Glow Plug Cycle?

[pwjackson]

I have been reading up on manual glow plug switches and I am going to install one so that my factory control will still work in conjunction with my push button. My question is if I allow the factory system to glow how long should I wait after the Wait to start light goes off before giving my plugs another shot from the manual button? Should I wait 10 seconds and then glow them for another 5 ?

 

['94IDITurbo7.3]

If the factory system is working and you have 8 good plugs then they should not need a second round of heat.

How long does your WTS light stay on for?

 

[vegas39]

Yeah, gotta be careful or you will burn them out fast. I had a manual switch in mine and as careful as I was, I managed to burn mine out.
I have the old style controller that everyone seems to hate and when it quit, I went ahead and replaced it while my heads were off and so far almost two years later, all my plugs are still good.

 

[Compu Doc]

I have been reading up on manual glow plug switches and I am going to install one so that my factory control will still work in conjunction with my push button. My question is if I allow the factory system to glow how long should I wait after the Wait to start light goes off before giving my plugs another shot from the manual button? Should I wait 10 seconds and then glow them for another 5 ?

Why fix it if it is not broken?

 

[franklin2]

Keep the automatic system and use it, or disconnect it and use the manual system. There is no purpose in trying to use both at the same time.

And the manual system is not rocket science. It has been used for years(and still is) on tractors and heavy equipment. It requires you knowing how your engine reacts to the outside temperature, and how long to hold the button. That comes from experimentation and using the manual system in the wintertime.

I think part of the problem is people expect these diesels to start like a gas engine. There is nothing wrong with cycling the glowplugs a little bit, cranking a little bit, and then doing it all over again and even a 3rd time before it will start. I have never understood why people want to hold the glowplugs on for 10 seconds or more at one time. I suppose they want it to crank right up on the first try, or they are trying to simulate the factory controller, but that method is what puts the glowplugs in danger. We all know one of the factory's main goals was to make a diesel more like a gas engine and try to beat the bad rap diesels have always had with the public.

 

[lotzagoodstuff]

I like the factory system as it "tells you" if you burn out a glow plug as it will shorten the cycle.

Just my .02.

 

[Kevin 007]

I have a full manual setup. I bypassed the factory controller and installed a HD high amperage solenoid and that fires my glow plugs. And a little puch button to activate the solenoid. I have done this on MANY older diesels as soon as they start to show signs of controller failure.
I currently have 3 running with this setup.

My idi's always ran about 12 seconds on factory glow system on cold days. So what I do with the manual switch is cylce for 10 seconds, off for 4 or 5 secons and cycle for another 5. They start great every time and im not worried about burning up pulgs holding them to the 12-13 second mark every day like the controller did.

 

[BigRigTech]

Mine are manual, haven't changed a GP in over 1.5yrs...I check them when I change the oil or grease the truck....Starts with much less burn time than the controller would have allowed.

 

[pwjackson]

Well I have the old controller system and I installed new motorcraft plugs last year and I have a new relay installed. When it get so to be about 50 degrees and the plugs cycle for what seems to me the normal time of 12 to 15 seconds my truck does not seem to want to start. cranks and sputters and then cranks and sputters until it fires. I am going to test my plugs before I do anything. I am also going to check batteries, maybe it just isn't cranking fast enough. Starts great when its warm out though. I guess my thoughts were that the controller is heating the plugs up properly?

 

[Compu Doc]

You could have other issues than glow plugs. It's not a bad idea to check them though but if they are glowing for the normal time I would look to fuel system related issues. You could also try putting your foot on the go pedal about half way while cranking in colder weather if your not doing that already.

 

[bbjordan]

If you haven't done the wiring bypass mod from the start relay to the glow plug relay, you should do it. It bypasses the wiring connector which is a know problem. Also check and make sure you have good connections to the glow plug relay, especially the ground connection. Corrosion takes its toll on an antique truck.

Compu_Doc, if you have to put the pedal half way, it could indicate a few of things:

1) the cold start (high idle is not set high enough)

2) the injectors may be weak/leaking
If they leak , at low cranking speed they may not give a good spray pattern when they pop. If they are weak, they will open early effectively advancing the timing.
Pop test to check.

3) the injector pump is weak
Expensive to check. There will be other symptoms if that is the case.

4) the timing may be too far advanced
Pressing the pedal half way will introduce more fuel (see #2), but it also significantly retards the timing.

Never the less, good advice Doc.

 

[franklin2]

Compu_Doc, if you have to put the pedal half way, it could indicate a few of things:

1) the cold start (high idle is not set high enough)

2) the injectors may be weak/leaking
If they leak , at low cranking speed they may not give a good spray pattern when they pop. If they are weak, they will open early effectively advancing the timing.
Pop test to check.

3) the injector pump is weak
Expensive to check. There will be other symptoms if that is the case.

4) the timing may be too far advanced
Pressing the pedal half way will introduce more fuel (see #2), but it also significantly retards the timing.

Never the less, good advice Doc.

Fold down your sunvisor and read the "diesel engine starting procedure". For temps above 32F hold the throttle halfway open. For temps below 32F hold the throttle fully open.

 

['94IDITurbo7.3]

Fold down your sunvisor and read the "diesel engine starting procedure". For temps above 32F hold the throttle halfway open. For temps below 32F hold the throttle fully open.

Exactly. thats what the diesel booklet that came with the truck said as well.

 

[damac]

I brought my first truck home about 2 years ago. First thing I did was read about a manual controller because I saw what happens when bad owners and faulty parts go bad Puff puff went the autolite plugs.

Installed the manual button and motocraft plugs and here were are with everything still working great.

Doesn't matter if its summer or down into the teens in winter. I hold the button for 8-10 seconds then hit the starter and it starts within a handfull of revolutions.

You do have to learn your truck and get used to how diesel works. If your cables, battery, starter are hurting this can effect so much and might just trick you into thinking your glowplugs are bad and you start cycling them too much.

Another big one is air intrusion. My first glowplug cycle was wasted at the first start of each day in the months after I got my truck. I did the return line replacement but fuel was draining back to the tank somewhere even though I didn't have fuel leak puddles on the ground.

I moved to an electrical carrier pump and it turned the truck into a completely different vehicle. Key on, let it sit 10 seconds to prime fuel, then hit glowplugs and immediately start and those chugging misses went away

Also in summertime I have parked the truck in the shade and gone somewhere for a few hours and I can come back to the truck and hit the starter with NO glowplugs and the truck starts instantly. In winter I don't even bother and hit the plugs.

 

[Goofyexponent]

Exactly. thats what the diesel booklet that came with the truck said as well.

This is because at idle, these trucks don't introduce much fuel into the cylinder....REALLY efficient idlers.

All you are doing at a WOT cold start is putting a LOT more fuel onto the HOT GP.....this will help light the fire.

Think of it as trying to light a camp fire with a drop of gasoline, vs a liter of gasoline.....the liter is going to singe eyebrows....but it will get the fire going!