[Fassy]

Hei Guys
I know this cold start issue is going on for ever on theses 7.3 IDI Diesel.
1990 F-250 Super Duty 7.3 IDI (Non turbo)

1. Changed out all injectors (was necessary anyway)
2. New Glow plugs
3. New return lines, with O-rings and caps.
4. New electrical feeding pump (pre owner already changed to electric version)
5. Diesel filter new
6. Cold start solenoid is working.
7. New batteries (was needed anyway)
8. New Starter, including all cables

But when its cold (-1 to - 10 degC) here in Norway
It is freaking hard to start, on the end i get it to start with cuffing and smoking.

I am out of ideas now.

Greetings Torsten

 

[oldrebuiltdodge]

Some chuffing and smoking is normal. Diesel engines don't like cold weather, and complain when made to run while cold. How long does the wait to start light stay on? Is there power getting to the glow plug relay? Have you checked voltage to the glow plugs? Wait to start light should stay on somewhere around 20 seconds depending on how cold it is. It works through resistance built up by the heating glow plugs. When it shuts off initially, it will cycle for a while longer until everything warms up. If all of that is working as described, don't worry about further checks If not there is a fusible link coming off of the relay on the fender well. It can show to have voltage at the glow plug relay until there is a load on it, then it will loose everything. That fusible link is no good if that happens. Power across the relay should be battery voltage under load, if not, the relay is weak. There is a resistor right off of the relay, just past it there should be about 10 volts, and 10 volts at the glow plugs. From there the fuel system needs to be in good shape as well. After that you need to start thinking about how the engine compression is doing.

 

[Fassy]

Some chuffing and smoking is normal. Diesel engines don't like cold weather, and complain when made to run while cold. How long does the wait to start light stay on? Is there power getting to the glow plug relay? Have you checked voltage to the glow plugs? Wait to start light should stay on somewhere around 20 seconds depending on how cold it is. It works through resistance built up by the heating glow plugs. When it shuts off initially, it will cycle for a while longer until everything warms up. If all of that is working as described, don't worry about further checks If not there is a fusible link coming off of the relay on the fender well. It can show to have voltage at the glow plug relay until there is a load on it, then it will loose everything. That fusible link is no good if that happens. Power across the relay should be battery voltage under load, if not, the relay is weak. There is a resistor right off of the relay, just past it there should be about 10 volts, and 10 volts at the glow plugs. From there the fuel system needs to be in good shape as well. After that you need to start thinking about how the engine compression is doing.

Thank you for your detailed reply.

1. Checked glow plug draw for all together, around 125A
2. Checked each glow plug cable with a glow plug to minus. Glows good in 10-15 sec.
3. Voltage to each plug around 9,6V
4. I forgot to say last time. When motor heater is connected. The truck start way better. Not on the first try but on second.

I am also worried about the motor now.
Exhaust popping sound he has since I bought it. But sounds like it's getting louder. Sounds like diesel ship.

Best regards Torsten 🇧🇻

 

[oldrebuiltdodge]

From your description, it sounds like you might have one or more exhaust valves burned, which would lower the compression making it hard to start. I have pulled heads without pulling the engine, but it isn't easy.