Tgmcdowell

I have a 2001 ford f150 with less than 170000 miles on it. It started doing a stutter when I'd drive 45-60mph and then started getting worse. I took it to 2 shops to get it looked at both said Intake Manifold Gaskets need replaced so we replaced them along with the Mass Air Flow Sensor, Oxygen Sensor OEM Sensor, Spark Plug in Cylinder 1 and fixed 2 Vacuum Leaks. They had the truck over a week. I got it back it ran wonderful for 2 days and then started stuttering again and the service engine light came back on. I then took it to Auto Zone to have them give me the code it pulled from the computer. It said Misfire on Cylinder 1 so I bought another spark plug put it in the truck and truck ran fine for another 2 days them right back to stuttering and missing out. I don't have any oil or water in the cylinder spark plugs are not fouled or burnt on ends. Does any one have any idea what can be causing this issue? I'm tired of paying out my rear and nobody being able to actually fix the issue. Oh and by my wording I'm sure you guess I'm a female and know very little about vehicle chit chat or engine issues. But I'd really appreciate any advise I can get at this point..
Thanks so much,

bobkyle2

I'd replace all plugs and wires...

Tgmcdowell

I replaced all plugs and wires made no change its still missing and stuttering except now we get some what sounds like back fire coming from underneath the truck.

Millers1504x4

Coil pack issue? I havent had a lot of experiacne with Ford but a Dodge I had an experiane with once I got it up to 50-60 mph the engine light came on a nd kept flashing at me. So I took it home and drove ym car. I later had it at a mechanics to find out it was the fuel pump regulator. Sounds similar to what your saying with the stuttering such at 45-60.

Tgmcdowell

Ok this is what has been done as far as trying to fix the stuttering or missing of the vehicle.
Plenum Gasket replaced
Intake Manifold Insolator Bolts ad Grummets replaced
Mass Air Flow Sensor replaced
All Spark Plugs and Wires replaced
Now after replacing all that it's still missing and stuttering. If I punch it or turn on over drive it will stop doing it. Does anyone have any other suggestions before I go and spend another life savings by putting it in the Ford shop?

Tgmcdowell

They said the coil pack was good..

dr_bowtie

I'd probably post in the correct section to get the best help...jus sayin

Islanddevilca

Hi all..I am new to this site and forum and not sure where to post . but found this thread and have the same problem with my 4.2 misfire etc.. have done lots of research and spending. but no answers.. does anyone know how to fix this issue. Thank you

bobkyle2

Start your own thread. As things between 2 different trucks are different.

papa tiger

1. Do a cold and warm compression test. You are looking for a bad valve possibly. Also (2) check your electrical connections back to the PCM/ You are looking for a corroded, bad connection/broken wire/ wire rubbing metal. (3) check your fuel pressure. You are looking for very low fuel pressure/ bad electrical connection/ground. Look closely to the areas where the wire joins the loom in all cases.

Since you change a spark plug and it runs great for a couple of days pull the coil and visually inspect it closely for obvious damage. You can test it with a VOM. Also the connections to it for damage. Obvious ? Simply replace it with a good one. Next is the injector and its connections. This is probably electrical in nature, I have heard of front crankshaft problems but the timing there is usually perty catastrophic damage to the pulley.