Timing Flutter on part throttle to WOT from stop

[taylorjones_11]

Hey guys new to the forum, and have had HP Tuners since December of last year. I've been working on speed density here lately and have a few strange issues that I can't figure out what's going on.

To start off, I installed this cam two years ago and have had the truck tuned "Professionally" twice by different people and was not happy with the results. Second tune was livable and is what I'm using as my baseline right now, but the more I dig into it the more issues I found so I've been trying to start from scratch mostly.

I'm working on Speed Density currently, but I have an issue with timing dips around 2400 rpm when I'm on the throttle fairly hard to wide open. I'm not sure what is causing it, I have my PID's logging knock retard as well as torque management but I don't see anything being pulled at the moment that I'm having the issue. I'll upload my tune file and my scan file so there's a good idea of what's going on.

The best example I can give you in the log is at 9:58:12 timecode. I tried to replicate it a few times, but that was the most dramatic

Also to hijack my own thread, if any of you have any suggestions on how to make the VE table smoother please let me know. I tend to be super lean at idle until it warms up completely. I've seen mixed ideas about changing cranking VE table and am not sure if that would help. It's really quite strange. When I first crank the truck it idles at 14.7 for about 20 seconds or so, but then quickly creeps up to full lean on the gauge. I've tried adjusting this on the VE table, but it screws up everything once the truck is warm. Correct me if I'm wrong, but is this what the OLFA table is for? if so, how does it correct things once I'm getting on the throttle? While the truck is warming up I can't keep a steady rpm currently, RPMS jump all over the place if say I use 20 percent throttle pulling out of the driveway, it want's to lunge and jerk forward. Once warm though it all goes away.

Any help will be appreciated!


SD Step 27.hpt
log 27 SD.hpl

[5FDP]

Burst knock could be pulling timing, that is a different table you can log. Most just disable it to stop it from yanking timing when you mash the throttle. You can max out the ECT limits ETC TPS max table in torque mngt too.

You can use the open loop EQ ratio if you want the fueling to be richer while the engine is cold. After 110-120 degree coolant temp is when it should start leaning out towards 1.00 (stoich).

When you are tuning the VE with your wideband are putting the truck into open loop with no short term or long term fuel trims??

[taylorjones_11]

I started with no fuel trims, I've been working them back in though lately because I have the VE table close, I also mainly put short term back in so that it would take care of the lean spikes at startup. IT's really strange. I'll have to log it cold and upload it.

Do you happen to have an explanation for why it would start up at stoic and then lean out quickly after that even though commanded AFR is richer than stoic because of the OLFA table?

I'll give the burst knock a shot. A while back I installed the cat back muffler myself, and have noticed random knock occasionally and I'm wondering if it's causing false knock. I know you can't always hear it knock, but there are areas on my table that pull 4 degree's of timing and I have already backed timing way down as you can see in the table. My original tune had 25 degrees of timing at WOT in upper rpms now I'm running 19 and running into some knock retard.

[taylorjones_11]

removing burst knock seems to have fixed the timing flutter that I was having an issue with.

Thank you for your suggestion on that, do you have any more tips you can hit me with, still relatively new at this.