small hesitation after plug change???

[UnderdogGN]

ok well today i did a cap/rotor change and put in new plugs. It used to have motorcraft plugs that were one range hotter and i just put in new autolite 25's gapped at .058. Now in first gear when floored it will give a slight hesitation until 2800 rpms or so....any ideas??? is that normal??
thanks

 

[stangbear427]

Well, my bolt on GT has a screamin hot coil, big wires and a dynamod ignition module, and I only gap my Motorcrafts at .042... not saying that's it, just an observation.

 

[LX302]

Check your wires. One might be loose, or arcing. Also recheck your firing order. You might have swapped wires in one instance.

 

[stangbear427]

Check your wires. One might be loose, or arcing. Also recheck your firing order. You might have swapped wires in one instance.

In my experience, those things all caused a bad miss, lurching/bucking, not just a hesitation. Should be checked anyway though I suppose... who knows?

 

[UnderdogGN]

ok well i know for sure the firing order is correct. I noticed the plugs i took out were gapped in the .040's. The car has an MSD 6AL ignition, blaster 2 coil, and FMS plug wires if that makes a difference. The problem is no big deal its hardly noticible i was just wondering.
thanks

 

[stangbear427]

You sure it wasn't doing it before?

 

[HISSIN50]

Will it do it at idle?

 

[RaceDvr50]

You did compare the plugs side by side for length right? I'm wondering if you might have a slightly shorter plug. With the 6AL you should not see any hesitation because of spark unless something is wrong. Also is it possible that the wires are rotated one position off on the cap? With the 20 degrees of fire that the 6AL gives it could be possible but if you disabled the 6AL the engine would likely die.

 

[Mustang5L5]

0.058" is slightly too big. You might be misfiring due to the large gap.

You want to back it down to about 0.054". Yeah i know it isn't much, but unless you have a stronger ignition you could be having probs jumping the gap.

Also, buy some dielectric grease and coat all the wire contact points (on plugs and on cap and coil)

 

[UnderdogGN]

well im positive it wasnt doing it before. Im almost positive all the plug wires are in the right spots. There is a posibility that one of my plug wires isnt all the way on the spark plug though. If that isnt it, ill try shortening the gap a bit but the back plug on the passenger side is staying in, there is no way im going to try and take that one out again lol.
thanks

 

[Insane3D]

I'm not sure if this changed by years, but the stock gap on my '92 GT according to the sticker on the coil cover is .052 - .056. .058 is a bit over...but not too much. I just put in some new Autolite 140's in mine (GT40X heads) and I gapped them to .060, and it's been working awesome.