so i have a 99 integra gsr, b18c1 head and b20z block, when i first did the swap it ran fine on the stock ecu, when it acted up i got a p28 and dyno tuned it professionally, but ever since it started acting up before i got it tuned it does the same thing and my tuner told me he didnt think it anything to do with the tune. when i start it after it hasnt ran for a little while, maybe overnight, no matter if its cold or hot outside, it will start and get up to about 1000 then just drop down and die, but if i push the gas in a little bit it will stay on and after maybe 45 seconds to a minute i see the rpms start raising and i can let off and they go to what they normally would be if i just started it. when ive already been driving it and its warm it will start up fine, whenever the engine has cooled down it does this even if its not cooled overnight even if its just a few hours. also, when driving and i pop it into neutral the rpms go way down to about 200 and then fluctuate for a few seconds before getting up to 800 or so, if its really hot and im in neutral they will just sit at 200 sometimes.I have no clue what this is and i was wondering if anyone had any kind of suggestion at all, thanks guys

 

do you think it could be my iac valve?

 

could be..try flushing out air bubbles in your coolant sytem and try unplugging the IACV when the car is on. see if it"ll react different

 

do you have any cel's on?

 

no cel's on, just to describe it more, when i start it and it acts all weird, it sounds like its cammed or something, its all loud and after the 45 seconds or a minute of tapping the gas in to keep it a 1000 rpms i can hear it kind of snap back into normal and it stops sounding so loud, i already tried flushing out my bubbles in the coolant but i havent messed with the IACV at all, thanks for the help so far guys

 

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what is a cel?

 

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any vac. leaks? when you drive it is it ok

 

no vac leaks, i checked, when i drive its fine except for when i slow down and throw it in neutral it will go down to 200 or so. if i stop driving for a minute and just idle, it will go back up to maybe 500. also when im stopped and start, ill have the rpms at about 1000-1200 when letting off my clutch in first and i can feel a kind of popping feeling like a studder. and if i dont give it a little more gas then i have to stop and start again

 

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CEL stands for Check engine light

 

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