Stalls when cold....

[inkjunkie]

Afternoon folks...have not visited here in a very long time....I do apologize.

Our 99 Explorer is acting up. 4.0 SOHC. Just plugged in my laptop with Auto Engunity scanner software in it...typed in all the necessary info to start a scan of everything.....nada....

Problem is failure to idle when cold. Started acting up a month or so ago...and true to my ways of late I have just been ignoring it. Well it will not idle at all anymore. Start it up and out it goes. Hold the go pedal so the tach reads 1200 rpm or so for a minute...and out it goes.

Thinking it may be a vac leak...but fuel mileage is still the same as well as the performance. Of course not ruling it out.

Have not cleaned the throttle body in ages, could it be related?

 

[2000StreetRod]

DTCs?

Do you have any DTCs? If not, try to get your scanning program to read the engine coolant temperature (ECT) pid.

 

[intelisevil]

Stuck/dirty IAC valve?

My '00 SOHC had a similar problem, when I came to a stop light I had to shift to neutral and keep the idle up.

About 10 minutes to remove, clean with electrical contact cleaner, blow dry and reassemble. $50-80 for a new part.

Good Luck,

 

[inkjunkie]

Do you have any DTCs? If not, try to get your scanning program to read the engine coolant temperature (ECT) pid.

No Sir, no codes. Will plug the laptop in next chance I get. Won't be tomorrow, wheel bearing crapper out in my diesel pickemup...

Stuck/dirty IAC valve?

My '00 SOHC had a similar problem, when I came to a stop light I had to shift to neutral and keep the idle up.

About 10 minutes to remove, clean with electrical contact cleaner, blow dry and reassemble. $50-80 for a new part.

Good Luck,

Will be investigating this as well...Thanks for the advice...

 

[gatzdon]

Is your tool able to scan for the extended Ford codes, or just the OBDII codes?

 

[gatzdon]

Also, don't hit the DTC reset. It resets all counters that could trigger a code that helps you find the problem.

 

[wcjeep]

My 1999 had various problems that were mostly neglected maintenance from previous owner. It had a similar problem to what you are describing. The final item to achieve idle during cold engine and cold weather was gaskets. The Ford plastic intake needed new gaskets. Also needed a new gasket for the iac. I used Fel Pro. The intake gaskets were about $23. Iac gasket was about $2.50. The factory gasket appears to shrink over time. When the engine warms up the old gasket expands. Partially sealing the intake. Verify the torque settings for the bolts. Do not rely solely on a Chilton/Haynes. My book was wrong. Snapped one of the bolts. The lower plastic intake bolt is a little different. It's a torx head, wood screw thread, and odd length.

The gasket swap is not difficult. Be sure to take your time. There are various YouTube videos that mostly apply. Ford engines had different configurations depending on vehicle and model year.