99 Mountaineer wont idle when damp out

[Hunter66]

After a rain or damp spell, when I start it, it wont idle I have to step on the gas a little until it warms then it can idle itself.Its getting worse over time.Its fine when driving after it warms up it seems,

while it was running rough I removed the air intake placed my hand inside blocking the air just slightly and it would stall. Could it be the MAF sensor???
ALSO when first starting the idle is real low.Normally when you start it, it would idle high then go low. 10 months ago I did the fuel filter
When I rev it up in and driving it acts normal plenty of power.

99 Mountaineer V8 AWD 177,000

 

[CDW6212R]

Check the tune up items, change what is old. Do you have any PCM codes? Try cleaning the usual things, MAF, TB, and IAC solenoid. Pull the MAF connector at idle, it should not make a noticeable difference.

 

[Hunter66]

I did new plugs wires 6- 7 months ago How do you clean the MAF sensor?? I get no codes.

Does that rule out MAF if no change happens at idle when I disconnect

 

[CDW6212R]

Use a throttle body kind of cleaner for the MAF and TB, it's not as harsh as carburetor cleaner etc. The MAF isn't easy to diagnose, sometimes it makes a big difference and suggests a harder look at it. it's not a definitive test but better than nothing, testing the voltage is best for it(1-5 volts).

 

[Hunter66]

I just went out and started it again this time it was like nothng was wrong idle was perfect and strong. Im starting to think from reading here it may be the camshaft position sensor.
I will give it a good cleaning anyway the MAF

 

[CDW6212R]

Yes, the CMP is another place to go if the tune up stuff doesn't point to something.

 

[Hunter66]

It looks like the sensor is seprate from the drive, should I just replace the sensor first
In Hanes it looks like the sensor is the EZ part. How would I know if the drive is bad, I did hear some chirppin near the PS pump when it was running rough.

 

[CDW6212R]

The housing is like any distributor, high mileage will wear out the bearings(squeal). I'll be going to NAPA for mine, I recall about $85 from them.

Avoid the cheap CMP sensors, they tend to not last long.

 

[Hunter66]

How do Figure out if I need a step on plug? I looked on the Autozone site and it has two kinds

 

[Hunter66]

Ok think I got it, unhook batt, take belt off, remove plugs, use socket to rotate crank clockwise while my finger is on the number 1, feel air push out until it stops look at crank location rotate back 6 teeth CCwise. unbolt censor unplug it, pull it out, use new tool to align new shaft place it back in the hole secure, plug in install plugs belt and batt then start. BOOM hope thats it or close plan to do it this week.

 

[CDW6212R]

That sounds very close, hopefully that's all it is. Regards,