Predator

[Mike M]

Using the predator and under "Modify Tune" does anyone know the correlation of hash marks on the screen? For example moving it one hash mark to the left (RICHER) at 5-7000 rpm will have how much of an effect to the A/F?

The same for the Timing screen.

[HwyCruiser]

Mike, it's been awhile since I played around in that part of the tune, but IIRC its -40% to +20% to the spark advance and -20% to +40% to the base fuel tables for the base tune in those rpm ranges.

I've never touched them though. Hit Dave L. up with an email, he'll have the exact figures and work with you on what your looking for. Trying to take advantage of 100 octane gas? Dave has that covered.

[Mike M]

I changed my pulley and until I find a tuner in AZ I want to fatten up the mixture. I would think moving it to the rich side should work and I would rather error on the side of too much fuel. I am a little afraid to really get on it.
With the 9 PSI pulley my A/F was perfect and flat. Withe the 12PSI I know I will probably be lean.

[HwyCruiser]

While you're in a pinch you could get a wideband o2sensor / gauge so you can tell where your a/f is at and tweak it from there. I saw your other post about the fuel sensor code. Did this happen after you went to the bigger pulley?

[Mike M]

Yes the code came on today and I changed the pulley about 3-4 days ago.

[JMan]

Yes the code came on today and I changed the pulley about 3-4 days ago.

I believe if fuel starvation was an issue, you would have gotten a code for excessive fuel pump duty cycle and not a fuel rail pressure code. It also may take two contiguous drive cycles with the conditions present to set full blown codes. The pump duty cycle is governed by the rail pressure. Low rail pressure would have driven the pump module to increase the duty cycle until it hit the criteria for setting the duty cycle code. What's the exact definition of the code you have and does your code reader show manufacturer specific codes (e.g. P1xxx as opposed to just generic P0xxx.)? If you know someone with a full blown scan tool, it might be wise to have them check for codes. Your code reader may only be giving you half the story! Go easy on her until you know what's going on, for sure.

Best luck,

J

[Mike M]

I have a OTC Genisys back in NJ, but I am out here in AZ and all I have is my Predator which only does the generic. I cleared it and will drive for a few days to see if it comes back on. I want to richen it up with my Predator but It's a little like black magic when all you have is a scale that says "Rich-------"Lean" and no feedback. The wide O2 sensor gauge may not be a bad idea.