nash8503

I have a '98 motor with 232/236 comp cam, stage 2 heads, long tube headers, z06 intake, 78 mm TB, Granatelli MAF.

Problem is the car runs strong under part throttle accelerations but as soon as I go to WOT it sputters and looses power. My wide band O2 shows 12.8 A/F ratio during WOT and timing is around 15 - 17 degrees.

Any ideas out there????
LS1 Bimmer

TNormZ28

iTrader: (9)

More info. A4? M6? Tuned? First, ditch the Granatelli.

nash8503

[QUOTE=TNorman]More info. A4? M6? Tuned? First, ditch the Granatelli.[/QUOTE

M6, 28.8 injectors. I have modified my IFR so that my LTFT is around zero. After this I was running WOT A/F around 10.5 so I backed fuel out of the WOT table and the AF is right around 12.8.

I thought about ditching the Granatelli but it didn't seem to make sense since my A/F ratio is right where I think it should. But I'm willing to try anything so I will switch back to my stock MAF today.

thanks - mike

TNormZ28

iTrader: (9)

12.8? Try 13.5:1 if you are N/A. Check the simple things like plugs, pins in the connectors (make sure they are tight). Any KR?

nash8503

I'll try new plugs. Any plug suggestions for my setup?

thanks - ike

TAQuickness

iTrader: (28)

N/A - NGK TR55's gapped 0.050" - 0.060". I gap mine to 0.055".

nash8503

OK I changed back to the stock MAF and problem did not change. I recorded AF for several WOT runs. What is happening is the AF starts around 14.7 then drops to about 13. It stays at 13 for a short time and then it dumps down to as low as 10 it eventually recovers and fluctuates all over the place between 10 and 16. The basic pattern is the same for all runs but when and how unstable the AF becomes changes from run to run.

Another thing I have noticed is my scan tool never shows open loop? I go into cell 22 which I think is the PE cell but I am still in closed loop. I thought for WOT it is supposed to be open loop?

Any suggestions?