So i just put a turbo on my silverado, and boy is it a blast, but ive got a small bug in the tune and im not sure what to do to get rid of it. I first noticed it after i got it all installed and it seemed kinda random and i couldnt quite pin it down. After tracking it down for a while I finally figured out when it happens but I still dont know why. The truck wants to "surge" or "buck" and i finally noticed that the spark was very erratic when it would do this. It starts at 2000 rpm, and doesnt seem to do it much below. It also seems to be when the vaccum is running somewhere in the range of 0 to -7in. I can feel it in all the gears, but its more pronounced at highway speeds with the converter locked. At highway speeds just cruising around -10 vacuum or more it wont do anything, but get to a hill and the vacuum drops and it starts to buck and shake.

I was thinking maybe it had something to do with the IATs being pretty high, but i still dont see why that would make the spark bounce around like it does.

I included a short tune where i got it do act up and the tune i was running at the time. I also included a screencap to show what its doing and where to find it in the log.

Thanks for any help, Im new to this tuning thing and trying to learn it on my own.

 

what do you have done with you truck need info bout ur truck...

 

good point forgot about that........doh

99 silverado 1500 5.3l stock internally besides ls6 valvesprings.
Just got done installing an sts remote mount kit.
2 bar map sensor with hp tuners 2 bar sd os.
72lb injectors, stock injectors resized by fuel injector connection.
upgraded fuel pump to highflowperformance fuel pump. not sure about the specs on the fuel pump because it came with the turbo kit when i bought it.
innovative lc-1 wideband.

Im pretty sure thats all the important things, unless ive completely forgotten something.

 

Its too lean. Try changing your PE enable to like 300 rpms.

Edit: Actually there are a few things I would change about your PE settings, and I haven't looked elsewhere yet. That 'Delay RPM' setting would be a good place to start, though.

 

is that graph on idel or u reving it up cuz if thats idel,1300 is high! but listen to smoke show,hes been right bout everything he had told me so far...

 

What converter do you have? A smaller converter can sometimes simulate a spark knock. Just another thought.