Power loss abowe 60% throttle

[frebo]

Hi,
I have a 2000 med Corvette with automatic transmission that loose power when I exceed 60% TPS. When I use the scanner when I drive I can see that the Inj. Pulse width drops about 40% when it happends, but I do not get any DTC's .
Do anyone experienced the same problem and know what can cause this?

[mowton]

Go through your DTC's and Make sure that DTC 0068, 0121, 0300, 1514/1515 etc are not No Reported. Does the chenck Engine light flash? What does the TPS% do when this happens, how about the timing. Do you have to turn-off and restart the car to het the power back?

Sounds like Reduced Engine Power.....Post a tune and log please along with the mods.

Ed M

[frebo]

Hi,
There is no DTC reported as far as I can see. The check engine ligt do not flash. The TPS is working fine, the timing is also looks right, The car is now at the dyno, the pull that is on the log now it puts out 246 HP. I added log and tune file.

[frebo]

Hi,

Here is the logg and tune files

[mowton]

Your Fuel trims are over excessive at +15 to 25% and the PCM is carrying an extra 15% of fueling going into Power Enrichment (WOT) as protection against lean condition. Also you are in CL (Closed Loop) Fault which does say you have a DTC failure most likely excessive lean like P0171/P0174.

Your O2 voltages at .020 mv also verifies you are running way lean.

Ed M

[frebo]

That is thru, but can you see what can be the problem? it is strange that it suddanly starts to run lean one day? I also see in the logg that max duty cycle for the injectors at 6000 rpm is 60,4%, isn't that a bit low? And why does the LTFT stock in 15,6% steady above 3000 rpm?

[frebo]

After change of Air mass sensor we are back in buisness. now it puts out 356 HP and 794 Nm. But we tried to change the igniton table to get some more advance, but it seems that it pulls the advance down. Do you have any ideas of why it do this?

[mowton]

So you had DTC's then.....You are not logging enough needed channels to be able to analyze the log. There is no cylinder airmass, MAF Hz, Dynamic Airmass, wideband, knock retard, Fuel Trim Cell etc...Add these and show another pull.

High Octane table is pretty high and plateaued and worse, the Low OCtane table matches the High Octane which means you have no knock retard function...bad recipie man....

Ed M