light throttle load surging... P0101 ? MAF table ?
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)
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
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
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)
Last edited by Bad30th; Aug 5, 2005 at 10:19 AM.
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
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
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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.
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