Stock: SP Gap .40 or .54??

[madonionrs]

Spark Plug gap, 1989 Mustang .. stock

 

[93tealstang]

Anywhere from .52 to .56 should be ok.

 

[p.exeter_bleu]

if i remember i think its supposed to be .58?

 

[madonionrs]

Thanks guys!

This is probl why my car is idling like hell, I have it at .40 with no dielectric grease.

 

[FoxChasis]

Stock gap is .054".

And you don't use di-electric grease.

 

[madonionrs]

Stock gap is .054".

And you don't use di-electric grease.

What ?
I thought you use anti-seize on the end that goes in the block (threads)
Then di-electric grease on the tip that goes into the spark plug wire.

 

[TattooMatt]

What ?
I thought you use anti-seize on the end that goes in the block (threads)
Then di-electric grease on the tip that goes into the spark plug wire.

That is correct. Stock recommendations for gap in my 93 operators manual is .50-.54

 

[p.exeter_bleu]

ah crap, i was told .58 does the year make a difference? what should i be gapping my 89 at?

 

[madonionrs]

You should use di-electric grease on the tip of the plug that goes into the wire boot, correct?

 

[ram360]

You should use di-electric grease on the tip of the plug that goes into the wire boot, correct?

You should. If you buy new plug wires it already has it in the boots.

 

[5spd GT]

So what happens if you don't put the dielectric grease on when you change plugs...(stayed with my 9mm FR wires)...should I take the wires off and apply some grease to the ends...I just recently put in Autolite 25's gapped at .054...

In short what happens if you don't put the grease on the ends?...

 

[Luvmy88]

Would adding an Accel super coil call for an increase/decrease in plug gap?

 

[TattooMatt]

I'm pretty sure that the gap would be the same for an 89. It's the same engine there are only slight differences between them. .50-.54

If you don't use di-electric grease you will have a chance that the plugs could arc. It's basically an insulator and a water shield. You'll have an easier time getting your wires off the plugs next time if you use it too.

 

[madonionrs]

Btw, are you supposed to just put a thin layer on.... or put a good swab of it on the tip.

 

[TattooMatt]

Btw, are you supposed to just put a thin layer on.... or put a good swab of it on the tip.

Just make sure it's covered pretty well. I don't think that it's a super accurate procedure. Just put enough so that the wire won't seize on the plug after some damp weather.

 

[FoxChasis]

My mistake....thought you were talking about the threads. I totally forgot about the plug wire-to-plug connection.

If I remember correctly (I'll have to get into my Motorcraft spark plug catalog later to confirm), all H.O. 5.0L Mustang engines except the '86 model year spec'd a gap of .054". The '86 model year H.O. 5.0L Mustang engine spec'd a gap of .045". (The plugs were unique for '86 as well.)

 

[5.0guy]

yeah, I've been wondering about this too--if anyone has a stock car, with the coil cover, look on that, mine is messed up and I couldn't read it. I'm runnin around .04 gap--I think..

 

[cevtv]

Actually, it's .044" up until 1990. 1991 to 1993 is .054". They used a higher ouput coil starting in 1991.

 

[iwashmycar]

Would adding an Accel super coil call for an increase/decrease in plug gap?

Not sure if this Q was answered yet....
I'd like to know also?

 

[cevtv]

Well, if the factory opened the gap when they went to a higher output coil, then it makes sense that you could open it a bit with a higher output Accel Supercoil.............