that is weird. it looks like your power spiked, then your rpms dropped few, then you kept on going. Did the rpms drop for a second during the run?n Or did the truck sputter?

 

he didnt say he felt it, but after looking at the sheet, he said it was like a hesitation. I dont know why it would spike like that. Back to my air fuel #'s what are mine. Are they leaning more towards the lean or rich side? I dont really know how to read these sheets that well. Im still learning. Thanks, Shane

 

Like Dan03 said:

I think all of our trucks start out lean from a stand still, then richen up. 11-12 A/F is a pretty good range. Looks like you stayed above that for quite awhile and finally dropped to the 12's w/ higher RPMS. Either you are not getting fuel or need a better tune...or you are having issues with torque lockup

 

That's what jdm said the problem was with the first dyno pull. The torque converter was not locking up at the right time...
Now this time it is doing something similar. Except the decline, it is spiking or looping. Have you ever seen a loop before on a dyno? Would you suggest it's the converter not locking up? It is a new stock converter. What exactly is going on during a dyno run. You want it in 3rd gear and you want to be able to hit it, (have the torqe converter lock up, and also not down shift) then hold it till 5400 or so... What exactly is going on or supposed to be going on during a dyno run?
Thanks, Shane

 

Yes. Mine did the same thing on the 3-4 shift at low RPM's due to the torque converter not locking up right with the chip and with the FTVB, had the chip reburned and no more loop.

 

Thanks man, the guy at the dyno suggested it was the chip. I contacted JDM first thing, and they didnt think it was the chip. They thought it was the dyno. I may try either a run on the street side, or a 3/4th throttle run without the chip. Is that safe? And will that then tell me if it is the chip or not? Do you think the converter is not responding right to the chip?
Shane

 

ive seen this before. someone was dynoing a stock f150 and couldnt make a full run due to the speed limiter. it made a very similar dyno sheet. food for thought

 

Any clue what the fix was? Also why am I not feeling a spike, or a hesitation on the street?
thanks, Shane