98 6.5 gmc starting issues
 

my friend has the same truck as mine only a gmc , his truck doesnt wanna start , ive changed: glowplugs, glowplug relay/ solenoid, fuel filter, fuel shut off solenoid. tested lift pump, ops, sending unit. it wont start after its sat for a while , once we get it started on a shot of either it runs awesome no complaints, shut it off turn it back on easy!, but if it sits over night it will not start in the morning, not sure why this problem persists . any body else know? he did get used glow plugs, new ones be here tomorrow !

Bad glow plugs are the root of cold starting problems,switch to Bosch Duratherms for best results.
Also be sure to test every glow plug lead for power to the plugs when the relay cycles,there are fusible links on every lead that can burn out and links for each side.

alright i will check tomorrow and let you know how we made out, thanks!

These engines become addicted to ether too. So use an aerosol lunricant like WD-40 instead.