A note to add, when throttle is partially pushed in it seems to pull hard through the low rpm’s but if I floor it (WOT) that’s where the issue exists.

 

Clutch ruled out! And it didn't cost you anything but your time.

 

Did a compression test, highest was 210 and lowest was 200 tested each cylinder twice.

 

I think those compression numbers are fine. Compression testers vary in accuracy, so you are looking for consistency between the numbers rather than an absolute number. 200+ should be fine.

What year is your car....is it drive by wire? Your comment about the power seeming to be good when partial throttle, but then power going away at full throttle is a big hint - you should have started with that! :-) Assuming you car is drive by wire, maybe something going on with the throttle pedal position sensor or with the throttle actuator.

 

it’s a 2000 (rhd not sure if that changes anything)

 

Any progress the past week?

New to you cars can be a puzzle. Who knows what's happened in the past 20 years?

Grab the Service Manual and check the throttle cable adjustments and smoothness. And maybe the VTEC seals (grasping at straws here).

-- Chuck

 

I would do internet searches on these symptoms, but search generically, not S specific.

So don't use keywords S2000, nor Honda, nor vtec. Exclude the idea of it works fine in vtec, etc.

I'm thinking whatever this odd issue is, its not S specific. Gut says it could happen to any engine.

So search on something like:

acceleration loss, normal acceleration partial throttle, but sluggish wot, but only at lower rpm range. high rpm acceleration normal

Keep digging into results returned. My bet is somewhere in there, in some other forum for some other car, will be your answer.

I tired it, and came up with stuff like air filter, maf sensor, etc. Which seem lame but easy enough to check, clean, etc. But also an interesting one, spark plugs. Story about cracked insulator that only showed at lower rpm high load, wot etc. Somehow at higher rpm it was masked. Again, this was on a different forum, for some totally unrelated vehicle. But that is kinda place where I think you'll find your answer.

Broken insulator story sounds contrary to intuition, but it was issue for someone. My guess is your solution will be something like this, that you'll find buried somewhere in some forum. Now you just gotta dig in to research.

 

Apologies for the lack of responses; I’ve been busy with work. Finally, I had some free time today and swapped the map sensor, hoping that would fix the issue. It did not; the car does feel somewhat smoother, but my issue still persists. I also sprayed carb cleaner around the bay to check for vacuum leaks, but nothing there either. A note to add, I have already replaced vtec solenoid gaskets. I did find a leak from my Timing chain tensioner(TCT) and rear of valve cover. Will be ordering new gaskets and TCT maybe one of those is my culprit.
Can see the oil spilling from the bottom of tct and bolt head

This was after I wiped it down before a 10 minute test drive

 

sounds like the car is running overly rich, that will kill performance as the car runs rich in factory form when perfect. Perhaps the two sooty plugs are an indicator for the rich running cylinder. The fuel injectors may not be spraying properly causing a rich condition with unburned fuel. I would run a bottle of Redline Fuel system cleaner, cheap and easy, and it is one of the few products that works. A valve adjustment / check would be a good start as well. check the spark pug gaps, make sure they are within spec (1.3mm or less)

 

Which plugs? Spark plug gap is 1.0mm to 1.1mm. (That's the "11" suffix in the part number.) . I have a shed full of gasoline powered lawn equipment and when I have trouble with how the engine on any of them runs resetting the gap (or a new plug) will almost always fix it. (Still grasping at straws here...)

-- Chuck