Is it normal for my -92 econoline 7.3 idi to have weaker interiorlight when glowing? Btteries are tested ok and fully charged. My voltmeter also drops on afterglowing when its running. I also have to glow it two times now and then to get it started in the morning. is this normal or worn glowplugs?

 

Normal for dim light.............If you observe the volt meter it will drop to about 8 volts while GPs are warming, when the cycling starts the voltmeter will swing back and forth until cycling quits even after the start.

If you have a CDN vehicle with DTRLs then you should put the Pbrake on to kill the lights while starting.

Do you attempt the start as soon as the cycling starts, how long does the WTS light stay on. Should be 10-12 seconds in cold weather anything much shorter would indicate some GPs may be burned out.

 

I don't have DTRL, and the WTS lamp are on about 11 seconds. It fired right up after 11 seconds glowing and 5 -10 seconds cranking. I will assume this is normal for an IDI in wet cold weater (4.3 degree celcius and rain). This is not yet my daily driver so I haven't used it for at least three months, but I start it up once in a while

Another question, blue'ish smoke on startup and no smoke while hot in accleration or other load conditions Are there some adjustments I should make? The odo-meter says ca 104K miles.

 

Blueish smoke is normal on cold starts, but the 5-10 seconds of cranking is long.... possibly some air is getting into the system over extended sitting times.

Next time you go to start it after sitting have someone crank it over and you press the Schrader valve to see if much air comes out...use a rag to catch fuel.

Also try double cycling the GPs, turn to run, watch the WTS light when it goes off turn of power, then turn on again do WTS and this time start it right when the light goes out.
Not sure if you saw this info.........

GLOW PLUG CONTROL
HOW THE CIRCUIT WORKS
The Glow Plug Control circuit applies power to the Glow Plugs, which heat the combustion chambers so that the diesel engine can be started.
Glow Plug Controller
The solid-state Glow Plug Controller, attached to the top of the engine block, controls the Glow Plug pre-glow and after-glow time. It also controls the circuit’s operation by sensing engine temperature, Glow Plug voltage and after-glow voltage
from the start/run circuit.
When the Ignition Switch is turned to START or RUN, voltage from Maxi-fuse K is applied through the Glow Plug Controller to the Wait-To-Start Indicator Lamp.
The Glow Plugs heat up in zero to fifteen seconds, depending on engine coolant temperature. After the Glow Plugs heat up, the controller cycling switch opens and turns the Wait-To-Start Indicator Lamp off. The Glow Plugs are now warm enough for the engine to be started.
At the same time the Ignition Switch is turned to RUN, voltage from Maxi-fuse K is applied to the after-glow timer (located inside the Glow Plug Controller). The after-glow timer cycles the Glow Plugs for up to two minutes, depending on engine temperature. The after-glow timer then opens. The Wait-To-Start Indicator Lamp will not light during the after-glow period.
If the Ignition Switch is turned OFF, it can be turned to ON immediately, and the Glow Plug heating cycle will start again.
Diesel Start/Run
The diesel engine uses two batteries to provide extra power for starting and Glow Plug heating. Power is applied from the batteries, through heavy gauge wires, to the Starter Solenoid (located in the Starter Motor assembly). When the Wait-To-Start Indicator goes out, the Ignition Switch can be turned to START.
With the Ignition Switch in START or RUN, voltage is supplied to the Fuel Heater, Fuel Shutoff Solenoid, and the Engine Temperature Switch through Maxi-fuses K and U.
The Fuel Heater is in the Fuel Filter/Separator. It heats the diesel fuel, melting any wax that might clog the filter. The heater has an internal thermostat to turn it on as needed.
The Fuel Shutoff Solenoid controls the flow of fuel into the injection pump. With the Ignition
Switch in START or RUN, the Solenoid is energized, and fuel is allowed to flow into the injection pump. When the Ignition Switch is turned off, the solenoid is deenergized, fuel flow stops, and the engine stops running.
The Engine Temperature Switch provides voltage to the Cold Timing Advance Solenoid and the Cold Idle Solenoid. When the engine temperature is below 112°F (44°C), the Engine Temperature Switch is closed. When the Ignition Switch is turned to START or RUN, the solenoids are energized, advancing injection pump timing and engine idle, allowing the engine to run more smoothly when cold. When the engine temperature reaches 112°F (44°C), the Engine Temperature Switch opens. This deenergizes the solenoids, returning the timing and idle to normal.

 

Thanks for taking the time to write that. It was very informative.