HI guys let me start out by saying hello, my names Hunter im 21 and have owned my s2000 for about 7 months i have a goal to be able to show my car at HIN but its not ready as of right now, Eny way my car has this very annoying problem that after maybe 10 min of driving the car wants to cut off when its put in neutral i can prevent it from doing this by simply giving it a quick tap on the gas and it goes back to idling like it should also when its about 9-10 min into my drive it will dip to like 300 sit there for a while and out of no where jump up to normal idle or just cut of. Now it started happing very close to having my valves adjusted but could just be noting in common. its driving me nuts and i dont want to take it to honda because i know its gonna be 1000 bucks for a 100 doller or less fix

 

Mods?

 

Umm weapon-r short ram, E3 spark plugs, invida catback n1, fadanza lightweight flywheel, Act 6 puck clutch

 

im gonna go out on a limb and say spark plugs + short ram. Heat soak + a spark thast not powerful = crappy idle

 

well the crap idle started before i put on all of those parts well the spark plugs where put on today and made the power smoother but like i said it happend before i did the short ram. and oddly the car idles great but then its just like it forgot how to idle car runs great otherwise no cel. im thinking the valves are to tight

 

I guess a better way to put it is when the car's revs start to drop before 10es min the revs hold right at 1,000 perfectly after 10 mins it pass's 1,000 all the way to 0

 

So instead of fixing the car you just went ahead and modded it? I'd say get your priorities in order and start doing some research on this site. I'd wager good $ that your short-ram is losing power. I also don't agree with your choice in plugs...

Is the car actually stalling or is there just a dip in the rpms?

 

It stalls after its hot if i dont tap the gas and its only when its in neutral or ethere it sits at 300rpms for a while and then jumps back up to normal 1,000 rpms and i have invested money in trying to fix this im just not willing to take the plung and go to honda because im just throwing my money away.

 

Without more info there are many possible causes and we would just be guessing at a fix. My guess is a bad temp sensor.

You can replace that on a guess, do more research and get more info, take it to an independent mechanic, or ?

 

Check the idle air control valve. its most likely really dirty.