My wife drove the s2000 to my office yesterday to pick me up so we could drive to an appointment together. Without shutting off the car, she moved to the passenger seat, so I was driving. I hadn't moved 100 feet - still in the parking lot - when suddenly the exhaust note sounded a bit off, then I felt a pronounced shudder in the engine, like it was missing. I immediately coasted to a stop, then a few seconds later the CEL started flashing.

I limped it into an adjacent parking space, and we drove my Cayman to our appointment instead. (It's not every day that your Honda breaks down and you have to take the Porsche as a backup, lol.) After our appointment I came back armed with a car buddy, some tools, and a code scanner. We pulled codes p1399 (general misfire) and p0303 (misfire in cyl 3). Cleared the codes to start diagnosing.

First we swapped coil packs between cylinders 1 and 3. Still misfiring, and the p1399 reappeared quickly, but no specific cylinder code. I had a fresh set of NGK plugs on hand, so we swapped those and put the coil packs back on. Next crank, still missing, but this time we saw p1399 and p0301 (misfire cylinder 1). So, the misfire seems to be following the coil pack. FWIW, the 3 of the plugs were pretty clean (esp for 12 years and almost 80k miles), but the one in cylinder 3 was much darker. That sounds like a rich, possibly not-firing condition, right?

I ordered a new coil pack at the dealership this morning, should have it tomorrow. In the meantime, the s2k is sleeping at the parking lot at work.

Any other thoughts? Agree/disagree with the coil pack diagnosis?

 

Sounds logical if it followed the coil pack

 

When was the last time you did a valve adjustment?

 

It's been several years, and probably 30-40k miles since I last adjusted the valves. It's been on my to-do list, and I'll probably do it once I get the car home.

 

I just replaced the coil pack and she's running good as new. Codes have been cleared and nothing new thrown.

FWIW, I will mention that this is the first actual repair needed on the car after almost 13 years of ownership!

 

 

+1

Valve adjustment cleared my misfire.

darcy

 

Glad I came across this thread. Ever since I went boost I have been getting a CEL and it always comes as a misfire in all cyc. Changed plugs and came back right away. I am thinking my coils are done.