The 06+ AP2's do have static fuel pressure at around 60 PSI, and there is no fuel return line.

It would be very weird for LTFT and STFT to follow each other. If your STFT is consistently positive, then LTFT will be incremented until STFT averages about 0. Total fuel trim = LTFT + STFT.

 

Sorry i meant the values are +-5-6% on either side.

 

so if i have full bolt ons on my 2005 ap2 s2000, the vafc will not be able to add fuel to parts in the rpm range where im running too lean?

 

Correct. A VAFC tricks the ECU by altering the MAP signal. So if the ECU thinks it's reading above atmospheric pressure, then it freaks out. This is why most piggy backs aren't that great.

Why does it do this anyways? I'm sure the MAP can handle above atmospheric.

 

The OEM MAP is good up to 10 PSI. However, the stock ECU should never see boost on a stock car. The fuel and timing maps aren't built to handle it. Hence the freaking out.

 

GRRRR I should have known that. It's one of those moment were you feel stupid.

 

The guy I bought my VAFC from has his MAP loaded already..Whats going to happen when I just plug this bad boy in?

 

Anybody know?

 

When you hook up the VAFC, and turn the car on, the VAFC will probably still have the previous owner's settings. However, you should go through the setup before you start the car. If you are sure it was in an S2000 last, then you can just zero out the fuel adjustments for part and full throttle and set VTEC back to 6K. If it might have been in something other than an S2000, then you should do a full reset of all settings.

 

It was on an S, and he only tuned at WOT and set the vtec at 5700. We basically have the same mods.