My Mustang starting stalling yesterday at stoplights. It only does it in drive and when it's warm. Thankfully it refires right back up and idles. If I shift into neutral before I stop it stays running. The car seems to run fine other than at idle. No problems with accelleration or cruise, just idle. Anyone have any suggestions where I should start looking?
Stalling on deceleration?
- Thread starter MYSTICSVT
- Start date
If you set the idle with the IAC connected and being used (having a duty cycle), the IAC might be dirty.
I choose to set the idle with the car in drive and the IAC disconnected (and no load on the engine).
Good luck.
I choose to set the idle with the car in drive and the IAC disconnected (and no load on the engine).
Good luck.
larrendeuce
Member
Mine did that when I didn't have in a speedo gear, only stalled when I used the air conditioning though.
gcwh02
New Member
gcwh02
New Member
By IAC disconnected do you mean just disconnecting the electronics to it? or the whole thing? I had my TPS adjusted while the IAC was connected, could that be a problem?HISSIN50 said:
You got it - disconnect the IAC electrical connector.gcwh02 said:
When you do this, you are assuming a baseline IAC duty cycle of 0%. You set your idle where you want it (on a hot motor with no electrical load like AC or lights, etc). Then clear the KAM (disconnect the battery, turn on headlights for 30 seconds, turn headlights off and reconnect battery). What you have done is set the idle at or above the factory setting without IAC input. This means the computer cant try to lower your setting, and it knows what the stock setting is and will try to get the idle lower. The only way it can feasibly do this is to shut the IAC, which you did when you set the idle. Cool!
Logic: When people set the idle with the IAC connected, it leaves room for the computer to remove IAC duty cycle (because there was some while setting the idle). This can lead to a hunting idle and surging.
Now on the TPS: it related to the computer the amount of throttle blade openness (word?). The IAC changes the idle without moving your throttle blade (as opposed to the idle stop screw, which DOES change the throttle blade position).
So cleaning the IAC should not affect the TPS setting. But when you change the idle setting with your idle stop screw, you can check the TPS reading to make sure it's still copacetic.
Good luck.
gcwh02
New Member
its getting worked on tomorrow so I'll let you guys know what I come up with... never ending problems
Thank's for all the help guys. I checked for codes and found a 29 and a 66. So I cleaned the MAF, replaced the VSS, and cleared the codes. All is perfect now. No more rough idle or stalling. And as an added bonus, my cruise had been working intermittantly, and now it's working constantly. :SNSign:
Well guys, it looks like I spoke too soon. My rough idle has returned. It starts idling fine and then just gradually gets worse until it stalls. Only does it in Drive. In Park it idles a little rough, but doesn't stall. I checked for codes again, but there are none on KOEO or KOER. Anyone have a suggestion? Since it disappeared for a little while after I cleaned the MAF is it probably the MAF going south?
See "Help me create the Surging Idle Checklist" at http://forums.stangnet.com/showthread.php?t=534062
for help with your idle problems. The first post contains all the updates to the fixes. I continue to update it as more people post fixes or ask questions.
for help with your idle problems. The first post contains all the updates to the fixes. I continue to update it as more people post fixes or ask questions.
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