Cold Weather, Glow plugs, timers, and Hard starts

[Fordnut74]

This is pretty much an annual event that every year with cold weather. Some start to experiance Hard Starts, excessive smoking when cold, running rough once started, or simply just hard to start. For those of you new to diesels, Most all of them use Glow plugs to help the engine start when cold. Glow plugs are similar in shape to a Spark Plug, and are little heaters that mount in the head and just barely stick into the combustion chamber.

Diesels operate off of compression and heat unlike a gasoline engine that requires spark. Standard Diesel has an autoignition point of 410f. That means the air in the cylinder needs to achieve at least 410 before the engine will start. With a cold engine all the heat can be easily taken out of the air preventing autoignition from ever being achieved. With enough cranking eventually heat will start to build up and it will start. The glow plugs provide a heat source for the diesel to ignite until the cylinder walls build enough heat for the engine to sustain combustion on its own. And vegetable oil has an even higher ignition point that will vary based on type. So even a light mixture of Diesel and VO will affect the ignition temperature of the fuel. Without a properly maintained glow plug system, this can also cause hard start issues. NONE OF THIS WILL DAMAGE THE ENGINE!! Just simply the nature of diesels and cold weather.

I have put together some information on what the Glow plug system does in the following posts as written in the Ford Service Manuals, and will also revisit adjustment procedures for the Vegistroke timer cards. Long story short, to ensure a trouble free Winter, Check your Glow Plug system and purge timers. I have countless times troubleshot a hard starting truck to a bad Glow Plug System.

[Fordnut74]

99-2003 7.3 Glow Plug Operation.



Glow Plug Relay Control — Federal
The Glow Plug (GP) Relay Control is used to energize the glow plugs for assisting cold engine start-up. Engine Oil Temperature, battery positive voltage (B+), and Barometric Pressure (BARO) are used by the PCM to calculate glow plug on-time and the length of the duty cycle. On-time normally varies between 1 and 120 seconds. With colder oil temperatures and lower barometric pressures, the plugs are on longer. If battery voltage is abnormally high, the duty cycle is shortened to extend plug life. (The glow plug relay will only cycle on and off repeatedly when there is a system high voltage condition greater than 16 volts.)
An open in the glow plug relay circuit will render the glow plugs inoperative. A short circuit will result in a glow plug's always ON condition.










Glow Plug Relay Control — California
The California glow plug system is composed of solid state Glow Plug Control Module (GPCM), glow plugs and the associated wiring harness. The glow plug on-time is controlled by the Powertrain Control Module (PCM) and is a function of oil temperature, barometric pressure and battery voltage. The PCM enables the GPCM which drives the individual glow plugs. Glow plug on-time normally varies between 1 to 120 seconds. In addition to PCM control, the GPCM internally limits the glow plug operation to 180 seconds regardless of PCM commanded on-time. The power to the glow plugs is provided through the GPCM solid state drivers directly from the vehicle battery. The GPCM monitors and detects individual glow plug functionality, and the control and communication links to the PCM. The failures detected by the GPCM are passed to the PCM using a serial communication signal on the diagnostic line.
Note: Wait to start lamp on-time is independent from GPCM on-time.














Glow Plug Indicator
The Glow Plug Indicator (GPL) is located in the instrument cluster and is used to prompt the operator when the engine is ready to be cranked and started. When the light goes out, the vehicle is ready to start. As a bulb check, the light is commanded on at every key cycle even though the glow plug system may not be required. On-time normally varies between 1 and 10 seconds. Wait to Start indication is independent of glow plug relay on-time as the glow plug system can stay on after the indicator goes off.
F-250/550 and Excursion
The indicator is controlled by the instrument cluster, based on electronic information from the PCM. The PCM sends an electronic signal command, via Standard Corporate Protocol (SCP) communications, to the cluster on how long to keep the indicator on. The instrument cluster performs diagnostics for the GPL circuit.




Part number for Glow Plug From International - P/N 1831646C1

[Fordnut74]

1999-2003 7.3 F250-550 Glow Plug Test System Test Procedures- Federal


Periodicity:
Annually. This test should be performed at least annually prior to cold weather conditions. Individual climates will dictate importance of maintained glow plug system.

