Glow Plug Idea Question

[Poorman]

I've owned this 86 f350 6.9 for about 30 years. I always seem to be fighting with hard, smoky starts. I went to manual button 5 years ago and it's been better. I run the plugs for 8 seconds and then crank, I always feel like it needs more but I'm so afraid that I will burn them that I just let it smoke and then with a couple 2 second jabs on the button it cleans up. Last week after sitting for 2 weeks in hunt camp it smoked on startup really bad, so I checked the plugs when home and found just one bad plug. It just seems like a really poorly engineered system that can burn plugs so easily. Yes I run the Beru's. Here's my question, Why can't I just lower the amperage way down on the system to the point that they won't burn out, yes I might have to leave them on for a minute or two but I'm fine with that, it only only gets started once a month. I got the idea watching a video a few years ago. A guy was trying to show how durable the berus where, he hooked them up to a battery charger and left them glowing for like 30 minutes and they never burned out and looked to glow bright. So I started running my manual switch for 15-20 seconds and it started great--for a few times and then no start, the plugs were burned out.(laugh here). So I did the test on some new plugs again and found that I could leave one on the battery charger for half an hour and it wouldn't burn out, but if I hooked it up to the engine battery(more amperage) they would burn out in 15-20 seconds. They don't burn out they just won't work again after cooling down. So why not find a way to lower the amperage to the system and be able to run the plugs long enough to really warm the chamber and not have to worry about over heating the plugs? Thoughts???

 

[Black dawg]

bosch 80034 plugs will fix you up. hold them on as long as you need to. I have not seen one burn out yet.

The berus are only durable when used with a properly functioning controller

 

[The_Josh_Bear]

I've owned this 86 f350 6.9 for about 30 years. I always seem to be fighting with hard, smoky starts. I went to manual button 5 years ago and it's been better. I run the plugs for 8 seconds and then crank, I always feel like it needs more but I'm so afraid that I will burn them that I just let it smoke and then with a couple 2 second jabs on the button it cleans up. Last week after sitting for 2 weeks in hunt camp it smoked on startup really bad, so I checked the plugs when home and found just one bad plug. It just seems like a really poorly engineered system that can burn plugs so easily. Yes I run the Beru's. Here's my question, Why can't I just lower the amperage way down on the system to the point that they won't burn out, yes I might have to leave them on for a minute or two but I'm fine with that, it only only gets started once a month. I got the idea watching a video a few years ago. A guy was trying to show how durable the berus where, he hooked them up to a battery charger and left them glowing for like 30 minutes and they never burned out and looked to glow bright. So I started running my manual switch for 15-20 seconds and it started great--for a few times and then no start, the plugs were burned out.(laugh here). So I did the test on some new plugs again and found that I could leave one on the battery charger for half an hour and it wouldn't burn out, but if I hooked it up to the engine battery(more amperage) they would burn out in 15-20 seconds. They don't burn out they just won't work again after cooling down. So why not find a way to lower the amperage to the system and be able to run the plugs long enough to really warm the chamber and not have to worry about over heating the plugs? Thoughts???

I think what's happening is one of two problems:

1. Copy-cat Motorcraft products seem to be at an all-time high right now and this could be the reason for the failures. But the copies are pretty darn good in some cases, it's not as easy as I thought it would be to spot a fake.

2. The durability of genuine Beru plugs has gone way down. I've heard of many reports here that brand new Beru's/Motorcraft plugs are burning out easily in just a few years or even the same year.

That said, good Beru plugs will not simply burn out if you give them a few bonus seconds. I've had the same set in my rig for longer than I care to remember, 6-7 years, maybe more...and I use a manual button. In the cold weather I'll run them 13-15 seconds and freezing or below 20 seconds.

So whatever the reason is that we are having trouble with these plugs burning out, other members are figuring out other plugs to switch to.

I've never heard anyone suggest current-limiting these plugs since they are supposed to be self-limiting but it's a good idea. As you said it would just take longer, wouldn't hurt anything. Not sure how to do go about that-- what were you thinking?

