My explorer just started to run a bit rough on idle. It has 110,00
burns no oil and is mint condition.
I bought some cheap copper core plugs and changed just one plug to see
how bad the old ones looked. Wow the old ones had a gap that was
huge, like over .9 they call for .54. I started the car with just
one new plug in and it idled great!
I'm thinking just how much better it would run with all six changed.
Insted of putting the cheap plugs in I decided to try AC #14 (the zone
said my truck could use #5 or 14, 14 is hotter I guess)
Anyway I gapped the rapid fires at .54 and put them in along with new
I start it up expecting super smooth idle, no way it idles like it did
before I changed the plugs.
I looked up the rapid fire specs and they say to gap at .60 on my car.
I gapped them at .54 as the manual says.
Could that narrow gap make it idle rough?
I tried to locate which plug was misfiring by pulling plugs off the
distributor. It was really hard to tell as it does not run that bad
on 5 cylinders.
So why is it idling rough?
1. One of the plugs is misfiring
2. One of the new plug wires is bad
3. The rapid fire plug are all misgapped.
The plugs that came in my truck are Motorcraft Platinum 42PG.
At first I purchased a 6 Autolite 765 copper cores. I put one
autolite in cylinder #6 and it idled super smooth. But that was with
the old plug wires.
I noticed the distrubutor cap has plugs on left side numbered
1left side 5 Right side of cap
Notice how they have #6 in the middle of 4 and 5 vs the left side
where they are in order. This may be just the way the cap is made.
but I'm thinking did I switch the wires?
Any help is appreciated. I don't want to pull off all the plugs if I
don't have to, I have bloody knuckles from the first time :)