Newbie here. Thanks in advance for any response. I recently bought a 2006 F-150 with 4.2 V-6, 2wd. The truck has 41,600 miles on it and looks like new. However, on an intermittent basis, the engine has a strange shutter on start up and less frequently, on shut down too. At times, it takes two or three attempts to start the engine and that's when the shutter is most apparent. It shutters instead of starting. But, so far it always starts after two or three attempts. Most of the time, it starts right up on the first attempt.

I'd like to address this problem before it gets worse. I may decide to take it to a mechanic, but before doing that, I'd like to learn enough about this problem to discuss it intelligently with a mechanic.

Any ideas as to what would cause the unusual shudder would be appreciated. Again thanks for any ideas.

 

i would change the fuel filter and and run some sea foam through it... check air filter....

 

Thanks for the suggestions, Bobkyle2. I picked up enough BG44K today to treat a full tank of fuel. I read it is more effective than Seafoam or Chemtool B-12. BG44K is a lot more expensive than the other cleaners, but if it works, it'll be much cheaper than a visit to my mechanic. Then too, I'll have a clean fuel system - a very good thing in itself.

I was told there are two fuel filters - one underneath the truck in the fuel line and one in the engine compartment. Is this true? I'll change the air filter also and report back after a tank to let you know if it cures the problem.

Thanks again for the suggestions.

 

did you find anything on this? Mine does the same thing...a really noticeable vibration on start and shutdown.
Maybe the fuel filter and/or plugs/wires??

 

Nothing definite yet. At my last fillup, I added two 11 oz cans of BG44k. It's pretty expensive stuff, but is said/supposed to be better than Seafoam or Chemtool B-12. With only 1/4 of a tank used since adding the cleaner, the shutter has improved noticeably, but is still there on occasion. Did not change the fuel filter yet, but did replace the air filter.

If you positively find out what the problem is, please let me know.

 

do you have any check engine lights on??......

These motors make alittle vibration from the factory... due to the tune..they try to stay lean at idle....
Also i used Royal purple oil and a K&N oil and air filter..i beleive the oil made my engine change completly.. runs hell of a lot smoother

 

No check engine lights. Engine runs really smoothly through all speed ranges. No complaints there. It's just the annoying shutter at startup (not all the time, just occasionally). Even less frequently, I get a much lighter shutter at shut down. Not really enough to cause any concern. It's just that little things have a tendency to get bigger/worse on machinery. But, sometimes, they go away too.

It will be interesting to see if the fuel system cleaner works.

 

sure will
I ordered a fuel filter and plugs/wires from rackauto and will change as soon as I get them in...I'll also try some fuel additive but I don't think that's going to make a difference.
It may at first, but I see it coming back eventually....

 

Today, I changed out the fuel filter. It had a rusty looking few drops of fuel dripping out of it once it was off the truck. It will be interesting to see if the shutter goes away. Will report back as new information is learned.

BTW, I learned the fuel system on my truck has a fuel line check valve that circumvents the need to depressurize the fuel system before disconnecting the fuel filter. This prevents any spray. However a small amount of fuel, under no pressure, did run out upon disconnecting the fuel filter from the line. This meant I did not have to take any action prior to removing the filter. Also, I did not have to cycle the ignition key on and off a few times to repressurize the system. The engine started right up on the first try. Took all of 10 minutes.

 

haven't done it yet - where is it located?