Hesitation, detonation, need input

[97stscaddy]

Cars been doing this off an on for a few months but it would do it once maybe then it was fine. Now it has started doing this fairly often. When I hit the gas to try and pass someone, the transmission kicks down just fine, but the car doesn't go for a few seconds. Every now and then it does this from a stop as well, but it does it more often when the car is already rolling. Also sounds like there is some slight detonation going on right when I hit the gas, which makes sense because it could be leaning out when the throttle plate opens up. Which would cause the ECM to knock back the ignition timing to prevent the damage to the engine.

The question I have is why is it doing this? No CEL yet, so no codes to be read.
Any ideas?

 

[camthman]

how many miles? coil packs? VC gasket? tuneup?

 

[NYC LS8]

Cheap gas?

 

[97stscaddy]

No coil issues for the time being. Did the VCGs last year. Just turned 64500 on the ticker. Use fuel system cleaner once every 3 months or so.

Dunno about the gas, I always run Shell or Amoco 93. Sometimes I go to Exxon if I don't think I have enough to get to one of the others, but its not my first choice.

 

[NateRW21]

I'd still be looking at coils. You could swap them from side to side and then go beat the hell out of it... see if anything happens.

 

[97stscaddy]

Exactly why would swapping coils help?

Not to sound rude or anything, but if you know some reason as to why any coil would work better on one side of the engine than the other, please do tell.

I am kind of overdue for the next coil to fail though. I've changed 4 or 5, (lost count) and they usually are about 1.5 - 2 months apart. I think its been 3 since the last one.

 

[NateRW21]

I'm not saying it will help eliminate the problem... but it might trigger a CEL... give you a bit more to go on.

 

[97stscaddy]

Bah, that's too much of a pain in the ass for something that I don't even know if it'll change anything.

Drove it around tonight and tried to figure out exactly what is going on when it does this. Couldn't make it happen often enough to find any pattern or any particular vehicle or engine speed where it does it most often.
I do get a nice loud "CLICK" when I open the throttle more than about 50% from idle. Same with rolling slowly up to about 1200 rpm in first gear, except it only does it at WOT when rolling.

 

[NateRW21]

hmmm

 

[PatrickSimmons]

I'd have to say coils all the way. Best thing to do is change them all at once.