Have 91 Accord intermintly stays in limp mode, have pulled TCU and replaced capacitor and resitors, worked fine for a while almost a year and then started limp mode intermintly again. Has anyone experienced this and any recomendations for correcting this problem? What about the VSS(?) and speed sensor could this also produce this simpton?

 

Are you getting any codes? That would be the first place I would start? Better than guessing, IMO.