KC1 CHECK FOR DTC P0380
• Perform KOEO On-Demand Self Test and Retrieve/Clear Continuous DTCs.
Is DTC P0380 present?
Yes No
GO to KC2 .
GO to KC7 .


KC2 DTC P0380
• DTC P0380 is set when the PCM detects a malfunction in the glow plug relay control circuit.
• Possible causes:
 shorted/open power
 open/grounded circuit
 worn or damaged glow plug relay
• Key on, engine off.
• Measure voltage at glow plug relay coil ignition input, and battery ground.
Is the voltage greater than 10.5 V?
Yes No
GO to KC3 .
REPAIR open in relay coil ignition power. If fuse is blown, CHECK for short to ground. RESTORE vehicle. CLEAR DTCs and RETEST.

KC3 RELAY COIL RESISTANCE TEST
• Key off.
• Disconnect the wire going to the glow plug relay coil ignition ground 1086 (VT/OG).
• Measure resistance through relay coil, between terminals 85 and 86.
Is the resistance between 1 ohm and 8 ohms?
Yes No
GO to KC4 .
INSTALL a new glow plug relay. RESTORE vehicle. CLEAR DTCs and RETEST.

KC4 CHECK SHORT TO POWER
• Install breakout box; leave PCM and wire 1086 (PK/OG) disconnected.
• Key on, engine off.
• Measure voltage between PCM test pin 101 and battery ground.
• Key off.
Is the voltage greater than 10.5 V?
Yes No
REPAIR short to power in circuit 1086 (PK/OG). RESTORE vehicle. CLEAR DTCs and RETEST. GO to KC5 .


KC5 CHECK SHORT TO GROUND
• Measure resistance between PCM test pin 101 and battery ground.
Is the resistance greater than 10,000 ohms?
Yes No
GO to KC6 .
REPAIR short to ground in circuit 1086. RESTORE vehicle. CLEAR DTCs and RETEST.

KC6 CHECK CIRCUIT FOR OPEN
• Measure resistance between PCM test pin 101 and circuit 1086 (VT/OG) eyelet going to the glow plug relay.
Is the resistance less than 5 ohms?
Yes No
INSTALL a new PCM. RESTORE vehicle. CLEAR DTCs and RETEST. REPAIR open in circuit 1086 (VT/OG). RESTORE vehicle. CLEAR DTCs and RETEST.

KC7 CHECK GLOW PLUG RELAY
Note: The glow plug ON time is dependent on oil temperature and altitude. The glow plugs come on between 1 to 120 seconds depending on oil temperature and do not come on at all if EOT is above 55°C (131°F) for F-Series or 30°C (86°F) for E-Series. Verify glow plug control ON time using PID GPCTM.
• EOT temperature below 55°C (131°F) for F-Series or 30°C (86°F) for E-Series.
• Key on, engine off.
• Measure voltage between glow plug feed terminal on glow plug relay and battery ground.
Is voltage present for the time indicated on GPCTM PID?
Yes No
GO to KC8 .
INSTALL a new glow plug relay. RESTORE vehicle. CLEAR DTCs and RETEST.

KC8 CHECK FOR INTERMITTENT CIRCUIT FAULT
• Clear continuous DTCs.
• Grasp vehicle harness; wiggle and shake.
• Retrieve continuous DTCs.
Is DTC P0380 present?
Yes No
REPAIR intermittent circuit fault in glow plug relay circuitry. RESTORE vehicle. CLEAR DTCs and RETEST. Unable to duplicate or identify failure at this time. RESTORE vehicle. CLEAR DTCs and RETEST.

KC9 CHECK GLOW PLUGS
Note: Run these checks if starting difficulty occurs in cold temperatures.
• Disconnect glow plug/injector connectors at both valve cover gaskets.
• Check resistance between ground and each glow plug connector using a digital multimeter and Glow Plug Adapter 134-00132 or equivalent.
Is the resistance between 0.1 and 2.0 ohms?
Yes No
GO to KC10 .
REMOVE valve cover and INSPECT harness for opens and shorts. If harness is OK, INSTALL a new glow plug.

KC10 CHECK GLOW PLUG CONNECTORS
• Check resistance between each glow plug contact in the engine harness and the two brown wires on the glow plug relay.
Is the resistance between 0 and 2.0 ohms?
Yes No
INSPECT inside of air filter-to-turbocharger air duct. If dirt or abrasives are present engine may be worn. REFER to the Workshop Manual for engine testing and repair procedures. INSTALL a new engine wiring harness.

