[align=left]i am mechanically inclined, but new to imports.
I have a 94 civic ex, mods include; jackson racing supercharger (running 6 lbs of boost), JR boost timing controller, cold air intake, magnaflow header back exhaust, msd ignition, and no mods to ecu. used as daily driver.
Problem:
the car, when cold, will fluctuate in rpm rythmically until the car warms up. the rpms will go from <1000 up to about 2300 and back again. over and over until i seriously consider offing myself because of how annoying it is.
What i think it is:
i think, since there are no mods to the ecu to let it know there is boost, when the rpms get to around 2300, a little boost is making the engine want more fuel. the ecu says no and cuts fuel, once rpms get below normal idle, the ecu starts to add fuel, then the whole cycle starts over.
Question:
is there any after market anything to solve this annoyance? or am i wrong in my theory? has anyone with similar mods experienced this same issue? any help would be a big help.
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hello. Welcome to HCF. JRCS's are made so they can run without having to tune the ecu. But I bet sov would be able to help you more because he has had one before and i have never had one. But Lots of hondas do this. Its trying to get to normal operating temperature as fast as possible. My honda does it and all i have is a SRI. But what your saying is that once it warms up it goes back down?

 

yes, once engine is warmed up and idle drops, it stays at a normal idle. thats why i thought it had something to do with boost, because at normal idle there should be no boost at all, but like all cars they idle high when they are cold, idling high means a little boost.
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my car idles up to 2300 then to 1000 sometimes and im running no boost.

 

does it fluctuate rythmically until the car warms up? im talkin pretty quick rythm too, it will be up to 2300 and back below 1000 within one second, then back to 2300, over and over.
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Yea my car has done that. I still can't figure out why it does that sometimes.

 

one suggestion is you might want to spray some carb cleaner through ur manifold near the iacv port, had the same problem because gas got into the iacv which makes it a lil jumpy, just remove the throttle body and give it a spray.

 

Two basic things worth trying:

1) Clean the IACV (as mentioned by rcalimquim):

http://www.superhonda.com/forum/f94/...r-iacv-144463/

2) Bleed the cooling system of possible air bubbles:

 

thanks guys, ill give it a shot and post results.
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ok, i cleaned iac valve (even though it was not dirty at all), and i bled the coolant thoroughly. still nothing! im wondering if my first thought is true after all? could the ecu be battling with the supercharger? the iac valve reads vacuum if im not mistaken, if there is too much vacuum it will cut back fuel. am i retarded by thinking this way???? someone teach me the error of my ways please!
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