edis? help

[mr_happy]

Hey. First post and I am wondering.g what the lifespan is of the edis system and what are symptoms of a bad edis. Thanks. I am pretty sure mine is going. My truck misses quite frequently. Sometimes and other times it is good. Just did plugs wire's and seafoam to stop the pinging. Also did fuel filter and oil change .But it still misses?

 

[adsm08]

I would suspect the coil before the module. Modules are not considered wear items and are usually either there or not, not in between like you describe.

 

[Snoranger]

what are symptoms of a bad edis?

The truck doesn't run.

 

[UrbanRedneckKid]

Not necessarily true...

I've diagnosed and replaced quite a few ECUs that weren't grounding individual coil or injector circuits.

But as said before, go to the coil first, It's waaaay more likely to fail before the ECU.

BTW, if your into upgrading, Accel makes an awesome performance coil pack.

 

[RonD]

My '94 4.0l was missing and new plug wires fix it, 18 year old plug wire failed???, they just don't build them like they used to
And it's very important to use motorcraft spark plugs in the 4.0ls, it eats other brands and will miss like crazy.

A failing coil will usually turn on the CEL(check engine light) but not always.

The Ford coil pack can be tested with an OHM meter, there are a few How To videos if you google it.
Google: How to Check an Ignition Coil Pack the easy way

My '94 has 300k miles on the factory coil pack

Also an easy thing to do is to mis-wire new plug wires, check here for the correct wiring on the coil pack.
http://www.therangerstation.com/tech_library/4_0_Page.html

It's
4 6 5
3 2 1

the 4 6 5 is the one I messed up

Another thing that causes missing in the 4.0l engines is the MAF(mass air flow) sensor.
Have a read here:
http://www.therangerstation.com/tech_library/CleanMAF.html


Pinging could be a sign of a lean mix, or an EGR system issue, these should also turn on the CEL