Transmission Killing Engine

[KCK71]

I've got a 1999 Explorer that has started to have an issue of the engine killing when I slow down to stop at a stop sign, when parking, etc. It feels like what would happen if I was driving a stick shift and didn't push the clutch in when stopping. I can avoid it some by shifting into neutral just before trying to come to a stop. Even if the engine doesn't kill at a stop, it will often run rough and idle speed will surge from 500-800, something like that.

Of course when I took it to my repair shop it didn't replicate the issue...I find it happens more after driving at highway speeds for 15-20 minutes and then coming to stops after that. Any ideas on what might be causing these symptoms? Thanks for the help.

 

[FijiBill]

idle air controller

 

[Redmanss]

What kind of general maintenance have you done to it lately, and what's the mileage? Sluggish operation like that sounds like something going on in the fuel delivery and/or ignition, so simple replacement of fuel filter and spark plugs if they're overdue might solve it for you.

I had similar issues with my girlfriend's '04 4.0L with over 200k miles of a lot of commuting on it, bogging down in traffic and stalling out at lights. I thought it was the fuel pump going bad but the above solved it once I found out it had basically had nothing but oil changes done to it over its life.

If you've done all that recently, then sounds like FijiBill is on the money.

 

[Jason94sport]

Or MAS, or TPS, all easy to test or replace.

 

[KCK71]

Thanks for the help. Would any of these problems cause the Check Engine light to come on? Currently it's not on when the problem occurs.

 

[TKZ]

I had a similar problem with my green 98 5.0 turned out to be in the valve body .
this is the post 1998 Mountaineer stalling

 

[fast_dave]

idle air controller

^ Ditto ^

 

[koda2000]

Possibly the IAC valve, which the PCM uses to control the idle. I don't think the MAF is your issue, as it doesn't even need to be connected at idle and I don't see how the TPS can case a low idle or stalling. My other thoughts are problems with the torque converter or possibly the transmission.

When's the last time you did a tune up (plugs, wires, PCV valve, clean the IAC, MAF and throttle body)? There are quite a few things that can cause stalling at idle, most will turn on the CEL, but not all.