Hondata

I have a 99' civic si with a B18c1 block bored 40 over with forged pistons. A B16 head with integra type R cams and 11.5:1 comp. S300 with a P28 ecu. Ever since I put the S300 in the idle has been moving up and down during cold start untill it warms up. After it has warmed up it idles fine. Could something in the calibration be causing this? Its a stock integra type R calibration with slight modification to the fuel curve and V-Tec.

You may have a slight vac leak that only occures when it is cold, or you may jsut need to adjust your idle manually as the Helms manual states with the idle adjust screw. It could also just be an adjustment that needs to be made in the idle section of parameters.

FITV?

my car has no idle on cold start unless i keep the throttle pressed for a while till it catches the idle (though its a pretty low idle)

Car wont respond at all if i mess on the iacv duty cycle, i´m considering it might be busted.

Once i start driving the car around it will idle normaly but as soon as i hit boost it will have a hunting idle from 1000-2500.

I tried disconnecting the iacv but car just dies once i do it, cant really say for sure its a vaccum leak but i cant spot it either.


P.S - Stock map sensor and the car drives just fine besides this issue, since its an itr it has no fitv

Try following the factory service manual's method of properly setting the idle. If you think it may be a bad idle control valve, try swapping it.

my cars idle is terrebly high too...... i replaced all gaskets... on the intake i installed the spoon ventuli gasket and on the trottle i got the hondata one.....and still same problem...... i got my s300 on a p28 lots of mods but just wondering why is this..???

REDR.

I got the same problem but my motor is N/A.

Will not idle at cold start. Im throwing CEL 14 and it idles good after warmed up.

I replaced IACV,TPS and MAP....No difference.

Im thinking my situation is a wiring problem then proper idle adjustment.

i too have problems with cold idle i have to give it throttle for 30 secs or so then slowly release for it to idle. if i dont do this my car just dies from no idle.. this has only been happening since winter (freezing temps im from toronto, canada) no problems in warmer temps tho.

is it possible that were getting bad / no idle at cold start because of not having FITV?? FITV is what adjust the idle at cold start with stock OBD1

my car is originally a 96 gsr obd2 which uses no FITV rather the ecu uses the IACV to do the job of the FITV.

now that i have converted to OBD1 ecu (p72) chipped with s300, shouldnt i also need to swap to a obd1 throttle body that has the FITV???

ive read of people bypassing the FITV without problems so im stumped any one have any ideas?

thanks

my car has a low/rough idle until the car warms up a little then all is fine. Only happens during winter months here in ohio.

Do you guys have a wideband? if so what are you A/F at cold starts?

i have a wideband its reading pretty rich about 12:1 i tried to lean it out a bit which seemed to help at like 12.5

laziebun wrote:Do you guys have a wideband? if so what are you A/F at cold starts?

On a warmer day (70 deg F+ coolant temp), I know I can run post cold start at around 14.0:1 AFR without misfiring. I can probably go leaner, especially as the coolant temps get above 100 deg F.

In the winter (no lower than 10 deg F), I have the fuel enrichment vs. coolant temp to do about 12:1 AFR after it can idle on its own (usually about 10 to 15 sec). I've never tried to start the car at anything below 10 deg F.

If I'm at home, I use the block heater to get the coolant temp to 60 deg F in the winter and it'll start without my throttle input.

Cams are Skunk2 Pro2's and the injectors were Rochester MSD SCI 395cc/min. Oh, and it's a P72 ECU, no FITV, OBD-2 IACV with coolant circumvention.

I love the S300. Simple with lots of functionality.

irsdb7 fixed your problem yet?

no i havnt its much too cold to be outside and try troubleshooting im thinking that its much too rich at cold post start. when i start the car the A/F is ~12.0
everywhere seems to tell me that this issue isnt related to not having a FITV so i dont know.

would a 12.0 a/f cause my engine to bog and die?
i have a gsr with a compression ratio 12.5:1 im running a stock itr fuel table with a 15% overall fuel trim. im running a skunk2 IM

list your email here ill send u the solution