Something isn't working right. When I turn the key on, I get momentary power to the plugs along with a very fast on/off/on/off clicking of the relay. This last about half a second, then I lose power to the plugs but the dash light stays on for the full 6 seconds or so. Same thing when I turn the key to start.

All relays, dropping resistor, plugs, etc all test out good with a ohm meter. Good charge on the battery, and I even pulled the relays and bench tested them.

My glow plugs worked great with the C223. The only variable is the plugs in this engine as I have it all hooked up as it was originally.

I have a diagram for this engine that shows no dropping resistor, sensing resistor, and only one relay. This is called the QOSII system. It must use 12 volt plugs and I'm pretty sure thats what I have and it is confusing my system that is supposed to have 6 volt plugs.

What I think is happening is the 12 volt plugs are attempting to pull too much power and something senses this and shuts off the power. The dash light staying on until timing out has me confused though.

Soooo.......to make a long story longer, what I am thinking about doing is using the 12 volt plugs (readily availiable here in the US) and an aftermarket controller. I don't want a button. I want everything to appear original unless you know what you're looking for under the hood. Plus some people that may drive this from time to time can't figure out a button.

I found THIS UNIVERSAL ONE that would work but is kinda bulky. Plus I don't really like how the temp sender attaches. But it's cheap and would work.

Then I thought about A FORD CONTROLLER. I am familiar with these and have one on my Ford diesel I could take off to experiment with. It's nice and compact and uses a regular temp sender in the water neck. My only concern is that it appears to have a sensing resistor of some sort, and would only having 4 plugs as opposed to the 8 it's designed for cause problems?

Ideas?????

Thanks guys

My system is wired exactly as yours is (unless I made a mistake somewhere), as I installed the control system from a C223 Trooper and connected it to my 4JB1's plugs.

It behaves exactly as you describe yours. I have not had the time to dig into this at all, but it is close to the top of my list now. The good news is that I have started the engine in some really nasty weather without the benefit of glow plugs (much colder than it ever gets in your part of the country, I am sure) and feel confident in the direct injection's design as being a good one for cold weather.

At any rate, in other threads (my conversion thread may have covered it, too) Jerry Lemond has listed some of the reasons the glow system will act like this. One reason is lack of power to the relays, if I recall correctly. This was the first thing I was going to check, as I did my own wiring and may have a bad connection. There were some other causes as well.

Failing that, it may be worthwhile to see if we could trick the controller into thinking it's got 6V plugs attached (if this is the cause of the trouble). If it's coming over the sensing resistor line, maybe adding resistance to this signal line would give the controller the reading it's looking for. This is just conjecture at this point, but it may work... unless I am picturing the system's function incorrectly.

Yeah glow plugs are not as necessary on direct injected engines. I'm not to worried right now as I plug my diesels in when it's that cold. But what if....?????

I am starting to change my opinion. I've been researching all night, and after hearing that yours is doing the same thing. I have a good understanding of the QOS system used on these engines. I know a (little) bit about AC current and believe the same rules apply to DC.

The way I understand it, the sensing resistor measures the current (amps) the plugs are drawing and uses that to determine the heat of the plugs. As heat goes up, so does resistance. Actually that should be the other way around, the resistance is what makes the heat. Either way, as they heat up the amps getting "through" goes down. That's what the sensing resistor picks up on and cuts the voltage back to 6 volts to keep from burning the plugs out.

So, 12 volt plugs should require half as many amps as a 6 volt plug (at 6 volts). This is why a 6 volt plug will heat so fast, and self destruct, on 12 volts. Just like a 240 volt AC electric appliance needing half as many amps to operate as it's 120 volt equal. There's a math problem I knew for that, but it has been lost.

Anyway, what I'm getting at is I don't think the (maybe) 12 volt plugs would cause this problem. I think they would work poorly, but should work.

I think I have other issues going on. I need to do a voltage drop test and check the resistance of the power wires. I think I have power supply issues....

This is all speculation, combined with a little bit of scattered knowledge, which can be a bad combo. We'll figure it out though......

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