Why the hell am i getting neg repd on all of my posts...

Anyway.

After I changed my plugs and moved to BP 93 octane it pretty much went away for a bit. Now it is back with a vengance. I am still pretty much clueless about this. It is very intermittant and there's no real rhythm to the dead miss i'm getting. It's either fuel delivery related, something is clogged, or some sensor is shot.

Does any of this sound like the injectors are clogged?

 

Have you replaced your cat? My car did the same thing almost 2 years ago. I did everything I could for cleaning everything in the air intake, TPS, MAP, anything you name it and still could not fix it. Replacing the cat with straight pipe solves the problems.

Borrow a test pipe or another car and run it if you haven't done it yet.

 

Great idea. Looked this up and it definitely fits. I would run a test pipe but I heard they make the air stink around the car and its toxic. Thoughts on that? If its not that bad ill definitely get a test pipe.

 

So finally met up with a fellow s2ki'er (wrecked)
1. we swapped MAP sensors...nothing
2. Compression test: 220-220-215-215...good.
3. He suggested swapping his coil packs with mine and when we were replacing them, I noticed the inside of my one coil had a white line going down it (which my dad later explained as the insulation breaking down over time and shorting). We swapped all the coils and it ran/idled great. Swapped back in that suspect coil and it came right back so it looks like i actually found the culprit this time. Got home, ordered a coil pack and cant wait to install it.

Thanks again wrecked!

 

No problem. Glad we figured it out!!

 

So is this a sign the coils are going bad?

 

The one coil at least yeah. Ill take a picture of the corrosion when the new one comes in and i swap it out.

 

Please keep us updated with this. I am having the same problem/symptoms and would like to see what the bad coil pack looks like so I can examine mine. The problem is driving me crazy.

 

Swapped out the coil pack and it runs great. I saved the coil pack so I'll try and get a picture for you to show you what I saw. Basically you want to look inside of the coil and look for discoloration of the rubber inside. Basically the inside of the coil is grey rubber and what I had was a white streak going down the inside of the coil that showed where the arcing was happening.

 

That's very interesting. Mine stalls every day on the way back from lunch in the same spot (clutch in to go over a speed bump at work). Nice and repeatable and aggravating. I've done the MAP cleaning and zip tie. Throttle body is new a couple months ago. Cleaned the IACV recently, no improvement.

Things on my list to try:
- Coolant bypass to IACV (another member said this fixed it for him)
- Idle adjustment
- New coil packs

Some people have suggested that the IACV freaks out if you have air bubbles in the coolant lines, and that causes the stumble / stall. When I cleaned my IACV, the coolant lines running to it were completely empty. Nothing leaked out. So I might have an air bubble to fix. That's why I'll try the bypass next.

But why do we need the IACV? If all it does is let in extra air to make the car idle high until it's warm, that's just dumb. I'd be happy with a car that just idles normally as soon as I turn it on. So, I've been thinking of fabricating a blocking plate to bolt between the manifold and the IACV, so the stupid valve can do whatever it wants and the engine won't notice. It'd be totally stealth that way too. The thing I don't know yet is whether the car can still idle with the IACV blocked off. If it can't, then instead of a thin plate I'll make a thicker one with a channel cut in it to allow some air to flow between the holes in the manifold.

Hopefully it won't come to this, but I'm super pissed that my car has stalled >30 times in the past few weeks. Worst case there are two great S2000 specialists in the Atlanta area, but they're not close to me so I'll mess around in the garage and try stuff first. If it's still not fixed by mid July, I'll ask my tuner to look at it during my next tune.