Ok i just bought a 99 honda civic with jdm b18c swap and skunk2 intake. The car idles rough when cold till it warms up which i think is the fitv. I drove it home 300 miles and runs great on the highway. The only problem im not sure about is, when i get into vtec and then come to a light. The idle will surge from 1500-3k rpms. It will do that till i turn the car off and restart it, then it idles around 1k. Everytime i hit vtec, afterwards it would idle up and down till i turned the car off and back on again. If i drove normal and never hit vtec, it seemed to idle fine. I think the guy said it is running a p04 chipped computer. Could it be that i just need to put a p73 computer in or maybe sticking vtec solenoid? Any one ever have this problem. Im new to modded hondas so any help would be appreciated. Thanks

 

try clean the iacv first then let us know if this surging still continues

 

ok this may be a dumb question, but how do i know vtec is kicking in? I mean i hear the engine get louder around 5500 rpm and pulls harder. Is that basically it. It pulls hard all the way to 8k rpm maybe higher, havent hit fuel cut off. 1st gear isnt really strong, 2nd gear is stronger up top, and then 3rd gear pulls hard. Im wondering how he could have gotten vtec to work with a p04 computer which is non vtec

 

open it up and look if its been chipped, this link shows were vtec can be hooked up.
http://www.xenocron.com/install/11f0.htm

this link at the bottom shows a pic of a chipped ecu
https://www.hondacivicforum.com/foru...ad.php?t=73241

you can hook up a 12v vtec light it will come on when vtec kicks in,

 

Don't go over 8000 rpm, if it's chipped the rev limiter may have been disabled and you'll blow the engine.

You could also unplug the VTEC solenoid and test drive again, if it was working you will notice a difference. On a stock ECU this will light the CEL and trigger "limp home" mode where it won't rev over 5000-- do not panic-- simply reconnect the VTEC and restart the engine.

 

yeah i didnt want to go passed 8k. 8k is enough anyways. usually dont they just move the fuel cutoff up instead or removing the rev limiter? My last car i had chipped but it just moved the rev limiter higher and remapped the fuel curve throughout the rpm range.