autolite double platinum misfiring

[tk1251k]

Had a small miss in my 94 ex so I decided to install autolite double platinum. Checked the gap on the new plugs which were around 45 so I set to 54, It is missing alot worse than before . i am pulling these autolites out today and putting the old ones back in. Are the autolites supposed to be gapped? I have read alot of variations on this with no definitive answer yet as to gap the plugs or not. thanks

 

[Roadrunner777]

I can't answer your question, I have never seen spark plugs discussed to the degree that it has here, I'm sure you will get some good opinions shortly. But, opening the gap increases the voltage of the spark, and may have caused a breakdown in the wires or coil.

I wanted to ask you what the old plugs were, and how they worked for you.

 

[tk1251k]

Old plugs were motorcraft. Had a small miss seemed worse under load. I did notice the 3 drivers side plugs were quite a bit more worn than passenger side. I read some posts somewhere else on here about that being common on explorers.

 

[techieman33]

Is it just one cylinder misfiring? I was fighting similar issues a couple weeks ago and after hours of swapping parts it turned out to be one of my new motorcraft plugs was a factory dud. If you can determine which cylinder is misfiring then just replace that plug and see what happens.

 

[gmanpaint]

54 is the correct gap. I agree with Techie also.

 

[tk1251k]

I just got thru checking coil as best I could for ignition. I unclipped all six plug wires at coil and started engine and picking up each wire at a time to check for spark. The two on the back not much ignition at all. One no fire but it did cause miss when I moved it away from coil.I know thats not the best way but it tells which coil wire has fire to it. Would that indicate coil bad.

 

[Roadrunner777]

Edit: I had described a test method that works for distributor-based systems, but not on DIS coil pack systems. The better method is described in later posts.

 

[tk1251k]

Yea I tested all six at the coil with the back one showing no fire right side. When I checked for firing at the plug seemed ok. So not sure yet if the coil is the culprit or not. I would think all coil wires would surely have the same continunity at the coil.

 

[jd4242]

If the back right one dint fire at the coil,then the back left one would fire either.there is three coils in that pack.back two plugs sharing one coil,middle two sharing one coil and the front two sharing one coil.sounds like wires.also autolites suck,go regular old ngk

 

[tk1251k]

If the back right one dint fire at the coil,then the back left one would fire either.there is three coils in that pack.back two plugs sharing one coil,middle two sharing one coil and the front two sharing one coil.sounds like wires.also autolites suck,go regular old ngk

Would no arc at coil indicate a bad plug wire? The back left wire does have some arc at the coil but right side none.I guess I need to switch wires around and check for a bad one I think.

 

[jd4242]

How was you testing it?by slowly pulling the wire off?if so the yea a plug wire can be bad,if the wire isnt making ground at the other end then you wont get an arc

 

[tk1251k]

How was you testing it?by slowly pulling the wire off?if so the yea a plug wire can be bad,if the wire isnt making ground at the other end then you wont get an arc

O.K. so you mean if the wire is bad and not grounding at the plug then there will be no arcing at the coil. I just set the wire loosely on the coil and hold while es is running and slowly move it up or down at the coil to check the amount of arcing.

 

[jd4242]

Yep if the wire is bad it wont arc

 

[tk1251k]

Yep if the wire is bad it wont arc

Thanks alot jd you are correct. THe wire on the back side left was bad although it had alittle arc it was split at the plug boot. THe wire on the right side had no arc is fine. I think its solved anyway the miss is gone fixing to take a drive. I do appreciate your time helping me out I will inform agin when I get back . thanks

 

[huntman58]

How you tested the coil I would do the same at the plug end also if the same plug gets no spark but dose at coil then it’s a wire. You can also take an ohm meter to the wires and check them that way also.

When you changed plugs did you also change your wires? If they are older wires there is a good chance that one may be broken inside of its self.
I do know that these motors do not seam to like any thing but MotorCraft or Autolight plugs or wirers. I have personally tried many other brands and have had nothing but problems with them from early burn out to just bad running from the get go.

also if you still have the old plugs try this put them back in for this test and then take one easy to get to wire and put it on the new plugs one at a time with the plug grounded on its side e and see if it is firing if all 6 fire then again most likely wires if one is not then bad plug and yes even a new plug can be bad. Over the years I have had that happen a few times also. So before blaming the plugs test them and the wires first instead of throwing more money at it.

 

[jd4242]

Autolights suck!!these motors dont like them! NGK or Motorcraft!!ps so does Fram!!

 

[techieman33]

autolites are fine, they make the motorcraft plugs. Autolite and motorcraft are the 2 most recommended plugs on the site.

 

[tk1251k]

Dont"t know about much about platinum autolite plugs but I have run the cheap copper autolites in other vehicles with great results. However the motorcraft plugs in my ex right now over 75,000 miles look great cleaned them up gapped them and it runs great. The boot as I mentioned had a split in it at the plug but never saw in arcing there guess it was enough to cause a no fire on opposite side.

 

[FIND]

I have autolite iridiums gapped to .062.... They work fine for me.... Motorcraft plugs are basically just rebranded autolites anyways.

 

[jd4242]

i was told that motorcraft and autolights where the best for this motor and i went through 2 sets and have heard of other people having a miss issue after a couple of miles.i will only run NGK for now on,thats what i only have ran in any of my other performance vehicles.just my .2 cents though

ps i run NGK Tr6 gap to .34 soo