Procedures and information from the Ford Powertrain Control/Emissions Diagnosis Manual.

[Marv]

Great info Jason, thanks!!

Also reminds me that I need to adjust my timer cards on the V3. I never did adjust the run time card.

[Fordnut74]

So once the glow plug system is working correctly, now we need to adjust the timer cards for the system. In our system we use two timer cards- one for the Engine run and one for the Purge (engine flush). When the system is off, or not up to temperature yet, nothing happens. When in the "Auto" mode as soon as you turn the key on, the electric heater jacket will begin to heat up (if installed). As the engine warms up hot coolant is circulated first to the V3, then to the tank. 12vdc switched power is supplied to the temp switch through the system switch. When the V3 exceeds 140f, the temp switch will then send pwr to the trigger on the Timer cards and the WVO pump relay. This of course activates the timer cards -not to be confused with the power for the timer cards. Now with the pump on, once the system exceeds 55psi the pressure switch will activate and reroute power from the Diesel pump to the indicator light on the dash. This is the normal mode of operation. Should the pressure on the Vegistroke drop below 50, the pressure switch will default back to the "at rest" position, and return power from the indicator light to the diesel pump restoring the OEM fuel system pressure. When this happens, the WVO system does not shut off- The timer cards stay on, and the Vegistroke pump stays on attempting to build pressure. Only after the key is shut off or the system switch is turned to off will the system be shut off.

So with the system operating normally, if you turn the key off, this removes the 12vdc sw from the trigger on the timer cards initiating their countdown, and also shuts off the relay for the WVO pump and heater jacket. Since the WVO pump is off, pressure drops and the control of the diesel pump is returned to the OEM computer. At the same time the purge timer card is sending a signal to the 2 port solenoid on the manifold allowing the outlet of the V3 to bypass everything in the manifold. Now the WVO supply line becomes a return line feeding back to the AUX tank. There is a specific orifice in the manifold to restrict the flow making sure that fuel pressure is not dropped too low during the flush process. This process lasts about 10 seconds, or roughly 10oz then the purge solenoid closes. Now the engine continues to run for the an additional 40-50 seconds after the purge solenoid closes.

To adjust the timer cards: Refer to page 18 of our installation manual for a picture of the control module and a description of the components. Have a Stopwatch available.

1) Turn the KOEO(Key On Engine Off). The truck does not need to be running or warmed up for this test.

2) Turn system to manual on. This will be the green light side. This forces the timer cards to become active. You should notice a red light on each card.

3) Adjusting the Purge card.(bottom) Turn the system back to OFF(middle position), leaving the key on and start the stopwatch. Watch the light on the bottom card, this will be the purge card. The LED should extinguish after 9-10 seconds. If not adjust white thumbwheel and retest. CW will increase the time and CCW will decrease the time.

4) Adjusting the Engine Run card(top). Turn the system back to manual on, KOEO. Ensure that the led is lit on the top card. Turn the system to off and start the stopwatch. The light should extinguish in 50-60 seconds. If less than 50 seconds set the thumbwheel to the max clockwise position and try again. If still less than 50 seconds contact DFA for support.


Completing the Glow plug system testing and making sure your Vegistroke is timed correctly will be great insurance in protecting yourself from the cold weather and hard starts!

[Marv]

Jason I think you just answered about 50 questions that have been posted about system operation in that last post!! Lol...

Again, thanks for the good info!

[Jack_Toepfer]

I feel much more comfortable playing with the timer cards if need be now.

[GRNBLDR]

What effect will improper purging cause in cold starts. My truck has had very hard cold starts. Long winding. When I ran on pure diesel after a few days the starts were crisp. Change fuel filters? Thoughts?

[lancaster,pa]

What effect will improper purging cause in cold starts. My truck has had very hard cold starts. Long winding. When I ran on pure diesel after a few days the starts were crisp. Change fuel filters? Thoughts?

