Definitly something off about my car after the plug change

[CobraRed_96_GT]

Changed out my old autolite double platnums to some Motorcraft AGSF 32C's
well at first after install the car obviously ran rough at idle. So i figured it was the #4 wires I scraped and had to wrap electrical tape around patching the small tear. So i take that plug out and put it back in and put more electrical tape on it then see the #3 wire isnt seated all the way - pushed it in started the car, runs fine. I drove to my GF's house today and ran an errand and it seemed fine. Drove home tonight and gave it some real gas for the first time and above 3K is terrable, like a big drop in power and it feels like it's bogging or too much back pressure on the exhaust - a wierd feeling. Though the car runs fine belowe 2.5k and at idle.
Im stumped here, ill try putting in my old plugs tmw after work to see if that helps since i used the Motorcraft plugs out of the box-gap since i dont have a feeler gauge. Other than that i think it must be the SPW's though i have new FRPP ones comming. Any ideas as to what i can check?

 

[the98stang]

Your using electrical tape to okey-rig your car and your wondering why it's running crappy? Get that problem fixed first. Then replace the spark plugs with the recommended gap.

 

[CobraRed_96_GT]

Your using electrical tape to okey-rig your car and your wondering why it's running crappy? Get that problem fixed first. Then replace the spark plugs with the recommended gap.

well, i only fixed the scratch on the wire that was caused from taking the boot out with electrical tape cuz i know that im getting new wires next week. And the problem i experiance doesn't feel down a down cylinder, expecially since it runs fine at idle. Do you think the wire is short arching onto something else?

 

[Kilgore Trout]

Spark is probably jumping to ground on the rigged plug and causing severe misfire.

 

[Mike97gt]

it's probably those plug wires.

But you should try this, climb a hill at low rpm's in 4th gear ( 1500 or so) and see if it bucks.

 

[four six]

Get those new wires and check the gap on the plugs

 

[CobraRed_96_GT]

yeah, that's what i was afraid of.

 

[Kilgore Trout]

Plug gap can be annoying...

On my Cobra I got new Motorcraft AGSF12-FM1 plugs and gapped them at .035 but then I thought I could get more power by opening up the gap. It seemed that only people with increased boost needed so tight of a gap. So what the hell I opened it up to .050 and then got massive spark blowout and misfire. So I re-gapped at .044 and it seemed ok but then more spark blowout at WOT. So now I am back to .035 and it runs great. Needless to say, I am getting pretty fast at plug change. Also, since I cleaned the plug wells and COP boots each time they are damn clean now and seal perfect.

 

[thomas91169]

holy crap .05 is a huge gap for boost!

i use(d) .032 when i had my 03 cobra and i use .028 on my '90 GSX.

 

[Kilgore Trout]

holy crap .05 is a huge gap for boost!

Indeed

 

[CobraRed_96_GT]

You guys wont believe this, i ordered those FRPP plug wies yesterday online......came this morning in the mail. I paid for standard shipping which was like $9.
I'ma change em all out tmw. I just measured the gap on the old Autolites (with a flat feeler gauge, i know - i know) and it's gapped at about .048 - that's odd. Ill go and buy a real spark plug feeler tmw and gap the new ones correctly.

 

[CobraRed_96_GT]

ha, here's the problem. Just took out #1 plug and I measured it w/ the new gauge: .045. Must be cuz it's an AGSF plug for the 92 Ford engines, but it's worth having the extra threads. That mixed with crappy wires should cause some rough acceleration, LOL.

 

[thomas91169]

just cause the plug has extra threads doesnt mean anything since the head only has a certain number of threads.

 

[Kilgore Trout]

just cause the plug has extra threads doesnt mean anything since the head only has a certain number of threads.

Then why did Ford change the recommendation from AWSF to AGSF?

Anyways, this is a matter of debate probably best handled in one of the threads that already exist on it or in a new thread.

Read what the Bullitt Archive has to say about it

 

[CobraRed_96_GT]

just cause the plug has extra threads doesnt mean anything since the head only has a certain number of threads.

if you look at the standard threads on an AWSF they are about 1/4" long, where as the the head has about 1/2" of thread depth from what i can see.
Anyways, I must have needed wires before or the gap on the autolites at .047 was really effecting because now w/ the new FRPP 9mm wires and AGSF-32C's at .054 it runs actually way smoother under power - im not just imagining things - pretty awsome