spark plug gap

From "The Official Ford Mustang 5.0 Technical Reference & Performance Handbook 1979-1993" Ford Racing Part No. M-1832-Z4

Page 274
"Spark Plug Applications" table
Year---------Engine--------------Motorcraft number-------Gap (inches)
1979---------5.0L (49 state)-----ASF-52------------------.050
1979---------5.0L (california)-----ASF-52-6---------------.060
1980---------4.2L (all)-----------ASF-42------------------.050
1981---------4.2L (all)-----------ASF-52------------------.050
1982---------4.2L (all)-----------ASF-52------------------.050
1982-1985---5.0L carbureted-----ASF-42------------------.044
1982-1985---5.0L CFI------------ASF-52------------------.050
1986--------5.0L H.O.------------ASF-34 or 44------------.050
1987-1993---5.0L H.O.-----------ASF-42------------------.044
1993--------5.0L GT-40 (Cobra)--AWSF-42C---------------.050

1. Factory electrode gap specifications are shown on each Mustang's VECI label that is affixed underhood. The relatively wide gaps specified created the fat, long-duration spark needed to ignite the lean mixtures prescribed for most normal operating conditions.
2. Most non-Cobra 5-liter motors typically run well with spark plugs gapped at .052 inch. For normally aspirated engines in high-performance service, a plug gap between .040-.045 inch is suggested by many tuners. Those same sources also suggest .028-.034 inch in turbocharged, supercharged, and nitrous-fed five-ohs.
3. Some 1993 GT-40 Cobra motors were factory fitted with colder, AWSF-32C spark plugs.

I have never gapped a plug. Every one I have bought and checked was close enough for me. So I buy them and toss them in!

Why does my book say 054?

Yup, rite here. 87-93 = .054

Whats your fuel pressure? Ever change your fuel filter? It could be, whats your timing at? Are the wires in order?(Firing order)

Anyone else gap at 054?

ryan218 said:

i gaped them at .050...runs a little better but when i go to give it gas it bogs backfires ever once in a while...im stating to wonder if the timing is off some..it will idle perfect for about 2 seconds then the revs will start going down and down then will either stall if you let it....or rev it and it will come back up if it dont bog...

what should i try next to get this thing to run better?

Click to expand...

Didnt you say there was 7 year old gas in it? That may be the culprate

LOL,, 7 year old gas? The filter is clogged!

ryan218 said:

fuel pressure......hell if i know....

fuel filter...i have a new one sitting on the work bench..where is the filter located at? is it in the tank or?

timing....no idea...

wires...yes....

Click to expand...

Its not in the tank. Its on the outside of the tank rite against the outside of it at the front part of the tank. You have to take off the cover then take off the crazy clamps. At least thats where it is in my 93.

Do ALL the tune up stuff, easily knock that off the list. If the problem persists then you have a few things checked off the list. Id say new pump, filter, maybe even injectors, AFPR, new coil, wires, plugs, rotar, cap, to start. Might cost a little but a car thats been sitting NEEDS this stuff to be done! Get her running right before you ever throw a mod at it. If you start modding (Im talking any mods) before it runs right, you might never find the issue!