 

[Poorman]

Thanks for the replies, I'm researching and reading about the bosch plugs, that could be worth a try. It's fun to think out of the box a little and that's why I'm asking these questions. "what were you thinking"? well electrical is my weak spot for sure so I was hoping someone with more wisdom could tell me how this could be done, or why it wouldn't work. It just seems like, if you burn out a couple glow plugs it will cause the remaining ones to fail prematurely, presumably from too much juice and overheating. So why not do the reverse and add a few plugs to the system, wouldn't that cause the plugs to underheat and last longer? That's what I'm thinking, just looking for a more sanitary way of doing it.

 

[Big Bart]

Some other thoughts.

The glow plug get hot, so that will take a toll over time. The glow plug design controls the amperage, so not sure how you can alter. Also if you throw less amps I believe it will heat up less.

Also keep in mind that it is in the mixture/ignition chamber, so if your egt’s go up so does the heat on the glow plug. So watch your egts, if frequently high that could be part of your issue.

To that point keep track of which plugs burn out, if the same cylinder keeps having an issue a bad injector, bad wiring, bad port on the IP, or compression issue could be part to blame.

Also bad connections can cause higher amps. Higher amps can cause more heat. So make sure all your glow plug wiring is tight, right, and clean.

Guessing you have a momentary button, but some have put a on/off switch and left it on or bumped it on. Just one time might cook a glow plug or two.

Now I have the 7.3, but my controller stays on for 10-15 seconds when the engine is cold but its 80 degrees outside. So 8 seconds in 40 degrees might not be long enough. You also could grab a spare gp and hook it to the gp power connector and use a decent size wire to ground the threaded part To the engine. Then see how hot it gets after 8, 10, and say 13 sec. You should be able to see the point of diminishing return.

Lastly IP timing and the timing advance have a lot to do with easy starting. So make sure your timing is set right! Wrong timing can also cause your engine to run hotter, that would effect glow plug life too. Make sure your advance works when the engine is cool. It’s like the members say, your engine when cold will start quickly and clatter much louder and over 30-60 seconds it quiets down. When your timing is off this is little to non-existent.

Hope that leads you in the right direction.

 

[Brody]

I just put a 7.3 into my bronco and it will not start unless I do 12 seconds plus. I checked em and all plugs are good. I don't have long term data but longer burns are working for me

 

[franklin2]

Are you guys embarassed or something because your truck puffs smoke when it starts? They are after all the old school diesels and will smoke on cold start up. As long as it starts, I use my manual switch as little as possible.

 

[Farmer Rock]

Are you guys embarassed or something because your truck puffs smoke when it starts? They are after all the old school diesels and will smoke on cold start up. As long as it starts, I use my manual switch as little as possible.

Same here. My trucks always popped off after 10 seconds on the GPs. I like the smell of diesel in the morning, so I don't care about a little smoke,lol

 

[IDIBRONCO]

I always seem to be fighting with hard, smoky starts.

Does "always" mean every time that the engine starts? If yes, then I feel that you should check your IP timing.

Last week after sitting for 2 weeks in hunt camp it smoked on startup really bad,

Since it was at hunting camp, I assume that the outside temperatures were cold. These engines always smoke at first when it's cold outside. It can look pretty bed. The smoke should clear up after the engine run long enough to build up enough heat in the cylinder to completely burn the fuel. That only takes a few seconds to a minute or so depending on how cold it is outside.

 

[Lonewolf182]

You should be able to put a resistor in series with the glow plugs to lower the amperage. But i haven't got a clue as to how to pick the right sized resistor.

I use a manual button for my glow plugs.
On cold days I'll press for 8 seconds. Lift off and give the engine 5~10 seconds to suck the heat out of the plugs. Then hit the button for another 8 secs. I've never had to do it more than 3 times.

 

[TexasTruck]

If my engine doesn't smoke on startup I start suspecting something is wrong.

If you want some good entertainment YouTube has videos of older locomotives doing cold starts.

My truck doesn't smoke and throw flames like that but if it did that would be very cool.

Some times when they don't spray for mosquitos I just start my truck and let it warm up.

