schecterplayer

the original problem has been idle issues but they were resolved with a idle reset. The car was working fine until the iac died but I didn't catch that until after I messed with the idle again thinking that was the problem. I set the idle to higher than whay4 I thought it was set originally and it idles great now. I must be going crazy lol. I'm going to get that iac plate to aid the iac in holding a lower idle

yurizx6r

Ok. Just making sure it wasn't an ignition issue. It's not popping under WOT right? It's tuned correctly and all that? Either way good job getting a Motorcraft IAC. Can't beat OEM on some things.

schecterplayer

no. The car is tuned perfectly on the stock ecu. It runs strong and when it's set properly. Idles perfect. Question though. I have the idle set q little higher than I would want it. It's the only way the car will correctly. If I set it to stock idle speed it will hold it and idle correctly until the car is turned off and restarted. Then it surges and dies. If I were to get the iac adjuster plate, should I be able to set the idle lower than it is now(900-1000)? All the plate does is allow more air in than the iac can do correct?

Boss_Hotrod

You might have the it idling too rich. Only way to know for sure is with a wideband o2 or looking at the pcm. Also sounds like the idle is way too low causing the iac to do too much work. Try bumping the idle speed up to about 800-900 rpms. Usually a rich condition causes these cars to surge and with the top end kit it might be doing just that.

Just for information purposes, Im running a Holley Dominator EFI on my car and mine idles at 975 with the throttle open just enough where my iac shows 0-2% duty cycle with the car up to temp. Basically its running without an IAC unless the car starts to get to rich at idle and the PCM tells it to open a little. Also my idle AFR's are right around 17:1 changes to 13.0-13.5:1 at tip in.

schecterplayer

thanks for the info. I have the idle manually set at the throttle body to about 900. The iac does not assist idle at thie point. Only oon startups and when ac is on. Also I don't know if I mentioned this but my biggest issue was that when my iac died I messed with the idle and set it lower than what it needs. So my problem seems to have been resolved

Boss_Hotrod

The car most likely wont idle that low with the cam in the motor. Not sure what stock 5.0s idle at but when you start adding bigger cams youll have to bump idle speed up to compensate for it.

Just throwing this out there, some drag cars idle at 2500 becuase of how the motor is built, plus they dont give a crap about fuel economy either, just have to perform.