I have a 89 f250 whit a 7.3 not turbo, i change glow plug, i change the glow plug relay, batteries are good and when i make the glow plug plug cycle, the wait to start light like the cycle is making but look like nothing going on, i need help cause no ford garage and no one around here know a bit on those truck ...
7.3 idi hard start
- Thread starter Laurent
- Start date
SebastIDIan
Full Access Member
Can you hear any clicking while the wait to start light is on? How long does the light stay lit for? How fast does it crank?
Conky
Registered User
2 glow cycles an hit it with the Cosby
Jump the two large studs on the relay for 10 seconds and see if it starts then. If it does your glow plugs aren’t firing. If it doesn’t then it’s either a fuel issue or you don’t have enough glow plugs working.
DrCharles
Full Access Member
You can tell from the dash voltmeter if the glow plugs are drawing current... should be down near the bottom (8-9 volts). Also, I know "cold" in Ontario in Dec. can be really cold and 10 sec. glow is not enough.
Are you sure all eight glow plugs are connected and functional? A bad plug may still show resistance but it needs to be really low (tenths of an ohm) to get red hot.
Are you sure all eight glow plugs are connected and functional? A bad plug may still show resistance but it needs to be really low (tenths of an ohm) to get red hot.
That short ten sec. cycle is too short and usually indicates that one or more of the glow plugs are not heating. The first try on a cold engine the glow plugs should remain energized for at least 30 seconds. You can watch the voltage drop while the glow plugs are heating.
Your relay might not be wired right if you recently replaced it. What kind of glow plugs did you use?
DrCharles
Full Access Member
OK. Your glow plugs are not working then. Either a bad connection (there is a plastic connector that is known to fail over time) or the controller is not actually turning on the plugs even though the light says it is.
Wes already suggested a test to help narrow that down... you will also see a good sized spark when you jump the relay terminals if the wiring/plugs are ok.
Wes already suggested a test to help narrow that down... you will also see a good sized spark when you jump the relay terminals if the wiring/plugs are ok.
I use the ford zd9 one for the relay its wired the sane thing that it was! I took picture tu make sure every thing was at the right place! And perfect i will order new controller and make sure every wire and connection is perfect!
Any fuel around the IP connections? My connection from the filter to the IP needs a new olive. I just tightened it out 11 months ago. Recently it began leaking again, letting air in. After tightening it down again, no more hard cold starts.
