ironmikektm525

Disconnected my battery/ maf sensor going to track. Is my 1/4 time gonna be affected
I know you don't loose your tune and fuel cures need to be relearned. Do I just drive it like normal or do I have to floor/ drive aggressive ect? Approx how many miles until I'm good? Just want to be 100% for the track! Is it best to reset fuel trims when changing a performance part? Thx

Nicelysedate

iTrader: (3)

Your short term fuel trims will fix your LTFTs over a long enough period. And if your PCM is set to operate like factory you are in closed loop for 95% of a 1/4 mile pass. MAF is being used over what ever RPM your PCM is set too. I believe it is 2400rpm stock.

98redorangeta

iTrader: (10)

If you just disconnected the battery and didn't replace or clean the man you will be fine drive around for half an hour normal driving you will be pretty close to learned in on closed loop. WOT is not going to change sine you are in open loop.

jimmyblue

iTrader: (11)

Fuel trim learning can be good or bad. If the sensors
are giving whack readings (as they do, when cold /
aged) the you're letting your PCM be home-schooled
by retards. What do you know about fuel trimming
integrity?

Nicelysedate

iTrader: (3)

This is why closed loop/fuel trim learn should be disabled until engine is warmed up.

ironmikektm525

The track is approx 1.5 hours away. So by the time i get there i should be good? Do i have to floor the car here and there/drive aggresive or normal drive? Need every .05 i can get lol. I know little about fuel trims/open/closed loop? If i didnt unhook battery would my maf adjust itself to the new cold air assembly and how long would that take? For future reference incase i change cold air assembly again. Disconnect battery or leave connected. I just did this time because i read somewhere if i had to unplug maf i should disconnect battery? Not sure if this is correct.

Nicelysedate

iTrader: (3)

Drive normal. You will be fine. Wide open throttle is controlled through the MAF and is unaffected by fuel trims. By the time you get to the track your trims will be fine for most every area that needs them.

ironmikektm525

Cool thx to all!!!

jimmyblue

iTrader: (11)

It is, in stock config, but that doesn't suffice for many
people with non-stock exhaust plumbing.

jimmyblue

iTrader: (11)

OP, you might want to try one pass "learned real good"
and then do another pull-battery reset and see how
that affects things, back to back.

Fuel learning will never put you leaner than the base
tune commands, but can enrich big time. A bad sensor
on my van is pushing >20% LTFT and 50% STFTs in
today's logs. So if your setup is naturally overfueled
(at WOT) it will stay so regardless of learning, and if
underfueled at the little end you may compound WOT
enrichment if learning proceeds to its conclusion, but
get that out of the way if you reset it.

RockinWs6

If the fuel trims are negative it will not take away fuel at WOT, BUT if they are positive it will ADD that amount at WOT so the engine doesn't run lean. This is true for the factory tune, custom tune could be anything.......

joecar

So you want to run MAF-less...? Has your VE been corrected...? If not then you're better off running the 1/4 mile with the MAF.

( and, no, you don't have to disconnect the battery to unplug or replug the MAF )

RonSSNova

iTrader: (3)

Sorry, but this is just bad info.
As soon as your foot goes to the floor, the car enters Power Enrichment mode and is in open loop.
Most calibrations I've looked at have the MAF taking over above 4000 rpm. Trucks may be different.
If the OP simply unhooked the MAF and goes racing, the car will revert to running on the VE table. It will reset trims after driving based on the calibration of the VE table. Trims could be anywhere......

So if the car happens to suddenly go faster, it's pure luck.

Ron

01ssreda4

iTrader: (96)

How and when power enrichment comes in is completely up to the tuner.