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kendall221
01-04-2008, 01:41 AM
About 3 years and 35,000 miles ago, I replaced the AWSF34PP spark plugs in my '95 SC with the Motorcraft AGSF34FM plugs because I was unable to find any of the 34PP plugs. Recently, I had a miss under acceleration which was traced to the ignition system. When we pulled the plugs, I found that the ground electrodes on the AGSF34FM plugs were worn to the point that the gap was about 0.065" on all of the plugs. I had gapped them at 0.054 when I originally installed them.

Needless to say, I find no fun in changing the plugs in this car, and went back to the Motorcraft 34PP plugs that I found as NOS. Hopefully, these should last the 75,000 miles like the other sets of 34PPs that I've installed.

David
'95 SC - 5 speed

Ben999_
01-04-2008, 01:52 AM
A good replacement for the stock plugs are the Autolite APP-764's and they should be gapped no more than .050". XR7Dave has posted some good info, check out the links.

http://www.sccoa.com/forums/showpost.php?p=637292&postcount=7

http://www.sccoa.com/forums/showthread.php?t=89983&highlight=spark+plugs

KwikGSeX
01-04-2008, 04:23 AM
I would change over to NGK TR55's like the Cobra's do..

SuperCharged91
01-04-2008, 08:45 AM
I just recently installed 34PPs no problems

S_Mazza
01-04-2008, 07:49 PM
If you use platinum plugs, make sure that you get the DOUBLE platinum ones, as each cylinder bank wears one electrode more than the other (hence needing the platinum there). Ford saved money by using different spark plugs for each side with platinum on the proper electrode only, but the replacements should have both platinum electrodes so that you don't wear one out more quickly. With Autolite, I think that one P is platinum and PP is double platinum.

kendall221
01-04-2008, 08:24 PM
S_Mazza
SC Newbie
SCCoA Member #: 2821
Member Page Join Date: Jul 2003
Location: Eastern (nee Western) PA
Posts: 1,213

If you use platinum plugs, make sure that you get the DOUBLE platinum ones, as each cylinder bank wears one electrode more than the other (hence needing the platinum there). Ford saved money by using different spark plugs for each side with platinum on the proper electrode only, but the replacements should have both platinum electrodes so that you don't wear one out more quickly. With Autolite, I think that one P is platinum and PP is double platinum.
__________________
God bless!!!

1990 SC auto ... red outside, gray cloth inside ... ~140,000 miles (and climbing) ... driven daily


Yes, I knew about the original plugs that Ford installed, and the need for double platinums. At the time, my understanding was that the AGSF34FM's were the direct replacement for the 34PPs. They're not double platinum like the 34PPs. Just want to point that out, so others don't make the same mistake that I did. The 34FMs will work fine, but you will end up replacing them sooner. Some people recommend that anyway, but I have better things to do than change spark plugs all the time....I'd rather only have to change them every 75,000 miles.

David
'95 SC
5-speed

fturner
01-05-2008, 02:33 PM
If you use platinum plugs, make sure that you get the DOUBLE platinum ones, as each cylinder bank wears one electrode more than the other (hence needing the platinum there). Ford saved money by using different spark plugs for each side with platinum on the proper electrode only, but the replacements should have both platinum electrodes so that you don't wear one out more quickly. With Autolite, I think that one P is platinum and PP is double platinum.

Ok now that is something I never knew about our cars :confused:. I know our cars use a waste spark that fires the spark plug the opposite way (in respect to what electrode becomes negative) during the exhaust stroke as well as the normal way for the comprssion stroke... hence the reason for the double platinum's because of the reverse firing.