Hey so I am having issues with setting the timing on my 1993 f250 351w efi. I am unclear as to when the timing should be read. My question is that at idle with the spout plug out what degree should it read? Some people have told me it should read zero, which is what it reads now, but online I have seen a lot of people say that at idle it should read between 5-10. Any help would be appreciated, thanks

 

Ten degrees BEFORE Top Dead Center. !0 degrees advanced with the spout removed is the recommended setting.

 

10 BTDC is the book setting, you can go as high as 16 BTDC with higher octane fuel. Regardless, if you get spark knock it has to be retarded.