Any idea why I have tip-in hesitation? w/scan

Hey guys, my Silverado (in sig) has always had about a half-a-second hesitation whenever I hit the throttle harshly. I say hesitation, but actually it falls on it's face a little and then the rpm shoots up as it should.
My afr's are pretty well dialed in across the board (olsd), and it doesn't just do it from idle, for example it can be humming along at 3,000 rpm and then you whack the throttle, and it falls asleep for a split second before it roars to life.

Sorry, I don't have my wideband hooked up in this scan.

bump

any time i ever had tip in hesitation i was to lean,but every vehicle has its quirks to figure out.

I noticed that not all of your torque management has been disabled. max torque is at 350 - max this table out. I don't know if this is your problem or not but I always max this table.

holy crap! I just noticed that your power enrichment and boost enrichment all are set to 1.00! this is basically no power enrichment! This thing has a turbo on it? these tables need set up. Throttle is right also - most of the time if you have poor tip in throttle response the ve table is lean in that area or you need to work with transient fueling.

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Originally Posted by 68Camaro

holy crap! I just noticed that your power enrichment and boost enrichment all are set to 1.00! this is basically no power enrichment! This thing has a turbo on it? these tables need set up. Throttle is right also - most of the time if you have poor tip in throttle response the ve table is lean in that area or you need to work with transient fueling.

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Yeah I know, I couldn't believe it the 1st time I saw that either. (I bought already built, tuned, broke-in,) The afr looks pretty good across the board (14.7 light throttle to 10.9 at high boost levels. I have contemplated fixing all of that, and doing it right, but other than that tip-in hesitation, it runs perfect. I've owned it for a year and a half and it can handle stop n go traffic and it runs in the 10's without any issues.
So I guess I haven't had much motivation to fix the tune. I guess I'll mess with the transient fueling and tq mngmnt, and if that doesn't help, then i'll fix my VE, PE & BE.

Thank you for the help

Even though the fueling is technically where it you want it at the end of the day. With the enrichment tables being 1.00 and wot being at 10.9 the ve table is probably butchered. So even though you're fueling is where you want it, the car isn't getting an accurate representation of the actual airflow going into the motor. I'd imagine that if you properly redid it it would drive a hell of a lot better, and probably make more power as well.

Thanks for the input gentlemen.

Well last weekend I finally went through all of your suggestions, and surprisingly, nothing seemed to make the hesitation any worse or better.
-I maxed out the tq management.
-I basically started from ground zero with PE, BE, and adjusted VE appropriately for afrs to match commanded.
-I also messed with transient fueling.

I will say that I have never dealt with transient fueling before, so I don't know that I can write that one off just yet. I only messed with the "fuel boiling time..." and "wall to impact factor" tables. I tried increasing the entire tables in 10% increments and then decreasing, but nothing seemed to have an affect.
Is there something in particular that you would suggest I should be doing with transient fueling?

Got a recent log with the hesitation?
What injectors? and is the data correct for them?

http://www.hptuners.com/forum/showth...A-how-to-guide

that will help you a lot with understanding transient fueling.

Fixed it! Just needed to increase the Wall to impact Factor table a bit more. Yeah, that how-to was very informative (some of it was over my head lol).

Thanks so much for the help guys!