Idle Mainly Cold Idle

[ESTurbo4]

The car will only idle rich, especially when cold. I know when its cold you need some extra fuel but I think its a lot more than normal. The idle is on a Ford IAC controlled by a Haltech PS1000. Before I got the IAC to work I used the throttle stop screw and had to hold the gas pedal until it warmed up. Once warm it'd idle fine with the exception of being rich. It idles fine now on the IAC just the afr's are around the 12 mark hot. Before the IAC I blamed the lack of idle control and now I don't know.

 

I tried timing down the idle advance to 12° and up over 20° with no noticeable change (Haltech has zero throttle timing and fuel settings that're just for the idle). If I tune the afr's to like high 13's into the 14's it wants to stall. When cold it wants the afr's around 11.5 or richer and sometimes smokes from all the richness. However, you can start it up and drive it right away and it will drive fine.

 

Plugs are fairly new (less than 2000 miles) they are BPR8ES although after some searching the forum I ordered a set of BUR7EA11 (7031) as suggested to be the best option. Ignition is waste fire controlled directly by the Haltech. It doesn't miss or run bad unless I lean it out. Anyone have any insight?

 

Oh the wideband is an AEM UEGO the sensor itself is probably getting tired but the occasional smoking cold seems to confirm its rich readings.

[scott87star]

These cars like rich idle settings for best idle quality, nothing unique there. Are you reading the AFR's from the AEM or the Haltech, and do they match?

[Shelby]

sounds like you need to work on the start up enrichment tables sounds like they are set to high or too rich

the table gives several temp seting as the engine warms up and fuel enrichment canbe adjusted durring these times,, up untill the engine temp reaches such temp as it can run on the normal map , this isn't for a very long time normaly less then 1-2 min

[ESTurbo4]

The AFR's from Aem and Haltech match, but most of time I read them directly from the Aem gauge simply out of convenience. The cold enrichment table could use some tweaking for sure. However, once warm it still wants the idle mixture to be rich but Scott is saying its normal then I'll just play with the cold enrichment and let it run rich at warm idle.

 

I didn't wanna foul the plugs I know at idle they are not at self cleaning temp and are likely to foul in excessively rich conditions. Also accelerates the wear of the O2. What is an acceptable rich idle AFR in you're professional opinions? Thanks for taking the time guys I do appreciate it.

[Shelby]

any thing arround 12:1 at idle is fine , new car eminsions try to leanout idle fuel mixture to 14.7 due to eminsions , it has nothing to do with what the engine realy wants or needs ,, the rich mixture can lean out as the engine temp increases this is normal cause fuel more easily vaporizes when the intake and engine is hot,, this is why the fuel inrichment table is temp related

 

adjust your idle fuel untill you have the best idle but do NOT play with ign timeing to make idle better,, set ign timeing where it belongs , use the fuel mixture to get the best and smoothest idle you can , you can lean it out a little off idle as most do once the rpms hit 1800 of better , actualy turn off any fuel auto control such as 02 useage untill you have the fuel map looking good then turn it back on for fine tuneing self adjustments

 

do not set auto tuneing by 02 at more then 10% max ,,any more then 10% can cause a surge under cruise as the ecu trys to adjust fuel mix ,, under boost the 02 signal is not used to make fuel adjustments , you also want inj auto turn off under decell turned on , this will stop the plugs from being loaded up with unburnt fuel durring decell

[ESTurbo4]

Got it, thank you. I currently use fuel cut for deceleration, but don't have O2 control enabled at all. When the maps were a bit rougher then now O2 control would try and "fix" what it thought was wrong. I wont re-enable it until my maps are a little better still. In another few logs or so I should have it. Thanks again for the help on idle.