hey ya'll! first off i want to thank everyone for all the help on my last post. it ended up being the relay. i have a 91 f250 and it starts great all year round without plugging it in. the 1989 i just bought runs super but does not want to start at all. i went thru and replaced some of the glow plugs. i was told in 91 they changed the glow plug setup. does anyone know if this is true? if so do they sell an upgrade to help the engine start. the 89 is a crew cab long bed with a manual tranny and an ats turbo. so i thank u now for any help u can provide...

 

The 89 should have the newer style gp's.

 

try replacing the return lines and make sure your batteries are at least 850 cca. change the fuel filter and have the starter checked if nothing else.if its not spinning fast enough it will be a bear to get going.you may try running jumpre cables from one truck to the other when the motor is cold and then try to crank it up.or swap batts.and have you checked all the glowplugs?

 

Glow plug systems changed to the new style system in 87.