Bad30th

iTrader: (13)

I've read and read on P0101, but I'm still stumped and could use some advice.

Ever since I put my blower/heads on I have had a light load surging problem when the torque converter locks up, it was throwing P0101 at cruise so I opened the MAP window on the code.

Now the code isn't being thrown but the cruise drivability still sucks. I can't cruise with the TC locked up at a light throttle, low RPM cruise without bucking and surging. It clears up at about 15-20% throttle or higher RPM.

I have a stock/screened (powdercoated) MAF on the car.

I have seen some people suggest multiplying the (entire ?) MAF table by 1.08 and see if it helps, but I think that may do more harm than good...

Fueling is pretty much right on, LTRIMS close to 0.

Any ideas ? Oh, and I do have HPTuners.

Thanks !
Rob (Bad30th)

Dixit

iTrader: (1)

That usually is because your MAF calibration is off more than what the P0101 table is. That table shows the maximum swings it can take before the computer will throw a code. That means your MAF calibration is off from your VE table.

If you are saying that your LTRIMs are 0, I take it you mean they are 0 when in SD mode, if so, then just calibrate your MAF. Dont do a flat out multiplication of the MAF table, do it right by calibrating your MAF to the VE table. That way the LTRIMs stay close to 0 even after you put the car back to MAF mode.

The reason for the surging is that your PCM kicked you into SDmode. If you have that code on, you are automatically thrown into SDmode, that is why you get the slight surging effect at times. This kind of tells me your VE table is not in line with the 0 to -4 standards most use around here.

Dixit

Bad30th

iTrader: (13)

Thanks for the reply. Actually the code isn't being thrown anymore since I set minMAP=0 maxMAP=100 on the P0101 code.

The surging occurs when the car is in normal operation (not SD mode).

I'm guessing (and it feels like) the MAF just needs to be recalibrated ?

Should I just go through the logging/"MAF table building" procedure now that the heads/blower are on (since VE is pretty close ) ?

Thanks for the help guys.

Rob (Bad30th)

Dixit

iTrader: (1)

Well you pretty much disabled the code by doing the change on the P0101 code. I would return that back to normal. Put the car in SD mode, get your VE trims within 0 to -4 if you can. If you can, then most suggest -5 to +5. If you can get the Trims sucessfully to those numbers, then use the MAF calibration spreadsheets that 3-4 people have made in this forum. Its in the sticky. Then just make a few trips logging with the appropriate info, and get the MAF table calibrated so that the LTRIMs stay within the above range.

Dixit

Bad30th

iTrader: (13)

Thanks for the info, I figured something needed to be done to compensate for the new mods but wasn't sure exactly what/how.

Is it common for the MAF table to need to be touched when induction/engine changes are made if the MAF is still stock ?

I'm gathering that the MAF curve is really a representation of dynamic airflow rather than a 'configured to the MAF on the car'-kind-of-table. Am I correct there ? (*little light bulbs going on above my head*)... In otherwords, the reason a stock LS1 MAF table is different than a LS6 MAF table (or others) isn't because the curve is designed for the electronics in that MAF but rather for the airflow characteristics of that MAF (in its stock application) ? (so a stock LS1 MAF may have a much different curve in a stock car vs. a heads/cam car vs. an FI car ?)

Cheers,
Rob (Bad30th)

ntimid8r

iTrader: (5)

Hey Rob, I've been having the same issue ever since going up to Van Nuys. Ed took a look at my bin file and saw the VE calculations are altered ( I have no idea about that). Anyway Ed was coming over tonight and putting the VE table back to stock. He say's that's how his is set and he doesn't experience the hesitations at cruise speed.

I haven't figured out this whole tuning thing, but from what I've read on the boards, basically no need to mess with the VE table. Just my .02.

Good luck,
--Rich

Bad30th

iTrader: (13)

My VE table is stock except for where it was corrected for fueling being off (from Strictly) to bring trimming back to 0 (or close to 0). The hesitation at low load cruise in TCC lockup was present before then though (ever since the 71cc 5.7L heads install, which I'm sure changed the airflow characteristcs a lot from the milled 5.3L heads).

I have a feeling it has more to do with the MAF table than the VE table, because as I recall when the P0101 would trip and it went to SD mode there was much less surging. I'll do some testing this weekend.

Cheers,
Rob

MeentSS02

iTrader: (11)

Man, if I were you, I'd get a wideband in the mix and tune it in SD. If your MAF and VE tables aren't in agreement, you are gonna get a car that runs like ****.

With just bolt-ons, my VE table is quite different from how it was stock. Then again, I got it in line with a wideband. Took me all of an hour of driving.