rich under boost the car drive and feels perfect

[Black BNR32]

in 'open loop' fuel control (wot, full decel, cold start, etc) only the maf, not the maf + o2 sensors, affect air fuel ratios.
in 'closed loop' control (part throttle, warm idle, etc) both the maf and o2 sensors work to control air fuel ratios, with the o2 sensors being the primary controllers.

it sounds like you only have problems in 'open loop'.

you need to ensure there's no problem in the wiring between the maf and ecu.

[BrianV8]

yup you got the problem bang on. I've traced every wire back to the ecu checked for continuity and resistance it all checks out. Only thing on the whole car a buddy mentioned was i have not physically checked the injectors. Resistance across them all checked good but i may take them in get them flow tested and such just to make sure. Those are physically the only thing i have no tested so my last ditch effort unless someone has another option?

Thanks for the input guys!!

[BrianV8]

K well here's an update, decided to tune my problem out and discovered the O2 sensor was hiding some of the problem, turns out the entire fuel map went rich not just under full throttle.

So what would cause that? Having the entire fuel map turn rich.

[cschepp]

Brian maybe something to invest in would be another ecu. I know on the power fc the fuel displays on there and monitors many things for you. I have available that I'll give you a good deal on.

So a couple questions now.... Did you replace the o2 sensor, did you have the injectors flow tested, also when the guy did your mistune did he set the proper values for your z32 maf? Marc(nelsonmx) had this problem and couldn't figure out why but then figured out when putting in the different values it solved all the problems.

[BrianV8]

Brian maybe something to invest in would be another ecu. I know on the power fc the fuel displays on there and monitors many things for you. I have available that I'll give you a good deal on.

So a couple questions now.... Did you replace the o2 sensor, did you have the injectors flow tested, also when the guy did your mistune did he set the proper values for your z32 maf? Marc(nelsonmx) had this problem and couldn't figure out why but then figured out when putting in the different values it solved all the problems.

Ya i thought ecu also. I have a spare that worked fine. Threw it in with my chip and made no difference.

I didn't replace the o2 because it seems to be an open loop problem. In closed loop the o2 works perfectly to maintain stoichiometric ratio.

Another guy mentioned injectors and yup i had them flow tested. They came back perfect. No leaks and all exactly the same across the board.

I tuned the car myself using some software a buddy hooked me up with. Worked really well. Before i got started he took an rb25 stock tune and modded it for my z32 MAF and 550cc injectors. It worked perfect until something changed a while back.

Ya i totally agree it seems like a MAF or injector value somehow flipped on me. Just because it went rich by the exact same amount across the board. In order to rule out the tune i had buddy varify the calibration to the maf and injectors. Reburned the chip along with another chip to make sure and no luck. Next thing i think i'm going to attempt is turn the key on and go through each pin on the ecu while plugged in and make sure all the values its seeing make sense. Hoping to maybe find a short or something. I really don't know.

Thanks for the help though man. Great suggestions for sure. Would love to get this sucker figured out before i have to take the car off the road for winter.

Thanks again! Brian

[BrianV8]

well just an update I went through all the pins on the ecu and best i can tell all is normal as far as voltages go. Unreal.

[cschepp]

Are your injectors high or low impedance? Also I would change the o2 sensor just to be sure.

Now another thing you do have a bov going to atmosphere correct? If so you don't feel any loss in power or anything? If you would have a leak or anything like that this could trigger something like this wouldn't it? If you have gone through the injectors, maf, and the ecu I by now would sorta count those out. I would try to look for small leaks with either propane or even carb cleaner as they will both work great and then hopefully that would help out with finding the problem. I could see it being something like this if the problem just randomly started to occur.

[BrianV8]

well injectors use the gtr resistor pack so i believe they high impedance? BOV had dumped atmospheric since the day i put it in. I know as a fact from boost testing it does have a tiny tiny leak, but it has done that since day 1 so not counting on that being the problem. I did try using propane to look for leaks with no luck. Got better results with the boost test but once again not the issue. Other reason i don't think its boost leak is like i said earlier it does not have to have boost to be rich. Tables seem rich entirely.

[GTRADDICT]

A/F gauge could be wrong?

[cschepp]

Ya what Wideband are you using?