Cold Plugs?

[Tom Mandera <tsm1@domain.elided>]

Arghh..

While the motor was out of the Scout, I put 8 brand new Autolite 85s in, 
after scanning through 4 years of Digests on "Sparkplugs".. 

OK, a week ago, Scout is running fine in town.  Take it on the highway 4 
miles @ whatever speed I can maintain.. starts missing, and the condition 
gets worse as I continue down the Interstate.  Even after getting off the 
highway, it was missing pretty bad.

The next day, I isolate the miss to #5 & #6.  I pull the plugs - crudded 
up.  All of the other plugs looked normal.  I can't say if the plugs were 
oil fouled, or just carbon and unburnt fuel..

Cleaned 'em up, reinstalled.. didn't run quite right.. but a day later of 
in-town driving, it was back to running on all 8 cylinders.

Monday or so I yanked #5 & #6 and replaced with 2 new ones (I had bought 
'em already).. plugs looked *fine* like the others did.  New Autolite 85s.

Yesterday the coil wire gave me some grief.. tonight I replaced the coil 
wire, and all 8 plug wires.  New Napa/Belden 7mm wires.  I goofed and got 
2 backwards, and drove to the movies with my 6cyl.. and made one loud 
bang on the way over.. ;-)

Got home, found the wires I'd crossed, runs like a top.

Motor's running strong.. I drive to Arby's for some dinner.. it's in a 
bag on the seat, I decide to take another highway drive.. maybe a bad 
coil wire/plug wires caused the miss, which caused the unburnt fuel to 
foul the plugs..

I come down the on-ramp in 3rd gear and tach it out.. grab 4th gear and 
start accelerating up the hill.. crest the hill, and before I'm even past 
the other Helena exit (1/2 mile), I start feeling a loss of power, and a 
miss.. I press on the full 3 or 4 miles to the next exit (Montana City), 
able to maintain 65, but not feeling right.. punch the acclerator.. it 
doesn't accelerate quickly.

Get off at Montana City, it's missing bad as I roll to a stop on the 
off-ramp.  Blip the throttle as I pull out and make the U to get back on 
the Interstate.. surging a bit as the a cylinder fires now and then.. get 
back onto the onramp, 3rd gear, nail the gas... slowly acclerate down the 
ramp and up the hill.. truck is swaying slightly from the unbalanced 
motor.. finally pull 4th gear and slowly get up to 65 for the drive back 
home.

Get off the Interstate, it's missing.. low power.. pops once or twice as 
it surges.. 

.....

I was reading in TechTalk today that the Autolite 85s I put in are a 
cooler plug than "normal" or what the books recommend for the Scouts.  I 
picked up the 85s on the advice of the digest many moons ago.

Do I need to step up to a hotter plug?  At *sustained* high RPMs it just 
won't keep firing.. but when I tached 3rd gear out on the on-ramp, and 
then stomped on 4th, it was pulling hard... then started missing.

I bet, if I wait a day, the miss will be gone and it'll be zipping around 
town again.. but I'd like to go for a highway drive and see what kind of 
mileage.. the 2300 has 63 (or 61?) jets at the moment, and there's a set 
of 58s waiting to go in once I get it *running right*.

-Tom Mandera, Helena MT
http://www.tmcom.com/~tsm1/scout