Noticeable lag at 4K

[jimprw]

Has anyone else experienced a noticable, but not extreme, lag when accelerating normally between 4000 and 4300 RPM? It isn't noticable under aggressive acceleration, but just cruising around town when I hit about 4k I feel a slight bog or lag which disappears after about 4300. Car runs just fine in general and I thought maybe after it was broken in this slight burp would disappear, but after 900 miles it's still there.

I don't think it is electrical and the engine does not seem to misfire at any point, but it feels kind of like the slight pull back you feel when you turn on the air conditioner. I was wondering maybe if it wasn't related to how the runners are set up or something else in the induction system where at around 4K something somewhere switches over to something else for operating at the higher RPM range.

Or...maybe something related to skip shift??? Doesn't that quirky deal kick in somehow around 4K?

Oh, and speaking of the air conditioner, it is 96 here today and I can definitely feel the drag on the engine when AC is on when accelerating. Just wondering if anyone else has experienced either of these issues.

 

[ArizonaBOSS]

I believe that's right about the range where the cam profiles switch over.

 

[STIG302]

I've been running the A/C every time, but haven't noticed. I'll be looking for it, next time.

 

[DigiCowboy]

Seems to me that the AC compressor cuts out on hard acceleration.

 

[rtmc67shelby]

I too see the ac compressor cutting out on hard acceleration.

 

[BossMan]

That is funny that you mentioned that. I have noticed a slight hesitation too but wasn't paying attention to the rpm's. At first I thought it was maybe a spark plug misfire. I do not feel any pulsing at cruising speeds.

 

[BossJockey]

I believe that's right about the range where the cam profiles switch over.

I think this is what we are feeling.

 

[Fat Boss]

Haven't noticed that. I'll keep an eye out for it. What I did notice is the "non-linear" engine braking. It seems to change how much engine braking you get as the RPM's decrease.