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Old 05-05-2013, 08:13 PM
Rangerman49 Rangerman49 is offline
If it works,don't fix it!
Join Date: Dec 2011
Posts: 966
Default Re: Engine miss.............

Originally Posted by JMJ View Post
Have 2008 XLT 3.0 Ranger. Having a problem with a engine miss. Truck has 72,251 mile on it. Took to local Auto Zone store and had a test done.
The test showed that # 6 plug wire was misfireing or ignition wires or coil could also be the problem. Also a possible vacuum leak, injector fault or high or low fuel pressure.

I cleaned the Mass air filter flow senor (MAF) and also cleaned the Idle Air by pass valve. Used the correct cleaner. Checked all of the vacuum hoses that I could fine with leak teck and no leaks noted.

Changed all spark plugs and ignition wires using Motorcraft parts. Still had miss but not that bad. Decided to change coil and that did not help either.
I am going to change the fuel filter and see what happens. All of these parts that I change out were orginial item install on truck when new.

The rough idle seem only when I start up in the morings. The truck shakes but after it warms up it seem to run fine. I do notice at idle the needle fluxes between 650 and 700 RPM. It seems to be running fine but when I stop at a light and the longer I sit there the more is seem to idle rough. It has never stopped on me at any light but just idle very rough.

Question is......What do I do next??? Have the fuel injectors check out? Do a compression check? It seems to be running just fine on the highway. After I changed all of the above items I got 18 MPG which before I only got 14 to15 MPG

This is the second Ford product that I owned. I did have a RV camper with a V-10 engine which ran like a champ. Have always been a Chevy man for many years and just hope I did not make a mistake by going over to Ford. I really liike the truck but the miss is getting to me. Please help or suggest what to do next. Thanks in advance...................... Thank You..............JMJ

Do you remember what the code was, like Pxxxx ?

The ruff idle could be the EGR valve not fully seating because it's gummed up with carbon, remove and clean with carb cleaner. Would be a good idea to make sure the valve is moving freely!!

Another quick test you could do is while the engine is running pull each plug wire off and note if RPMs drop noticeably, they should.. If pulling the wire off of #6 doesn't make a difference then I would do a compression test. Pulling the wires may be easier from the coil pack..

Here's a test that may help too,

2011 Ranger XLT 2x4,4.0 SOHC, 5 Speed Auto, 3.55 Rear. Oxford White.

Simplicity is the ultimate sophistication.

Torque it down till it breaks off, then back it off 1/4 turn.
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