1999 struggle to start

[mtmckiddy]

I have a 1999 F250 7.3 powerstroke with 160,000 miles. I have replaced glow plugs and checked power to them. Below 20 degrees F it struggles to start if not plugged in. Sometimes have to try several times. Hypertech code reader does not show any bad sencors. What could it be?

[superduty4x4]

Could be the GPR. How long do you wait to crank- at least until the light goes out I hope? Below 20 you may want to wait a little longer to give the cyls more time to pre-heat, the GP's stay on for about 90 seconds (much longer than the light).
BTW, welcome to the org.

[ktfjammer]

I also had problems. Change my glowplugs with motorcraft glowplugs found brand new on ebay. Change the Glowplug relay, found on ebay also. Now it starts right up even when it was zero degrees outside one day. Used to have to plug in everday every winter. Now never. Try the glow plug relay

99 Ford PSD F350 7.3L
AFE stage II cold air intake
MBRP 4" turbo back exhaust with 4" down tube and
"5" SS tip

[99SMOKR]

u could try cycling the gp's a couple times.... seems to help