sweet-94z28

iTrader: (30)

I've done a bunch of searching and I can't seem to figure out what would cause this....

I have a 2004 Corvette with MS3 cam, PRC Stage 2.5 ported LS6 Heads, LS6 intake, full exhaust. Well, when you floor the car, the throttle position goes directly to 100%, but the car still holds a 14.7 AFR or so for about a second after being at full throttle (this happens at all RPMs as well, no matter whether 1500 or 5000). You can physically feel the car pull 3 times harder once the enrichment enters and the AFR goes to 12.8. I have a wideband as well and it can be seen on there as well.

I made some changes to the tune last night with hopes they would help, but they did not. I can post up a tune and a log after work, but what I'm describing is exactly what it is doing. O2 will continue oscillation (100-900 mv) for about 1 second after throttle position is 100%. Power Enrichment settings are:

Power Enrichment Enable MAP: 70 kPa
MAP Hysteresis: 5 KPA
Delay RPM: 100
RPM Hysteresis: 10
Enable Torque: 100%
Torque Hysteresis: 15%

My throttle position enable is even lowered to 45% from 1K RPM to 3.8K RPM, then one 33% block, and then 22% after that.

Enrichment rate is 1.7500 (but 1.000-4.000 all should enrich at an instant rate correct???). I tried 1, 2 , 3, and 4 with no change.....




I'm just lost. Everything is there and Power Enrichment is still delayed. I also have an 04 GTO with the same power enrichment setting and it instantly goes into PE.

outkast6991

iTrader: (34)

does hp tuners have an PE delay table? efi live does it's table B3609

sweet-94z28

iTrader: (30)

Its just a commanded rate. .0001 being slowest enrichment and 1 supposed to be instant. Applies to all RPMs. I have used a little bit of delayed PE in Speed Density tunes before for cars that were a fuzz fat on the transient fueling.

BLK02WS6

iTrader: (2)

There should be a delay table as well as the rate...

sweet-94z28

iTrader: (30)

There is not in HPTuners unless I'm completely missing something. There is a pedal position table, then MAP enable, and RPM delay (below that RPM, PE is delayed for the time specified delay rate in the scalar).

sweet-94z28

iTrader: (30)

Still does it with the 50% torque enable. I have all torque management tables set at 640 Ft-Lbs so maybe that has something to do with it.....

BLK02WS6

iTrader: (2)

Guess that is one more reason to go on my growing list of why EFILive is better than HPTuners... The table I am talking about is exactly your problem - I am attaching a screen shot of the table from a 2004 vette - you can see it is set at 1 second...

sweet-94z28

iTrader: (30)

When I break the threshold of PE TPS Enable, I want to be fully enriched at that point in time. A rate of 1.000 in the HPTuners scalar means instant enrichment once parameters are met. I'm measuring a rate of ~150-170 ms reaction time on my dad's 2005 chevy truck with the 1.0 enrichment rate. 1 second seems like it would be a little too much time to enable enrichment IMO, especially with the MS3 cam that pushes a lot of air through the motor in a nearly instantaneous throttle movement.

I ended up finding the issue though. I got a P1637 on the way home from work last night for an Generator L Circuit failure code. Alternator never died or acted up though. Well, I wanted to make sure all wires were good so I popped the computer out and tested continuity in the wiring harness, checked out good....

So I was putting the PCM back in and found a vacuum line just dangling with nothing on it. So I fixed that and so far everything has been good. I get ~200 ms reaction time, but I would call that normal with this cam. I don't feel a stumble at all anymore at low RPMs either.

BLK02WS6

iTrader: (2)

Glad you figured it out! Just so you know - the table I posted was a stock table - we always change it from 1 second to bring PE in instantly (when the other parameters are met)... I have always hated the differences in table labeling between software programs - makes things confusing in an environment like this.