 

[Poorman]

Thanks everyone.
Bart, I replaced pumps, injectors, returns, about 25k ago and I never let my exhaust temp needle touch the 1000 mark, I shift and enjoy the scenery. The advance works fine, very annoying until it pops off, usually a mile or so (slightly downhill). I do worry about those spade connectors on the GP's they just don't seem positive enough, I'd like to hear a snap. Probably should replace, I'm sure they're stock.
Franklin, I know smoke, I've seen it all, don't mind a good puff on start but when there are dead cylinders and the trucks shaking and you can be seen from ten miles off it's embarrassing. If governor Kate ever saw it she would ban us all!
Bronco, No, it's not always, but does seem to be migrating there, starts clean on a heater, colder =worse
Tex, I'll check out the locomotive video, sounds good
Lonewolf, I've been reading about resisters and trying to understand it's uses. I'm going to experiment this week with some 6 volt battery's, my brother (farmer) has some spare tractor battery's. I'll hook them to the GP system and wire in a 9th plug so I can watch and just play with it.

 

[Kristov]

Old diesels just smoke on cold start because they do. I remember my mom's neighbor's work truck covering the entire neighborhood in diesel smoke when we had snow simply because it was cold. Mid 90's Dodge 3500 if you're wondering what it was.

 

[Poorman]

Here's an update on what I've been experimenting with. I couldn't get the 6 volt battery's to charge so I took a 60 foot piece of braded # 12 wire and hooked one end to the glow plug harness and the other end to the glow plug solenoid, pulled one plug and clamped it to the engine block so I could watch it. I got a reading of 11.55 volts before I put in the wire and 5.95 with the wire installed, the wire is acting as a resister. At 11.55 volts the plug that I could see took about 4 seconds to start turning red and would max out and stabilize at about 10 seconds. With the wire installed it took about 15 seconds to start turning red and maxed out at about 25 seconds. So I tried starting using 30 seconds then a minute, then three and finally I held the button for 10 minutes, each time on different mornings at about 40 degrees. Each time it fired right up, but smoked excessively. I checked the plugs after each burn and they were fine. So I think the plugs were hot enough to fire it up, but not hot enough to make a clean burn. So I shortened the wire to 30 feet, which gave me 7.95 volts, it starts turning red at about 10 seconds and is bright after 20. So this morning, 32 degrees out, I held the button for 30 seconds and started cranking while keeping the button down for another ten seconds. It fired right up and smoked about half of what its been doing, so I think a little extra voltage made more heat and a better burn. Tomorrow I'm going to let them glow for 3 minutes just to see how durable they are with 7.95 volts. (beru's) Not sure where I'm headed with this, I guess I'll know when I get there.

 

[Big Bart]

Since smoking is part of your concern, perhaps see what running them for maybe 30 seconds more with the truck running does for the smoke. Starting the truck when you think they have first turned red to avoid over heating the glow plug. The newer controllers cycle the glow plugs on and off once hot to help keep them warm for a few seconds after telling you to start the engine.

Also there could be a valve seal leaking that is causing an oil drip once the engine is turned off that you just have to burn off at start up that is adding to the smoke. The glow plugs may help but will not make up for excessive oil burning in the cup.

You may want to clean or replace your cdr valve, if not working 100% could also be allowing some extra oil into the intake system. Perhaps adding to a smokey start.

But now you know what it will take on cold days to get your glow plugs to the right heat. (Limit the smoking) So that alone will have been worth the experiment. Most on this site will never have watched a glow plug glow.(Like me just assumed it does, thus the name.). Just spend time trying to find the dead ones when the controller is not working.

You may also want to try your experiments in conjunction with your block heater. Many members with a broken glow plug system find this an effective way of starting till the fix their glow plug system.

Another experiment could be unplugging one glow plug at a time each on a separate day to see if one creates more smoke when off than another. Helping locate a compression, ring, valve, injector, glow plug, wiring or CDR issue. To get good results outside temps would have be relatively consistent, say +/- 5 degrees.

BTW thank you for sharing your results we all are learning from your experiment.