Glow Plug Mystery

[Pianoman]

Hi, all! I've got an 86 F250 6.9. Low miles, just over 100k, T19, stock as they come, except for the manual glow plug conversion. The truck had some issues when I bought it, one being that the glow plugs were out. New Berus, and it fired right up when cold. About 10 times. Then nothing. No problem! How about new AC Delco 12G or whatever those were! No problem. Fired right up when cold. About 25 times. These went bad more slowly, maybe because I was paying closer attention. Now, a set from somewhere or another, Wellmans apparently. These are also starting to fail. I've reduced my glow times to 5 sec max, but this doesn't seem to be making a difference. Cold starts get harder each time. A TINY shot of ether into the top of the snorkel lights it up with no fuss every time (no glow for this of course....)
Any ideas?
My pal wrenches on his Benzs, and he thought the plugs should be clean after being in use. Mine come out sooty pretty fast. I thought maybe I need new injectors? IP has only 30k, O rings were done on the injectors, but they are probably OG, with 116k on them now.
This is my hauler, not my commuter, but I need it for LONG trips when the time comes.....

 

[79jasper]

Get the beru plugs.
Also looks into the solid state gp setup.


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[madpogue]

What relay are you running?

 

[jas88]

Mine did similar to yours, replaced GPs (with Berus) and it started pretty good, put in electric fuel pump and starter, it started very good during the winter. Then one day, ****, it didn't want to start anymore. I decided I did not trust the GP wiring, it was all original (my motor is an 88) so I replaced all the GP wiring from the solenoid (on the fender) to the GPs, also replaced the relay. Starts faster than ever now, although it's not as cold here anymore as it was a few months ago. Time will tell, but it's good for now.

 

[FarmerFrank]

I decided to try wellmans and got one 10 second cycle out of them. Berus from now on.

 

[gandalf]

Manual glowplug conversion---they're great when you believe in them and have them working well. There's all kinds of room for error and problems also. That's the first place I'd look.

Are you actually burning out glowplugs? Or do they just quit working? You've pulled out the glowplugs every time you've changed them. What do they look like? Have you tested the ones you've pulled to determine whether they've really burned out? You DO change all 8, don't you?

Could you take a good look at the controller for us? Diagram it, tell us where each of the wires goes. Identify each and every wire on the controller, color and location. Where is the controller getting it's power? Trace that power cable back to a connector and take a good look at that.

We love good pictures, if you can get some onto the forum. Many here understand pictures better than the written word.

 

[ToughOldFord]

He converted to manual already, the operator is the controller with the manual setup. Factory controller does nothing.

 

[icanfixall]

Its found that Motorcraft Beru ZD9 glow plug work and they work well for a long time. Many have tried others only to find out they wasted their money doing so. Once again its ZD9 beru from Motorcraft. Also the solid state controllers are fool proof most of the time. Some do end up with issues but usually its not the controller.

 

[Pianoman]

Manual glowplug conversion---they're great when you believe in them and have them working well. There's all kinds of room for error and problems also. That's the first place I'd look.

What kind of problems do you see? The setup is so dead simple, uses the same solenoid, just trips it off with a manual switch rather than an automatic one. My setup is big wire from the battery to the solenoid, big wire from the solenoid to the GPs. Little wire from the battery to the switch, little wire from the switch to the relay input terminal. The relay looks identical to the starter solenoid, but it's blue.

Are you actually burning out glowplugs? Or do they just quit working? You've pulled out the glowplugs every time you've changed them. What do they look like? Have you tested the ones you've pulled to determine whether they've really burned out? You DO change all 8, don't you?

My test light tells me if they work or not, after cold starts tell me first that they aren't working. Berus were installed just before I bought the truck, by the PO's mechanic. After these quit, I did some reading. They are not self regulating, and depend on the controller to avoid overheating. Too many full 10 sec. glow cycles with the switch, and they all tested dead. Second set were self regulating, but I killed one in pre-install testing, so only 7 went in. Many of these AC Delcos swelled a little and cracked on testing, but withstood 3 30 second test cycles and still got hot. Not for long. Then the set from somebody, wish I could remember, who tests them again after the factory. Wellman's according to somebody on this forum, if I remember correctly. Short on time, didn't test these myself, and they are still working *I think*. I'm keeping glow cycles to 5 sec or less to try and keep these alive. When cold soaked at 50 deg or so, it seems like I'm not getting all cylinders hot with 5 sec. When it's 75deg outside, 5 sec. gives me the 1/2 second crank time I want, she lights off as fast as I can turn the key.

Could you take a good look at the controller for us? Diagram it, tell us where each of the wires goes. Identify each and every wire on the controller, color and location. Where is the controller getting it's power? Trace that power cable back to a connector and take a good look at that.

We love good pictures, if you can get some onto the forum. Many here understand pictures better than the written word.

I'll get some snaps one day soon. I don't get under the hood of this guy so often...

Thanks for all the input!

 

[ToughOldFord]

10 seconds won't kill a GP, 10 seconds is what I do with my manual setup. Factory is something like 15-18 seconds.

Your problem sounds like an odd one, but the cycle time isn't the cause.

 

[icanfixall]

I'm thinking you are not getting the amps and current flow to the controller to lite off all the plugs. Our main engine wire harness connector thats found on the passenger side of the engine fender well usually is corroded or melted. They need to be checked for melting or corrosion. Find the 2 yellow wires in the connector. They are the only wires that are connected to one wire lug on both ends of the wires. Thats the fender solenoid and the controller. Its best to remove that wire and run a direct heavy 6 gauge wire to feed power to the controller. In very worst cases that plug melts. Catches fire and your truck will burn down. My truck started one day and I saw a puff of black smoke come up from that side of the engine out under the hood to fender joint. I thought I burned up my starter. Nope. Opened the hood and looked around. finally found the melted harness connector. I fixed that fast quick and in a hurry.

 

[ToughOldFord]

I'm thinking you are not getting the amps and current flow to the controller to lite off all the plugs. Our main engine wire harness connector thats found on the passenger side of the engine fender well usually is corroded or melted. They need to be checked for melting or corrosion. Find the 2 yellow wires in the connector. They are the only wires that are connected to one wire lug on both ends of the wires. Thats the fender solenoid and the controller. Its best to remove that wire and run a direct heavy 6 gauge wire to feed power to the controller. In very worst cases that plug melts. Catches fire and your truck will burn down. My truck started one day and I saw a puff of black smoke come up from that side of the engine out under the hood to fender joint. I thought I burned up my starter. Nope. Opened the hood and looked around. finally found the melted harness connector. I fixed that fast quick and in a hurry.

That's the relay you are talking about Gary, the controller is behind the D/S head and is not part of the GP circuit, it just tells the relay when and how long to activate the GPs.

 

[icanfixall]

ok.. Sorry but I thought we were referring to the solid state controllers and not the controller in the head.

 

[gandalf]

There are, really, only two problems with the manual gp system, I think. People with them incorrectly, and people often let the plugs glow too long. A 10 second glow should be no problem. My factory setup glows for about 15. Stick with the Beru glowplugs. People here have tried all the others, and found that Beru works best.

When my gp system failed it didn't take too long to find the problem, with a bit of help. The two yellow power cables had melted and shorted at the connector at the driver's side fenderwell. Picture attached.

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The yellow cables were cut, capped, and a new power source run from the passenger side. This is apparently not an uncommon problem.

 

[Black dawg]

There is a bosch plug that works very well with a manual set up, if you are interested, I can get you the part number. I have been using them in my own, and others trucks (customers) for about 4 years now with NO failures.