i own a 2001 lightning, just did a pulley upgrade and a couple of other things..its making 14psi as of now. i took it 2 a dyno shop and had them tune it and now it is starting to pop when it downshifts and if i take it above 100 it starts popping alot, i already regapped the plugs and i put nothing but 93 octane in it...is there anyway to make this stop? putting a fuel additive maybe to up the octane add timing? remove timing? idk but it runs good and all but the detonation makes me worry that eventually my motor is gonna go...so if anyone has any answers or suggestions, plz let me know! thanks,
cj

 

" i took it 2 a dyno shop and had them tune it and now it is starting to pop"

Redo this step. Maybe a shop that can tune it right. Coastal can do eet.

 

Right away my mind says its not in the tune...

Back up even further...
Check/change fuel filter, check/change plugs etc.. etc..
What plugs are you running?

Lets just say for the sake of arguing... if it is in the tune, what a/f ratio is the tune set at? What timing is it for? What numbers are you putting down.. (I know right away you are saying, what does that matter, but it does) What are all of your mods, and did they tune for each and everyone of them?

 

make sure ur intercooler pump is working. had to replace mine due to detonation. gets hot and cpu pulls timing and fuel causing detonation

 

In theory the ecu will actually add fuel if it senses hot. Your correct on pulling the timing. And last I checked I would describe detonation as a pop. When does it happen under full throttle? When it shifts? When you let off the gas?

 

only at wot and when it downshifts a gear or 2 depending on speed thats the only time....

 

Any codes being thrown?

 

nope none....

 

I would tend to think if it was a tune, there would be some codes being thrown... my 2¢

 

you dont have a knock sensor you can look at?