notaloafer

I've not been able to pin down why my s2000 keeps throwing a CEL every few thousand miles. It seems that if I constantly add Techron to the fuel, it keeps the problem under control. As soon as I go a couple of tanks without adding Techron, I get a CEL random misfire. Eventually I'll have misfire codes for all four cylinders and the random misfire one. However, the engine itself sounds just fine? I know what misfiring sounds like and it's not doing it (unless it's just one here and there under load that I'm missing).

All of this seemed to start right before I switched out the OEM AP1 retainers with AP2 retainers. I got my first CEL misfire about a week before I did that job, so I don't think it's related. I did the valve adjustments myself after the retainer swap (I've done valves in the past on my truck and know how to do it also). It seems though, unless I keep adding Techron, I keep getting a random misfire on different cylinders. There's no rhyme or reason to it and I can't seem to find a pattern. I always use 92+ octane Chevron fuel or 76.

Yesterday (after changing the battery out, may have just been because the engine computer had to re-learn?) I got a flashing CEL as soon as I started it up after changing the battery. My heart immediately skipped a beat and I turned it off in a split second. When I turned the key to the ON position, the CEL was not illuminated, so I started it up. Drove about 200 miles since then, and no CEL again. It was strange that the flashing CEL went completely off without me having to do a ECU reset.

Any ideas, anyone? The spark plugs are OEM and only have 20,000 miles on them. Again, the only thing that seems to alleviate the issue is adding Techron. Could my fuel injectors really be gummed up to the point where the Techron is just a band-aid to keep the misfiring at bay? What's with the sudden flashing CEL in that case? Could that have just been the engine re-adjusting the mixture after swapping out the battery? The flashing CEL was the only time I could audibly hear the engine struggling with idling.

Thanks!

PS - My car revs to the redline without any hesitation, compression is all in the 240s across all cylinders, and everything seems to check out. It's not stalling at all or acting like it's hesitating whatsoever. The CEL usually only comes on at idle, or below 4k RPM.

notaloafer

My theories are either my valve adjustment may have been off, or the fuel injectors are either shot or really dirty. Anyone else's ideas would be well appreciated!

bgoetz

Send those injectors off to be cleaned!!

notaloafer

So you don't think just adding enormous amounts of Techron over time will do the job..? =P Who is someone reputable who can do the injector cleanings / how much $ will I be shelling out?

Gotpepsi

I don't think Techron will do the job, nor will in engine cleaners like seafoam. When I had a misfire I could hear the exhaust popping. My misfire was due to sticky injectors. I purchased 4 new injectors for 400$.
Google injector ultrasonic. You will get some hits on shops who provide this service. Also YouTube a homemade injector cleaner, its pretty interesting.

sillyboybmxer

user here cleans injectors
https://www.s2ki.com/s2000/topic/976...ector-cleaner/

Slowcrash_101

PM Wadzii on these forums, he can do a proper injector cleaning. It's cheaper than buying new ones.

Billman250

This is your best bet right here. Wadzii cleaning involves flow testing to be sure they are equal. Fast turn around.

MR.T

X2. Great service and very timely

notaloafer

As usual, thanks guys!