I have a 99 explorer 6cyl 4.0 sohcand this past summer no problems. This winter nothing butproblems. CEL was on andIput a new idle air control valve on and the next day it did not idle any different. Matter of fact it doesnt idle at all when it is cold. Turn the key, start it, and it idles high for about 2 seconds and shuts right off. Iwas told it could have been the temp coolant sensor. I put it in and still no different. The CEL was cleared before I put both new parts in. I started it the next morning and still no difference. Now the CELhas come back on and I went to autozone and the CEL code was reading idle air controlAGAIN. I told themI replaced it and they gave me a new one and I put it in and had the code cleared and still no difference.The CEL is now back on. What could it be? It has 88000 miles on it. I have replaced fuel filter, wires, plugs, oil and filter, thermostat, flushed radiator and block 3-4 times, new antifreeze, idle air control valve,and temp coolant sensor? What is wrong with this thing ? I am getting ready to shoot it and put it out of its misery.

 

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It sounds like the computer is telling you it needs more air. It must be shutting down the air flow. If the throttle isn't opening or the computer's closing it upquickly it will shut down. Could be a dirty air filter restricting air flow into the intake. Check to see if the filter's OK first.

 

Another thing - could be a damp/wet filter. This will shut it down until it warms up and dries it out.

 

I had the same problem. The cel will not come on if it's your AIR valve. I had 2 explorers and it happened to both. I have an 00 XLS with a 4.0 E engine. I had it scanned and both banks were lean. I replaced the upper intake manifold gaskets and the problem solved. It high idles when cold and settles down when warm. It's an easy repair and costs under $20 for the gaskets which really are O-rings.

 

There is even a way to check this - but it's me pissing people off if I do much but mention it - and since I'm not into getting my tail end beat off - I only mentioned it. I could definitely been oppositely wrong. Too much air - I just sometimes forget about gasket failures. Anyways to check spray some - *oops.

 

I tried spraying carb cleaner around the intake, didn't matter, just did the same thing. I put the scanner on it and I got a code that said banks 1&2 were lean. Must not have been that much of a leak because when it warmed up the gaskets swelled and the problem went away. I replaced the gaskets which are really O-rings and it runs like new. I've been a mechanic since 1966 I think I would know all the tricks, but I'm sure learning these new computerized cars. Thank God for the internet.

 

Carb cleaner is NOT very flammable. Starter fluid.

 

Too much ether will burn components - don't go nuts.

 

Starter fluid? I want to check for leaks not collect the insurance when it burns up!