cold high idle, then dies.....

[kuch73]

Hello all, I have a 99 Explorer 4.0 SOHC, when first start on a cold day, the engine would idle real high, like 2300rpm for about 5 minutes, then die. I have installed a new ECT sensor, when I did the 00M12 gaskets. This problem is intermittent as well, so I do not suspect a vacuum leak. Any other ideas, FPR, fuel filter, etc... Thanks

 

[llamaking122]

have you tried cleaning the Idle air control?

 

[RoCkrMAN]

Temp sensor fixed my 5.0 it would idle high then low till it died. And its not the sensor for the gauge its the other temp sensor.

 

[kuch73]

Yes to both....

I installed a new ECT sensor, direct from Ford, and have cleaned the IAC valve. It still has the old IAC valve, just cleaned, hoever, I have tried 2 other used IAC valves and same random high idle. Any other ideas? Thanks