I am just wondering how to make it oem like. I have 6.9 with manual switch for glow plugs.I know my glow plug controler is most likely shot. I would use the 7.3 whole controler. Does it have to be mounted on the engine to sense the heat from the engine or can I place it on the place next to the fender the old relay is mounted? I can not find any tech data about glowplugs here. What is the difference ZD 1 and ZD 9? It is around 20 degrees out and I just have to think how long do I need to hold the switch. I have never played with glow plugs, just put the new ones and that was all. I want to avoid the old style 6.9 but maybe I am just too scared. Like the cavitation,everybody is talking about it,only few have seen it.
Anyway I apreciate any imput guys.

 

The 7.3 style glow plug controller uses the resistance of the glow plugs to sense how long to glow. That being said, I see no reason you couldn't mount it on the fender(the factory turbo models were on the passenger valve cover). I would not go back to the 6.9 style controller. Dads 6.9 years ago stuck in the on position twice and after the second time he switched it to the 7.3 style.

 

When its around 20-40 3-5 seconds does the trick on mine,
I honestly prefer a manual setup, not much to go wrong that you can't figure out in a few seconds, of course there is the danger of over juicing your plugs and burning them up (holding them on for too long) but when its warm and doesn't need em they never cycle like the factory controller does everytime, coolant temp just determines how long.

My setup is the factory solenoid on the fender, a push button flips it and it just has the glow plugs on the other terminal, i plan to pull my old controller and plug the hole.

 

Jan, there are sticky threads at the top of the forum page with a ton of information on both systems. The main difference is the 7.3 system is 6 volts the 6.9 system is 12 volts. The controller on 6.9 threads into a coolant jacket, but the 7.3 controller is solid state and can be mounted anywhere. The factory turbo engine has it on the passenger valve cover so the turbo does not kill it. The Banks kit has a relocation bracket for the 7.3 controller that is part of the up pipe brace. Look in the manual and you will see it. If you decide to use that turbo you already have a place to mount it. The spare engine has the 7.3 controller but I don't remember how it was mounted. Your fear of burning the plugs is mostly true with cheap aftermarket GP's... especially Autolite brand. When they fail the tip swells and won't fit out the hole. If it breaks off you have to pull the head. F### Autolites. Get Beru/Motorcraft.

 

I was just wondering which glowplugs are better, the newer or the older system? Seems the 6 volt would be more effective as the volts and amps drop in freezing temperature. The truck will never be pluged, and we see temps like -25 celsius sometimes.

 

The newer system is definitely better. You have the 7.3 controller on the spare engine, you just need the 6v glow plugs and either modify your wire harness or fabricate a new one with the bullet style connectors. This is definitely a good upgrade especially if you are going without a block heater.

 

You know what is the funny part? Even Ford dealer is unable to order those glow plugs here, unable to order them anywhere except the US car shops, which sell one plug for 20 dollars.

 

Does it glow even the engine is hot? Or the 6.9 does not glow when hot? I just wonder why the sensor in the water jacket has 6 wires comming to it in the old system. If the old system does not glow when hot engine, I would prefer that one, as the truck needs the glow plugs only when cold, once it was run it starts without it just fine.

 

RockAuto sells Motorcraft ZD9's for about $10 each plug. Did you check the spare engine to see what is in it? Spade connector = old style, bullet connector = new style... The brand should be engraved right on the plug. Since that engine was transplanted into a 1992 truck and had the new style controller the harness and plugs should be the new style as well. They might still be good but I would check the brand.

 

Both systems will cycle to start a cold engine, then cycle on and off to reduce emissions until the coolant comes to temperature. They should not cycle (or only briefly) when starting a hot engine.

Edit: I just looked it up, 7.3 controller does not involve any coolant temperature sensor...

Edit 2: according to this thread, the new style module itself senses temperature and modifies the glow time. This might be one good reason to mount it with the Banks bracket and keep it close to the engine instead of out on the fender platform where it might get cold quickly while the engine stays warm.

https://www.ford-trucks.com/forums/1...-tutorial.html

 

The new style controller uses the resistance of the glow plugs themselves to calculate temperature, and thus glow time. As the temps go up, the resistance increases. This is why when you lose one or more glow plugs, the effective resistance increases, and the glow time is shorter... so one or two bad glow plugs can prevent others from getting hot enough to fire.

I've found that the "worst combination" - spade-style "12V" glow plugs, plus a 7.3 controller(Actually, just the relay and loading resistor(the big metal zig-zag piece)) hooked up to a manual push button works nicely for me. I hold the button more like 12 seconds(due to the extra resistances involved, the GPs take longer to heat to the same temps), but it helps keep the GPs from dying.

 

Thanks for the clarification on how that actually works. Will the 12v spade plugs work with automatic controller function or only as a push button set up? As far as saving the GP's there is the video in the sticky thread from the guy who tried to burn out a 12v spade plug on a 6v controller and gave up after 12 minutes of continuous glow. I can see the appeal in that, I just wonder if it gets hot enough for extreme cold starts... (?)

 

Only as a manual. The automatic controller will see too high resistance and not heat them near enough.
To be fair, I've burned them up myself with a minute or so, in the engine, when it was really really cold. Probably because there is less heat transfer than out in the open.
Also, I have really good wiring to each glow plug(individual 12ga wire from the controller to each), so there is less resistance there.
I've gotten them hot enough to kill them, so I'd say the answer is yes.

Thing is, though... when it is that cold, glow plugs aren't usually the problem. It's fuel delivery.
Last year, when it got extremely cold, I burned the glow plugs up trying to get it hot enough. And it never even popped.
I had to sit there spraying ether in the engine, cranking, ether, etc for several *minutes* until it finally took off... I think the fuel was gelling or something.
That was before I rebuilt my engine, but when it wasn't quite so cold, it would fire right off no problems.

 

Ok today I opened the hood and checked the glowplugs, 4 dead, 4 good. Pretty impressive it stil starts at -5 celsius without any major problem, which tells me the compression should be good. Spade conectors, the spare engine I have has spades as well, so I need the glowplugs.

 

I know some people hate them, but I've used the Wellman/DieselRX DRX00088 glow plugs.
This last week, I checked mine and found 1 dead out of 8, after about a year... and I'm pretty sure I held my button on too long because I know when it started rough(er) than before*(also, the one which failed was Cyl 1, which has the shortest length of wire in my wiring scheme, so it would get hottest).

83 96 Ford Diesel RX Glow Plug Set of 8 DRX00088 | eBay
Set of 8 for $60, Czech republic is in the "ships to" list, but I don't know the shipping cost.


*Note: As you've probably noticed, with fewer glow plugs the engine may still start... but it'll smoke and miss for a few seconds until the cold cyls warm up enough to fire.