I bought this 95 F-150 with a 302 5 speed about 1 year ago, after getting it home I went threw her and replaced plug, wires, fuel filter, fluids, etc. Six months ago I gave the truck to my mother who is well deserving of it. Recently she has been insistent that the truck is running rough and the MPG is getting worse.

Well this weekend I got around to checking things out. First thing I did was pull the plugs for inspection. Now I specifically remember gapping the plugs (Motor Craft SP450) @ .054 but when started checking them only one was set @ .054 and the rest were between .044 - .050

My mother who is even more hard headed than I am called to get the gap spec from her "AutoZone guy" and was told the gap for that spark plug was
.044 so from that point on she wouldn’t listen to anything else. I had to prove to her that the gap for that plug was .054, so I went to Motorcraft.com to look it up. According to motorcraft the gap should infact be .054. Of coarse she would not believe what she was seeing with her own eyes thought the web page was wrong. This brings me to the point of this thread... Sorry for the long background story.

We decided to "survey" other auto parts dealers for the proper spec and to my dismay half of them said the gap was .044 and the other half said .054. I couldn’t believe my ears how could it be? WE called AutoZone (.044) Advanced (.054) and Pep boys (.044) and 2 dealers (one said .044 and the other said .054)

So two questions...what is the proper gap for a Motorcraft SP (SP450) and WTH did the gap change. There are less than 6000 miles on her since I bought that truck, the plugs look practically new.

Thanks!

 

the gap is posted on the sticker under your hood.

 

according to my chiltons manual, every engine from 87-96 were gapped to .044.

 

Looked for it...
couldnt find it.
Buout all there is, is a Wire routing diagram.
Also I was told on by many in my phone calls that different plugs have different gap specs. So an Autolight vs and Motorcraft (might) have different gap specs.

this is where its published on motorcraft

http://www.motorcraft.com/catalog.do

 

the plugs are to be gapped to the same specs. like i said my chiltons manual says all the motors from 87-96 were gapped to .044.

 

then again specs have changed since these trucks were made. i'll have to look into it a little bit.

 

alright i didnt have to look far. the gap is clamed to be .054 now no matter what plugs you run. when you gapped the plugs, did you make sure you were able to slide it up to .054 on the gapping gauge without any extra force? fix the gaps and see if it runs better. sorry about the problem earlier.

 

Like mentioned above, stock gap is 0.044. Don't increase the gap unless you upgrade the ignition componenets to warrant the gap.

 

The decal under the hood of my '93 with a 5.0 and AOD sez .054!!!!!!!!!
I'll go with that before any thing Chilton's sez!!!!

 

Motorcraft gap secs.for a F-series EFI 302 w/ the N - engine code in vin #(meaning is your 302 EFI a 302 EFI I guess). changes from .044 for 87'-88' then 89' gap for 302 EFI When clicking on specifications changes to .054!(w/ disclaimer directing owners to disregard if info differs w/ info stated on vehicle decal /manual. Which lead me to a couple of ??'s. Are there stock 302 starting in 89' and/or later that has it's stock ignition operating w/.054 it's stock gap. If so, what the hell happened from 88' and 89' ?

 

Well it is snug, and would not move any further past .054... geting it there does not require forcing it. Id like to add im using one of those round or coin shaped tools to gap the plug.

 

I will have to wait till i get home to check the engine code, can i find that on the door sticker? Or anyone know what digit in the VIN the engine code is? If its the 8th digit from the left the my engine code is "N" that the only N in the VIN btw... that must be it.

 

The spark plug gap on a 1995 "N" 5.0 engine is:
Gap .052-.056
Plug Type ASF-42C.

Any other information is wrong and do ask a parts countern man, they know less than you.
Do trust any after market repair manual on specifications.






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Thats great information, Thanks!
Of the two pictures I only have the bottom one on the truck, where did u get the hoodlablebig.jpg? Is that from a service manual? Is it on your truck? If so where abouts is it?
I looked up the ASF-42C plug on motorcraft.com and am now curious to know what is the difference between the ASF-42C. and the SP450, if any.
Anyone?

 

It is identical to the one under my hood but the image is from the FORD site below. I used the calibration number off my door, 4-54E-R10 and this very well may be the calibration number for your truck.

To get information on a truck just use your calibration number and it will give you what I posted for your truck plus all of the part numbers for your emission parts and vacuum diagrams.

You can check it out for yourself to see if any parts changed by going to the Motorcraft.com site,
http://www.motorcraftservice.com
then click Quick Guides on the left,
then scroll down and click VECI Labels,
then put in Year
then vehcle
then engine
hi-lite your Cal #
then click “VIEW CONTENT”

You can then look at the different items for your truck.