I thought it was 6-8 sec. and 10 was getting close to fying them?

DT

 

I was holding them on for 10 seconds and whatever was left of them when I bought the truck, was blown away in the 2 weeks I had it. So maybe 10 is bad.. /ubbthreads/images/graemlins/shrug.gif

 

I would go 6 sec. for 50F+ and 2 6 sec. cycles for below that if it needs more.

10 sec. will burn out depending on the type of GP's

Only use the Motorcraft/Beru as the others tend to swell up if burned out and then break and drop into the cylinder once you try to remove them.

DT

 

I'd look into either the dual coil or constant duty plugs. They will not burn out nearly as easily as regular plugs.

 

Do you folks not use a glow plug controller, or are you mostly just manually operating them for about 6 seconds?

 

I use the solid state controller. That way, anyone smart enough to read the big red light that says "WAIT TO START" can drive the truck. My 3 year old little girl even tells me, wait, wait wait, ok, start it! /ubbthreads/images/graemlins/smile.gif

 

That's just adorable! She could probably help a lot of people with these trucks.

 

I have had my GP's on push button for two years and all is still well, I leave mine on for 7 seconds, I will count like this, one thousand one, one thousand two, one thousand three, etc. until I get to seven then turn off the switch. Count a few times watching your second hand on your watch until you learn just how fast to count, with a little practice you can come out right on 7 seconds, I have a toggle switch with a spring return to off when I let up on it, on mine which works just like a push button.

Good luck,

Bill Miller.

 

The amount of time may depend somewhat on where you live and what time of the year it is. The factory controllers will actually energize for up to 13 seconds or so, but whatever number you decide on, I'd recommend using the second hand of a watch, or build my foolproof controller that does the counting for you. You'll find the schematic in my album link below.

 

ive found that the time in which to power your plugs varies greatly with the condition/cca's of your batteries /ubbthreads/images/graemlins/biggrin.gif

 

I bought my truck in August 1985. It has 155000 miles. I have not replaced any of the glow plugs. The truck always starts immediately anytime the temp is above 30 deg. If it is colder sometimes it takes a couple of extra turns to fire off. The controller obviously does a great job of controlling how long the glow plugs are on. In summer the controller cycles very fast. In the winter it will come on a couple of times even after the truck is running. Even a girlie man could start my truck without burning out the plugs. If my controller ever goes out, I am definitely going to replace it with a new one. Yes, I probably need to look at replacing the glow plugs but as long as it is not hard to start I am going to leave them alone. If it aint broke don’t fix it. As one other person stated the condition of the batteries seems to have the most effect on how fast it starts. I had to replace my batteries about a year ago and I was surprised at the difference in the starting.

 

word... haha /ubbthreads/images/graemlins/biggrin.gif sometimes i wonder if people realize just how much juice GP's draw(much more than cranking the motor for a few seconds)...so with weak or old batteries your cycle times will be way out of wack...for example i have some old crudy batts in my truck and my beru's need 8 seconds(one one thousand, two one thousand) even when its only 60 deg at night!

 

[Even a girlie man could start my truck without burning out the plugs. If my controller ever goes out, I am definitely going to replace it with a new one.]


When your controller goes hopefully you'll notice it before it takes out your GP's, which is still not a big deal untill your lose a tip or two into to the combustion chamber and thats when the fun begins. Then the reasoning behind that push button / toggle switch will make more sense.

 

Hmm. It seems a few gusy have been lucky enough to keep the factory system in there for a LONG time inclluding the godfather, Mr. Agne on the Moose....but more commonly this thing will fail in teh on position and may make the glow plugs fry and drop a tip. Usually Motorcrafts or other decent plugs don't do this. To answer the original poster's question...those of us with the manual system are eliminating the GP controller and in effect We become the controller. The way it is from teh factory on the later 83s-86 is that the temp sensor in the driver's side head sends a reading to the purple wire on the relay and tells it how long to keep the plugs on. This system is really great until the relay latches in the on position..then it kills most/all of the plugs and can cause engine damage. Motorcraft and other premium plugs(read NOT Autolite or Crapion) can stand being on 12 seconds or so, but if you have good compression and no air leaks you only need 6-8 seconds to get the truck started. I went with the solid state conversion mainly because I wanted other people to be able to drive my truck and not to have to bite my nails every time she went in for service that somebody would burn my plugs out or worse decide she didn't have glow plugs and needed ether!

 

[ QUOTE ]
may make the glow plugs fry and drop a tip.

[/ QUOTE ]

If the glow plugs are fried, I would think the tips would be gone, so apart from having to replace all your GPs at least the the tips are burnt off..now that's handy! /ubbthreads/images/graemlins/wink.gif

 

[ QUOTE ]
If the glow plugs are fried, I would think the tips would be gone,

[/ QUOTE ]

Not so!! Many of the Cheap glow plugs(Champion and Autolite) will not break off when they fail, but remain in place. What happens is the tips of the glow plugs swell up or bend off to the side, so that it's nearly impossible to get them out of the cylinder. Thus, when you try to remove them, that's when the tips break off, and drop down in there. That's why you should always have the cylinder you're working on at TDC before you try to remove the glow plug. If the tip breaks off, it remains in the pre-chamber and doesn't drop into the cylinder.

Zigg /ubbthreads/images/graemlins/smile.gif

 

More often than not, the tip falls off when the owner tries to remove them. I don't think they fall off on their own, but I wouldn't rule it out. Indeed the battery power IS a primary factor in ON time. This is why the 7.3 controller is superior to all other methods, because it measures the current draw to a known standard and uses that as a basis for on time. Unfortunately, one burned out glow plug, or unexpected wiring resistance throws this whole system out of whack, so it has that weakness. Otherwise, the old style controller, push bottons, and my "foolproof" timer all work on the "about this long should do it" method.