2001 4.0 sohc missing

[John H]

I have replaced bosch plugs with NGK,replaced dpfe sensor because of code,replaced wires with 8mm borg warners. It misses most while cruising around. It doesn't seem to do it at wot,and might get a miss every now & then at idle but not constant. no cel on either,I was considering changing the EGR solenoid but wanted to ask for suggestions first.

 

[AllanD]

When you've eliminaed plugs and wires what is left....

Frankly I'd be thinking about borrowing a known good coil pack from a friend.

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[John H]

update

Replaced the ngk plugs with motorcrafts due to the pistons hitting the ngk's. Since the motorcrafts were put in i took it to my mechanic 3 days later because it was still idleing rough & missing,he installed new wires & plugs at that time since my friend who put the motorcraft plugs in messed up a plug wire. I put a new coil pack on as well & the mechanic fixed a vacuum leak it idles a little smoother but not much,still has a miss at idle & driving. any other ideas? I have tried a maf sensor from an 01 explorer no change. Considering new Iac since it idles around 500-600 after its warmed up.

 

[Bob Ayers]

Do a compression test next......

 

[Fx4wannabe01]

^^ditto.

Remember...these 4.0L SOHC's aren't known for having a smooth idle in the first place.

Did you just all of a sudden start having issues? OR did you do anything engine related just before these issues?

 

[John H]

well the missing started back when i put the bosch plugs in,the low idle was all of a sudden.

 

[wahl_7s]

Do a compression test next......

X2...Don't ever put anything but Motorcraft plugs in a SOHC!!! I've tried other plugs and they don't work PERIOD. Kragen sells Motorcraft Know 4 or 5 bucks each. It's not worth a dollar or two to change brands even higher priced brand. JUST SAY NO !!

 

[Big Jim M]

Hmm!

well the missing started back when i put the bosch plugs in,the low idle was all of a sudden.

Ok So what could you have done incorrectly when you swapped in the wrong plugs.. Could one or more of the plugs have the wrong gap? Could one or more of the wires have been crimped and lost their conductivity?
Could you have swapped two wires? Could you have pulled a vac line loose? Could you have pulled a lectric wire loose?

Always use the factory motorcraft plugs.. If ngk or others were better Ford would have used THEM!

Spark plugs MATTER! None have had the testing that the motorcraft plugs have had. ALL aftermarket plugs are either a bit too cold or a bit too hot from the exact motorcraft you need.
Big JIm

 

[Fx4wannabe01]

A cheaper alternative is using Autolite. Aren't the Motorcraft plugs manufactured by Autolite? I'm currently running Autolite APP5144's in mine since finding a cracked motorcraft in my new engine.

 

[Bob Ayers]

A cheaper alternative is using Autolite. Aren't the Motorcraft plugs manufactured by Autolite? I'm currently running Autolite APP5144's in mine since finding a cracked motorcraft in my new engine.

No, Motorcraft and Autolite are both made by Honeywell, an Allied Signal company. They are, however, manufacturered to different specifications.

 

[Big Jim M]

Guys since the motorcraqft plugs will last more than 100,000 miles in a fuel injected 4.0.. Why on earth would anyone worry about the price? ALWAYS get the exact correct plug for your ride.
Big JIm

 

[98 ranger xlt]

Get rid of the Bosch plugs they do not run good in the 4.0's

 

[Fx4wannabe01]

Guys since the motorcraqft plugs will last more than 100,000 miles in a fuel injected 4.0.. Why on earth would anyone worry about the price? ALWAYS get the exact correct plug for your ride.
Big JIm

Hate to give this to ya Jim but guess what? Reccomended service intervals are not always correct. Mine were toast by 70k and not gapped properly from the factory in the first place.





Only Motorcraft or Autolite. Everything else runs like shit.

 

[Bob Ayers]

Hate to give this to ya Jim but guess what? Reccomended service intervals are not always correct. Mine were toast by 70k and not gapped properly from the factory in the first place.





Only Motorcraft or Autolite. Everything else runs like shit.

The recommended service intervals are based on no other failures. If something happens that causes the mixture to be lean (as an example)
the plugs will be "toast" in no time.

 

[John H]

Update

Got frustrated with it took it to the dealer today & they found code p0304,even though no cel & #4 spark plug was cross threaded. they fixed the threads installed new plug & it is smooth again. Thats what I get for asking a friend to put the plugs in for me.