Hello,

I have a 2004 Ranger 2WD with the 2.3L and a 5 speed. I recenly purchased this truck and it is now having a issue.

The truck starts to stall as it warms up. It starts up perfectly when cold and idles fine. But once it gets warm the idle drops to around 400-500 and then sometimes stalls completely but restarts right away and idle fine around 800.

The check engine light is not on.

I cleaned the IAC and MAF and replaced the fuel filter.

Any insights or things I can test?

Unplug the egr.

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1997 B2300 reg cab 2.3 Lima, 15x8.5 Mickey Thompson classic 2, 31x10.50 cooper discover at3, 7.5 open 4.10 rear, dynomax super turbo catback, alpine iva-w200 w/ nav, kicker 6x8s, alpine type R 8, alpine 250W mono amp, power bass 400.4, tool box & camper shell, compustar alarm/remote start.
1956 Ford F100 rust bucket with big plans!

If not the egr, unplug the ECT (temp) sensor.

Ok I'll try that. Now unplugging the EGR or ECT with result in a higher idle?

And on this engine the EGR is on the back of the head?

EGR and ECT are both on the back of the head. Good luck wiggling around to either one without at least removing the valve cover. You might be able to get the electrical connectors off, but you'll be running through a list of every swear word you can think of trying to plug anything back in.

It very well could be an IAC valve that's going out. If the idle drops again, pull the hood open and yank the plug on it. If the idle doesn't change at all, then the IAC valve is closed. Normally, that would trigger a CEL, but if it's intermittent like that, it'll probably stick as a pending code. Can you confirm that there are no pending codes either?

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2003 Ford Ranger XLT
2.3L I4 Duratec DOHC, 5R44E 5-speed auto, RWD, 7.5" Open w/ 4.10 Ratio, Gibson split-rear catback
Sonic Blue Pearl with dark gray trim

Had an issue similar to this with my truck. I took it to my dealer and they reset the ECU and it's been running fine ever since.

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2008 Ranger XLT | 2.3L | 2WD | 5-Speed Manual | Flowmaster Exhaust | Aftermarket Fogs | AFE Cold Air Intake

I'll see if there are pending codes tomorrow, the idle sometime "hunts" so maybe I should just replace the IACV. I'm glad ford picked such a convenient place for those sensors.

Ok I don't even know how to get to these sensors, but there are no pending codes. Could the CHT (if it has one) be something to look at as well? My temp gauge seems to function correctly.

Just posting what I found in-case someone else is having a similar issue.

Pulled the plug from the CHT and the truck would idle down to 600 rpms when warm. Thinking this could have been giving the computer a faulty reading.