MAF sensor

[wagonmaster69]

Can a MAF sensor cause a engine to miss?
99 explorer 4.0 ohv.
Other then plugs, wires and coil pack can cause an engine to miss and shake?

 

[BrooklynBay]

Are there any codes?

 

[EB4X]

NO...
MAF issue symptoms are bucking, hesitation but not in a pronounced way like a miss.. ...start with plug wires / plugs...

 

[BrooklynBay]

Maybe the CPS has an issue?

 

[EB4X]

Aside from checking all plugs / plug wires.... Pull out #4 plug and smell for coolant (and then #3).....I've read the head is known to crack near it on the ohv's if they're overheated...

 

[Turdle]

low fuel pressure or clogged injectors.

 

[MrQ]

Are you just looking for a CEL for codes or have you actually hooked it up to an advanced reader? There are codes that pop up but take a while for the PCM to "confirm" there is a consistent problem before a CEL shows and it sets the code.

Fuel pressure is definitely a number one contender for lean/missing/rough idle after plugs and wires. Get a fuel pressure tester, hook it up to the rail and look for greater than 60 PSI at key on/engine off. If it's low, change the fuel filter and test again. Still low your fuel pump is going bad. (Another indicator of a bad fuel pump is when you turn the key off after building pressure and see it leak down very fast)

Vacuum leaks can also cause this problem, but you would usually see a lean code pretty quickly.

 

[rasouth]

I had a similar problem with my '96 4.0, bucking, missing, hesitation. My plug wires were not routed properly. One of them was laying across rocker arm cover and shorting out. Make sure all wires are clipped into those little plastic clips around the covers.