bad glow plugs?

try checking one or both of the batteres could be on the way out, which cause the engine to turn over slowly.

i just replaced the batteries about feb-march this year

ok, well sadly your best bet is to take it to a ford dealership thay can hook it up to a scanner and do updates as well as find codes that may have not tripped off the check engine light.My truck wouldnt satrt one morning so i had it towend in, no light on or anything and they checked it and it came up with a injector control module for a 1000$. truck works like a million bucks now. i hate the dealer but there is the rare occasion that its handy when thier there good luck with your problem

you could also try checking to make sure the cables are tight and as well re check the battries if only one is going down it will cause a simmilar prob as yours good luck

y are ya using the glow plugs in the summer anyway. Glow plugs are meant to aid in winter starting. hell my gramps tractors start better than my mom's POS potiac van with out using glow plugs or either spray. run some diesel injector flush through your tank and if it does nothing then have your starter looked at

try replacing the starter, glow plugs and idm ( injector driver module) if not that then take it to a mechanic and let them deal with it :)