6.9 no start below 60 degrees or so

[Mad Maxine]

She starts immediately when warm and cold (when the ambient temp isn't cold). All you need is to bump the key and she's off and running. However, we have had a cold snap here in Texas (40 degrees) and now she won't start. Has a pushbutton glow plug circuit (everything is getting 12v on/off at solenoid), all new Motorcraft glow plugs and new glow plug wiring harness. She wouldn't start at all before I put in the new plugs. Now it seems like the glow plugs will do the job, but only when it's not too cold.
Truck is relatively new to me, still figuring out her quirks.
Any ideas on where to start troubleshooting would be appreciated.
Thanks!

 

[ihc1470]

Plug the block heater in for a couple of hours and see what it does, that is if the block heater works.

 

[Indadesert]

Plug the block heater in for a couple of hours and see what it does, that is if the block heater works.

Got to say what would that have to do with a no start at 40deg.

The issue is either the plugs are not working properly or the fuel delivery is not right or the advance is not working or it’s cranking to slowly (batteries)

 

[rreegg]

Got to say what would that have to do with a no start at 40deg
The issue is either the plugs are not working properly

Yes. Running the block heater in this instance is to validate/narrow down an issue with the glow plug (GP) system. If still no start with a functional block heater the issue is likely not GP related.
This is standard trouble shooting protocol for no-start-when-cold conditions as, in theory, it is a low hanging diagnostic fruit.

 

[ihc1470]

Always start with the easy cheep things. A working block heater will tell a very good story and help led you down the correct path.

 

[Mad Maxine]

I guess here’s a real newbie question: when starting cold—once to the floor and let off, pedal on the floor til she starts, or no pedal at all?

 

[Mad Maxine]

I’ll see if it works (block heater)

 

[DaveBen]

NO PEDAL at all. The injectors will give the engine enough fuel to start. I have owned a 7.3 IDI , a 6.0 and an old 8V92TA (Detroit Diesel). None of these needed fuel to start.

 

[IDIBRONCO]

NO PEDAL at all. The injectors will give the engine enough fuel to start. I have owned a 7.3 IDI , a 6.0 and an old 8V92TA (Detroit Diesel). None of these needed fuel to start.

Wrong on the IDIs. Here's Ford's recommendations from my sun visor sticker. See #2. Not that they won't start without the pedal depressed, it's just what's recommended by Ford for easier starting.

 

[franklin2]

Wrong on the IDIs. Here's Ford's recommendations from my sun visor sticker. See #2. Not that they won't start without the pedal depressed, it's just what's recommended by Ford for easier starting.

Along with adding some fuel, it lets the fast idle solenoid extend. It's strong enough to hold the throttle open, but not strong enough to open it by itself.

I have to ask the original thread starter; How long are you holding the glowplug button down? Or are you just pushing it and releasing it. Sounds like you are new to diesels is why I ask.

 

[ihc1470]

NO PEDAL at all. The injectors will give the engine enough fuel to start. I have owned a 7.3 IDI , a 6.0 and an old 8V92TA (Detroit Diesel). None of these needed fuel to start.

From the owners manual for 1994

 

[ihc1470]

I guess here’s a real newbie question: when starting cold—once to the floor and let off, pedal on the floor til she starts, or no pedal at all?

Depends on temp. Either half if above 32 or to the floor below and hold. I usually go to the floor as it will not hurt anything. Just let up when it starts. Pumping does nothing on a diesel.