7.3 IDI WON'T START
#16
Oh bummer. Yeah,no man,take that advice asap. You really want the 3G upgrade so you can rid yourself of these issues and have a much more reliable ride for pennies on the dollar. All you need is a salvage yard $35 alternator and this will be better than any brand new early alt money could buy. The swap is pretty easy on these trucks too. If I had a early '92 (pre-3g) IDI truck,I would do the swap before putting the truck on the road.
Search in the idi section and you'll find some good write ups too.Don't make it "someday." This is something you want to make today.
Search in the idi section and you'll find some good write ups too.Don't make it "someday." This is something you want to make today.
#17
Oh bummer. Yeah,no man,take that advice asap. You really want the 3G upgrade so you can rid yourself of these issues and have a much more reliable ride for pennies on the dollar. All you need is a salvage yard $35 alternator and this will be better than any brand new early alt money could buy. The swap is pretty easy on these trucks too. If I had a early '92 (pre-3g) IDI truck,I would do the swap before putting the truck on the road.
https://www.youtube.com/watch?v=eeolsEvzqz4
Search in the idi section and you'll find some good write ups too.Don't make it "someday." This is something you want to make today.
https://www.youtube.com/watch?v=eeolsEvzqz4
Search in the idi section and you'll find some good write ups too.Don't make it "someday." This is something you want to make today.
#18
Junior User
Join Date: Nov 2011
Posts: 51

I hope I'm not hijacking this thread, but 7.3 won't start came up during my search. I've owned my 1991 F350 with 7.3 idi for 15 + years. I solved the air intrusion issue many years ago with an electric pump which is installed to bypass the mechanical pump and is on a toggle switch. I use it to "prime" my truck after it's been sitting for a few days or few weeks. I don't think my issue is fuel related.
I replaced the glow plugs (Bosch), glow plug controller, and solenoid quite a few years ago. The down and dirty continuity indicated the glow plugs are all still good. When I turn on the switch on, the WAIT TO START light comes on for 2-3 seconds, then goes off. The voltmeter needle continues to bounce in rhythm of the solenoid clicking and doesn't stop until the truck starts. I usually count to 20 to give the glow plugs ample time to heat up. It was 19 degrees in NW GA this morning, and the truck was especially hard to start. I only crank it over for max 10 seconds at a time because I despise replacing starters. I had to do that 4 times before it coughed up a barn full of smoke and started running smoothly.
Glow plug controller bad? Glow plug solenoid bad? Both? Neither?
I replaced the glow plugs (Bosch), glow plug controller, and solenoid quite a few years ago. The down and dirty continuity indicated the glow plugs are all still good. When I turn on the switch on, the WAIT TO START light comes on for 2-3 seconds, then goes off. The voltmeter needle continues to bounce in rhythm of the solenoid clicking and doesn't stop until the truck starts. I usually count to 20 to give the glow plugs ample time to heat up. It was 19 degrees in NW GA this morning, and the truck was especially hard to start. I only crank it over for max 10 seconds at a time because I despise replacing starters. I had to do that 4 times before it coughed up a barn full of smoke and started running smoothly.
Glow plug controller bad? Glow plug solenoid bad? Both? Neither?
#19
put in a set of MOTORCRAFT ZD-9 glow plugs and all will be good. the 2-3 second WTS light means that least 3-4 glow plugs are bad. the clicking means the glow plug controller is still good.
waiting 20 seconds does no good, when the wait to start light goes out, the controller stops powering the glow plugs except for a brief second when it "clicks".
aftermarket glow plugs do not work with our engines, or burn out a lot faster than motorcrafts. my 88 has 495,000 miles on it and is only on it's 3rd set of glow plugs.
waiting 20 seconds does no good, when the wait to start light goes out, the controller stops powering the glow plugs except for a brief second when it "clicks".
aftermarket glow plugs do not work with our engines, or burn out a lot faster than motorcrafts. my 88 has 495,000 miles on it and is only on it's 3rd set of glow plugs.
#20
Junior User
Join Date: Nov 2011
Posts: 51

Thanks. I ordered a new set of Motorcraft plugs this morning.
#21
by the way, you can still use the truck with bad glow plugs.
plug it in 2 -3 hours before going out and it will crack rite off.
or disable the glow plugs and give it a 1 second spritz of starting fluid into the air intake.
you are doing the proper thing with limited crank time to prevent overheating and burning out the starter too.
20 seconds crank time, 2 minutes cool off time.
plug it in 2 -3 hours before going out and it will crack rite off.
or disable the glow plugs and give it a 1 second spritz of starting fluid into the air intake.
you are doing the proper thing with limited crank time to prevent overheating and burning out the starter too.
20 seconds crank time, 2 minutes cool off time.
#23
if the heater is still good, just replace the cord for $22.50:
https://www.ebay.com/itm/Ford-7-3-6-...!-1:rk:22:pf:0
or heater and cord, for $57:
https://www.ebay.com/itm/Ford-6-9-7-...4383.l4275.c10
https://www.ebay.com/itm/Ford-7-3-6-...!-1:rk:22:pf:0
or heater and cord, for $57:
https://www.ebay.com/itm/Ford-6-9-7-...4383.l4275.c10
#25
Junior User
Join Date: Nov 2011
Posts: 51

Ok, so installing new ZD-9 glow plugs was not the fix. Now, when I turn on the switch, the wait to start light comes on, then the clicking starts, BUT the voltmeter needle doesn't bounce back and forth like it did before. Any help appeexiated.
#29
Junior User
Join Date: Nov 2011
Posts: 51

Well, I seem to be digging a deeper hole for myself. After a total of 14 hours under the hood and under the dash, I now have a larger problem. This may or may not be related to the glow plug issues I still haven't solved. If I need to be on another thread, don't hesitate to redirect me - I don't get offended by constructive criticism.
When I turn on the switch.....NOTHIING HAPPENS!!! No voltmeter activation, the fuel gauge doesn't move, my auxiliary fuel pump (the one I use to beat the air intrusion issue from years ago) doesn't work. Lights, horn, interior lights and electric hydraulic dump all work as intended, but none of the switched circuits work.
A decent wiring diagram would be a great help. Also, if you've ever had a bad switch actuator arm (broken, etc) or a faulty ignition switch (the one that bolts to the steering column, let me know if this no NOTHING could be a result of those two things. I really like this old '91. It isn't pretty - as a matter of fact, it's almost past ugly - or used daily, but when I do, it's usually overloaded, pulling a skid steer, tractor and equipment, or firewood/mulch/gravel/dirt.
Thanks in advance
When I turn on the switch.....NOTHIING HAPPENS!!! No voltmeter activation, the fuel gauge doesn't move, my auxiliary fuel pump (the one I use to beat the air intrusion issue from years ago) doesn't work. Lights, horn, interior lights and electric hydraulic dump all work as intended, but none of the switched circuits work.
A decent wiring diagram would be a great help. Also, if you've ever had a bad switch actuator arm (broken, etc) or a faulty ignition switch (the one that bolts to the steering column, let me know if this no NOTHING could be a result of those two things. I really like this old '91. It isn't pretty - as a matter of fact, it's almost past ugly - or used daily, but when I do, it's usually overloaded, pulling a skid steer, tractor and equipment, or firewood/mulch/gravel/dirt.
Thanks in advance