SgtB

Sounds like a dead coil pack or a fried spark plug. Unplug the connector from each coil pack one at a time and if one doesn't make it run worse, remove it. Swap that one with another cylinder's pack and see if the problem moves with it. If it does, replace the pack. If it doesn't, check the spark plug. If the plug's good start looking at wiring and ecu problems.

speedjunky01

Sounds like its swap time!

Billman250

Misfire. very easy to find. Very likely bad coil pack.

CKit

On a turbo'd car, I wouldn't be surprised to find a degenerated plug. Most aftermarket turbo setups run copper plugs which need replacing often. But for $1.50 each, it's not that big of a deal. I'd start there.

S2oooNvegas

Check/replace all 4 of the plugs, while at it do a leakdown on all 4 cyls. Doesnt take long. Then youll know if your engine is fine. Then you can move forward to coils or injectors.

speedjunky01

yeah do what he said

Throw parts at it without knowing the actual problem and hope that you don't waist a few hundred dollars.

S2oooNvegas

??? who said throw parts at it?

Dont try and put words in my mouth smart guy. Youll just end up looking like an ass.

SgtB

Changing the plugs is throwing money at it. Doing a leak down test requires more work than a coil swap.

Step 1: CHECK THE COILS. I can almost guarantee it's a dead coil pack. I've seen it quite a few times.

S2oooNvegas

Guess your right on that sgt, but... thats the cheapest part. And unless they are OEM plugs i dont trust em. Ive seen every kind of junk plug you can imagine in s2ks with every type of issue you can imagine. Cracked, seperated etc. S2k is hard on plugs. And its the cheapest thing that needs to be 100% in the system during diagnosis.
Never seen a coil go bad... NEVER ONCE in the last decade.
Seen only 2 injectors go bad.
Most thing ive seen cause misfires... bad valve guides.
2nd to that damaged or bad plugs.
Old plugs wont even misfire if they are intact. Seen em with almost no electrode left... and firing perfect.

Leakdown is the smartest thing to do cause it just takes minutes and lets you know your engine has its integrity.
Ive seen countless clueless techs chasing a misfire on all types of cars, changing coils and moving injectors around... only for it to be a mechanical issue.
So the smart way to diag... KISS.... verify that the engine is mechanically sound BEFORE you go assuming ANYTHING.
Thats all im trying to say.
But that IS the issue with forums these days. You get 9 million "opinions" and very little stuff actually backed up by experience. every guy that has changed his own oil thinks hes an s2k specialist now. lol

Slows2k

https://www.s2ki.com/s2000/topic/867...ave-a-misfire/

In 12 years I've put 1 coil in confirmed to cause a single cylinder misfire.