hodge9386

iTrader: (5)

2000 formula bolt on car, stock heads, stock cam, ls6 intake, lt headers, fipk, p&p tb and maf housing. i have the car running within a 2% error on the ve and maf tables but now i have a hanging idle issue when coasting. when coming to stop and i push the clutch in the car will hang around 1200 rpm untill i few sec after i come to a complete stop then it will drop to around 825. i raised the throttle cracker enable speed to 25mph and it did nothing, i zeroed out the throttle cracker table and it did nothing so i am lost with what else to try there. i also am having problems with the target idle speed. i changed it to 650 above 140* and did a entire write of the tune and it still idles at 825. i checked to see if the tb blade was closing all the way an it seems to be fine, i tried to adjust the idle screw on the tb and if i put it any lower the tb blade will just stick so i am assuming it is good. my tps reads 0% at idle. so i am at a loss at what to do next. i am new to tuning but the only things i can think of is my idle airfow is off since tuning the maf an ve or my idle spark is to high. i will post my tune and final log when i get home from work. any thoughts in the mean time?

thunderstruck507

iTrader: (18)

Just had a similar issue which turned out to be a partially malfunctioning IAC valve in the TB.

Owner had replaced it not too long ago but a new one still fixed it right up.

Ferocity02

iTrader: (60)

Try adjusting the idle airflow. I believe the trims can only handle so much.

hodge9386

iTrader: (5)

i ran the russ k cofig and fixed the hanging idle problem by zeroing out and setting the throttle cracker enable mph to 255. now i just have to figure out the reason i cant adjust the idle. i am going to clean out the tb and iac this weekend and see if that fixes it. today i checked for vaccume leaks and found none.

hodge9386

iTrader: (5)

i also noticed today when scaning i tried to force the idle down with the vcm controls but it still would not go below 825, i think when i comanded 500 it was idling at 800.

Ferocity02

iTrader: (60)

Sounds like an IAC problem or a leak. Or the hole in the TB is too big?

hodge9386

iTrader: (5)

not sure on the hole. im gonna plug the hole today an see what happens. friday im gonna take the tb off and clean all the crap out of it. is there any way to check the iac?

Ferocity02

iTrader: (60)

Try logging the IAC position (steps) and see if it's moving. Not sure, but maybe you can pull it off the TB but plug it in and turn the ignition on and off and see if it moves. Not sure if it is supposed to move or not...

Slowhawk

iTrader: (12)

Whats the iac count?

hodge9386

iTrader: (5)

not sure about count but the iac position was at 180 at start up cold on slowly worked its way down to 0 at 120* and stayed there in the idle config i posted above.

Ferocity02

iTrader: (60)

If its 0 when warm I think that means that its trying to reduce the idle speed but cant anymore since it bottomed out at 0. So sounds like there is an issue here.

Slowhawk

iTrader: (12)

0 is the problem. Try closing the throttle body blade when it's warm to get a 40-80 count on iac.

hodge9386

iTrader: (5)

the throttle blade is as close as its gonna get. i took the tb off yesterday and cleaned it out and cleaned the iac sensor out (they wasnt that dirty) and put them back on and it didn't really help anything but i noticed the hole in the tb looked a lil big so i put some gorilla tape on it an it went right down to 650ish where i have it set. i took the tape off an put a screw in the whole with a lock washer and nut with some red loc tight and ground it down and it seems to be good for now. prolly just look for a shaner ported tb that hasnt been drilled to replace it. i will have to wait till i get hpt back from my buddy to make sure its working right.


thanks for all the help guys

MUSTANGBRKR02

iTrader: (91)

If the problem started after you tuned it then the tune isn't correct.

hodge9386

iTrader: (5)

the tune is fine. i put the stock tune back in it and tried to lower the rpms and it still wouldn't go down past 825. i just never noticed there was a problem till i got hp tuners and tried to lower the rpms.

MUSTANGBRKR02

iTrader: (91)

After you get it fixed then you will need to do some retuning.

hodge9386

iTrader: (5)

yea, the idle airflow will prolly be all off. ill look it all over again in a couple weeks.

Slowhawk

iTrader: (12)

Yup, over ported throttle body or a hole drilled too big.

Shaner are the one's we have the most problems with.

hodge9386

iTrader: (5)

i ported the tb myself and all i really did is smooth it out i didnt really "port" it. i stayed at least a half inch away from the blade so i dint screw it up. idont know who drilled the hole but it wasnt me. i need to enable throttle cracker and redo the idle airflow again because when i push in on the clutch it will drop down to around 300 rpm and then come back up, it kinda stumbles looking for the right idle a lil bit to.

which ported throttle body do you recommend?

MUSTANGBRKR02

iTrader: (91)

I would try a stock one, got to be someone around there with one.