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  #1  
Old 08-22-2012, 04:34 PM
JDFeniello JDFeniello is offline
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Posts: 30
Default Sudden RPM Drop Confusion

Hey everyone,

This is one of my first posts, but i've been lurking for a while.

Just got a 94 4x4 4.0L V6 Manual with 225k.
my Old one is a 94 as well, but with an automatic (which I will be selling soon).

The engine runs strong, however, There is a moderate leak in the passenger side valve cover.

While coming out of a stop into 1st gear today, the engine suddenly lost significant power, and hitting the accelerator didn't raise the RMPs nearly as much as it should have(Maybe a miss fire?). i had to drive for a little while, and by the time i got to a suitable place to stop, the engine was smoking from the area around the leaking valve cover.

I pulled over and shut the engine down. A short while later, i started it up to move it further out of the way of the road, and the problem was gone. Hasn't returned all day.

There was a loose vacuum hose to the air filter which I put back on, other than that, nothing changed. I don't imagine one loose vacuum hose would be the culprit, but maybe it was?

Could it be a fouled Spark Plug from the oil leak? or loss of pressure due to the leak?

If anybody has any suggestions or info, i would appreciate it. This has me very puzzled because it was a one time thing, and i cant diagnose the problem if its not doing what it did.
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Owner of a 1994 V6 4.0 Liter Automatic Transmission Ranger with 4 Wheel Drive and the XLT extended cab package. 280,000+ Miles (Yeah i know its a lot. I signed up to Ford Ranger Forum so i could get information on how to fix it up)
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  #2  
Old 08-26-2012, 10:02 PM
scottgmacjr scottgmacjr is offline
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I second this I wknd having very similar problems.
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leak, misfire, oil, vacuum, valve



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