GALE/FRED..the missing is violent and worse under full power demands...but always there...at my 2nd fill up no 89 octane so I put in 13 gal 87 and 30 gal 93.....I figured hardly anyone buys ethal so I got water in it....In my station I checked the tanks for water every day but most don't. anyway,Iam in COE park in ARK and plan to be here 6 weeks so Iam not desperate yet...But I still have to get this 11 tons 650 miles home. Starts easy, low speed Ok.......Its like a broken wire somewhere that's striking contact...now and then. Motor is solid ,having a valve job 5,000 miles ago. Burns no oil, 150 PSI in every cylinder....strong and solid ...I'll investigate in the AM. and BTW....there is no check engine light with such a bad miss....that's why if I don't get any codes with my scanner in the AM Iam going to take it to Ford. What the H does it take to throw a light??????