I have again readjusted my purge and run times as the weather got colder. Setting purge to 11 seconds and run time to almost 2 minutes has corrected the problem for me. I don't have an explanation as to why my truck requires these settings which are longer than DFA recommends. I have however, experienced the same smooth starts that you have if I ran my vehicle the day before on diesel only. Comparisons I have made between the quality of starts with running diesel the day before vs. running veg and going through the auto shutdown with the recommended purge and run times have been completed with consistent circumstances (vehicle shut down in 45F temps, sitting overnight outside for 12 hours, and starting the next day with 30F ambient temps). - Patrick

[Jack_Toepfer]

Patrick, I'm still running standard DFA settings and my truck starts with a snarl in 20* temps. Are you using your block heater?

[lancaster,pa]

Patrick, I'm still running standard DFA settings and my truck starts with a snarl in 20* temps. Are you using your block heater?

Jack,
Thanks for the reply. I would really like to get my system in line with what everyone else is doing. Your suggestions will be appreciated.

I know use of the block heater results in smooth starts after auto shutdown using the standard DFA settings. However, I also know use of the block heater was masking the symptoms of the problem I am experiencing. At 30F, my vehicle starts smoothly without the use of the block heater if I had been running it only on diesel the day before. At 30F I experience hard starts without the use of the block heater if I had been running veg the day before and auto shutdown using the standard DFA settings. If I purge 11 seconds and run for 2 minutes, the vehicle will start and run smoothly at 30F without the use of the block heater.

The V3 was designed to purge/run all the veg out of the system after the auto shutdown sequence is complete. For some reason, my system is not doing that with the standard settings. After determining what settings are actually getting all the veg out of the engine, I have begun using the block heater again but still want to correct my problem. Help! - Patrick

[Jack_Toepfer]

I see Patrick. I don't bother not using it anymore... so I wouldn't know.

[powerstroke73L]

This is third winter with the 7.3L but the first on veggie. So far the lowest temp I've seen this year is 15 degrees last Friday night into Saturday morning. I run 15W-40 year round so I get "the romps" when its gets REALLY (below zero) cold-it romped twice and evened out when I cranked it up yesterday morning. That was the first time I'd really heard the starter dragging at all this year, but I still wouldn't call it a "hard start." The Optimas really seem to help too. Switching to 5W-30 is supposed to cure the romps entirely in 7.3Ls but all I can find near me is Rotella 5W-30 full synthetic at $22.00 a gallon!

[Marv]

Jack,
Thanks for the reply. I would really like to get my system in line with what everyone else is doing. Your suggestions will be appreciated.

I know use of the block heater results in smooth starts after auto shutdown using the standard DFA settings. However, I also know use of the block heater was masking the symptoms of the problem I am experiencing. At 30F, my vehicle starts smoothly without the use of the block heater if I had been running it only on diesel the day before. At 30F I experience hard starts without the use of the block heater if I had been running veg the day before and auto shutdown using the standard DFA settings. If I purge 11 seconds and run for 2 minutes, the vehicle will start and run smoothly at 30F without the use of the block heater.

The V3 was designed to purge/run all the veg out of the system after the auto shutdown sequence is complete. For some reason, my system is not doing that with the standard settings. After determining what settings are actually getting all the veg out of the engine, I have begun using the block heater again but still want to correct my problem. Help! - Patrick

Patrick, are you saying the 2 min setting is working for you, or are you still having to use the block heater if you've ran vegi the day before?

I think I might have gotten myself confused...haha.

[lancaster,pa]

Patrick, are you saying the 2 min setting is working for you, or are you still having to use the block heater if you've ran vegi the day before?

I think I might have gotten myself confused...haha.

Marv,
I like to use the block heater as the temp gets colder just for the health of the engine. However, I have intentionally not used it several times recently just to test my system. What I found when I didn't use my block heater was that my 7.3 started great the next day if I had been running diesel before shutting down. I also found that I was having rough starts/idling if I had run veg and shut down on auto the day before. If I use the block heater, I get smooth starts either way. I believe the block heater is allowing my vehicle to start and run smoothly even with a little veg in the injectors.

As a result, I have been increasing my run time in an attempt to get all the veg out of my injectors. Since my last post, it has gotten colder and I have had to increase my run time even more. I shut down today with an 11 second purge and a 2minute 25 second run (will try that for a couple days to see how it works).

I realize that I could just always use my block heater, but I don't like the idea of any veg being in the engine at start-up. You seem to be up on all this stuff and any help would be appreciated. - Patrick