street_ruler

yah but it wouldnt cause a miss fire at low RPM (like driving around town under 3k) it would only be more apperant at higher RPM. and plugs dont tend to foul as tehy get older thats a problem with oil, the mixture, water ect. if they are old they just dont conduct as well.

a miss fire is a detonation where the mixture ignites prematurely before the piston reaches its desired mark before TDC. the only thing that would cause this in our cars is a coil malfunction or a bad crank angle/cam sensor. not an old plug.

when plugs get old they just dont ignite as well and are not as efficent...mileage goes down...stuff like that. almost unnoticeable unless you swap in a new set of plugs.



if you want to test the plugs, go to your friends house thats a geek, and borrow a multimeter and see what teh resistance is. then (and be brave)disconnect the fuel pump, start the car and let it die (so you know it wont run but will turn over) remove a plug, attach teh butt end to the coil pack and hold the electrode end about an inch from the shock tower strut bolt...NOT A PAINTED SURFACE. no ahve you friend crank the motor over. it should arc.

CAUTION: DO NOT TOUCH THE CAR WITH YOUR BODY WHILE DOING THIS!!!!!!! the guy cranking the car is fine but if you are holding the plug DO NOT TOUCH TEH CAR!!!! YOU WILL GET SHOCKED and believe me...it hurts, mostly your arm but your pride hurts just barely less.

as for above...i would defenitely ahve a compression and leak down test done. then check your retainers to see if a valve looks like its dropped (cracked retainer)

if thats the case, and a valve dropped its because someone missed a gear and over revved it.

good luck man. take no prisioners.

RedY2KS2k

??????????????????

Sideways

Prematurely indicates pre-ignition or knock.

ShocK

lol

street_ruler

yah sorry detonation is the "technical" word for a misfire. people say it sounds like marbles in a coffee can rattling around but i think its more of a "denser" sound. like the marbles in a 4 inch thick walled coffee can. its actually the piston slamming into the walls of the cylinder and bouncing off

SenderGreen

Really? I thought misfire meant lack of detonation.

detonation=pre-ignition=knock (same thing)

misfire=unburnt fuel (no combustion or detonation whatsoever)

BTW. I'm pretty sure stock S2000 plugs are Platinum, not Iridium unless Honda has changed something.

To the OP. I suppose it is possible that someone mechanically over-reved your car by "money shifting" to a lower gear while attempting to upshift to a higher gear. This can cause extensive damage to the valve's. If the valve's or valvetrain are damaged the cylinders will fail to seal correctly. If the cylinders do not seal correctly they cannot pressurize the air/fuel mixture enough to facilitate any detonation/combustion, and cause severe misfiring. If your CEL is flashing you should not be running the engine at all. This is not only because a misifre can dump unburned fuel into the exhaust and catalytic converter possibly causing damage to the Cat. Converter or O2 sensor. Unburned fuel can also "wash out" a cylinder and cause scoring which can also lead to loss of compression.

Also I'm not sure I would just clear the ECM. The freeze frame/snapshot can tell some stuff about the conditions when the DTC occured.
I hate reading stories like this...
Good Luck.

EDIT: Disclaimer, Many things can cause a misfire; Fuel, Plugs, Coils, Injectors, valves, etc. I was trying to describe what I considered to be a possible, or dare I even say probable scenario.

Maybe get some stock Platinum NGK's

SenderGreen

I would think no CEL at dropoff, then CEL flashing at time of pickup would pretty much indicate fault/liability on the part of the tire shop.

Did you bring the Check Engine Light to anyones attention before driving off?

Did they bring the Check Engine Light to your attention when you dropped the car off?

I added the second question as an afterthought because they are both relevant. I understand that they could not have pointed it out because it was not on.

Seattle2k

i believe there's someone in the "for sale" forum, parting out a car, including coil packs.

SoCalIsMyLife

This is why I never let any shop, whether it's a dealer, chain, or local shop work on my car. Sorry to hear about that bro.

street_ruler

that cant be the case becaust why would that cause a problem? the engien would just spit out the unburnt fuel and on the next combustion cycle it would fire again correctly (if nothing were broken)

and if it did "misfire" with your definition then it would be constantly running on 3 cyl. if you want to knwo what that feels like go for a ride in your friends diessel truck. its insanely rough and if you cant tell something is wrong...you got bigger problems


but no, a miss fire is a pre-ignition, knock, detonation ect.

and as for iridium vs platnum....never run a platnum plug in a honda...period.

and unless they are balls to the wall nice platnums they shouldnt be 80 bucks for a set. thats iridium territory. the essiest way to tell is if the electrode looks like a needle or something else. needle=iridium (i still stand by the price being more of an indicator though) anything else = platnum, copper...ect.