Finally got around to testing, and then replacing the glow plugs.. 4 stuck.

MJGenay said:

One of those existing fusible links broke again. I don't think it melted, just brittle. At any rate I cut them out and attempted to solder them in. Turns out the soldering gun that hasn't been used in 20 years but has followed me around the country doesn't work. It is good at burning me, bad at melting solder... so crimped again. We'll see how it goes with these new links... I used 14 gauge.

Anyone know what exactly the glow plug relay is supposed to do after the WTS light goes out? Before I changed my plugs, once the light went out (~15 seconds normally), the relay would cycle on and off for awhile. Now, the WTS goes out after 15 seconds, the glow plugs appear to stay on for about another 30 seconds (looking at the battery gauge on the dash), then it clicks once and goes off. How's that sound? Working as it should?

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Firstly 15 seconds is a good sign. The cycling it does after the WTS light goes out is called "after glow". It just helps get a tiny bit more burn outta the fuel in those cold early moments, and therefore helps the engine keep going as it should.
So you were saying you waited until the afterglow cycle was over, too? If so, it won't start like that.
The fact that it's not afterglowing any more is odd. I ditched my controller long ago so I'm not super familiar with them, someone else will have to tell you what that means. Clearly the controller is working to some extent if you have a 15 second glow time.

5w-40 will let the engine turn faster in these cold temps, I hear lots of good things about it. We need every RPM we can get when cranking over. If there is a chance you can take a short video of your cranking speed we could chime in there, too. It should be turning over faster than you can count, even in your head.
You *could* have perfectly fine GP's and not enough cranking speed in the lower temp range. Hopefully the oil fixes that, potentially think about a DB electrical starter upgrade. But for now keep up the good work!

Powermaster Starter thread

It should cycle on and off after the light goes out. You should try to start it once the light goes out, and the controller will cycle the plugs on and off after the engine has started. This is just to reduce the smoke out of the tailpipe once started and keep the tree huggers happy.

Since it's staying on solid after the light goes out, I suspect your relay in the controller is sticking. Just like the new starter solenoids you buy now, I bet these controllers are also using made in China relays, and they do not put any good metal in the contacts. So they like to weld together and stick. There have been major problems with new starter relays sticking and not turning off after the key is released. The relay in your controller is no different than a starter relay.

Not sure if you can buy a higher quality relay and retro fit it in the controller or not.

And you might want to check all your glowplugs again. Glowing them that long may have burnt some of them out. Glowing the plugs that long and getting them that hot should make the engine fire right up, unless some of them are burnt out from this problem.

Well shoot.

Okay thanks guys. I'll check the plugs again. I was starting to wonder about that relay.

What is weird is to the best of my knowledge the relay was working perfectly with the old, bad, plugs. WTS would turn on for 15 seconds and once it would turn off the relay would begin to cycle.

Not sure if I can replace the relay or if the manufacturer fused it to the controller. PO replaced both about a year and a half ago.

You can replace just the relay and not have to buy the whole Controller assy.

Here is some info on the relay I copied off an International truck site.

Mechanic Tip:
If your motor is hard starting this relay could be your problem. Got a lot of smoke after starting? To test your relay, connect your test light across the two little terminals and activate the glow plugs by turning on the ignition. If your test light comes on, the signal to the relay is good. Now connect your test light's clip to engine ground. With the ignition off again, touch each of the big terminals on the relay. One will cause the test light to light - this terminal is connected to battery positive. Now, cycle the glow plugs on again. The opposite big terminal should now be getting power. If not, the relay is bad.

Reading through this thread, you are like a dog digging for a bone.
I understand having it work as factory if others drive your truck. Most don`t know the difference between 10 sec and 10 min.

I have my 86 (different type Controller) wired manually, Thurs. night got down to 10deg, yesterday (FRI) got all the way to 38. Fired her up about noon time, counted to 10 sec with spring toggle held down. Got one R-r on the Starter and she lit right off. Of course she sounded like she was crushing rocks.... Push the toggle another 5 sec....wait 10 sec or so and hit it again, and she gets enough heat to start to smooth out. That would be like your after glow.

Just turned 331K on the ODO. Have no idea condition of Pump and Injectors, bought it with 192K 8 yrs ago.

Sounds like you have it zeroed in on the big connector and wiring.


Goat

Okay guys. I'm kinda sure it may have been those fusible links. They were connected enough to send some voltage but not enough amperage maybe? At any rate I finished changing the oil this morning and decided to try starting her. It had been in the garage which was around 30ish and I left the door open to the outside which was around 15ish for an hour or so. Figure the engine should've been decently cold. It started in about 2 seconds of cranking, I started cranking as soon the WTS light went off. That is the best cold start I've ever had at those temps, hell its good for 50 degrees. I do believe I have a slight air intrusion leak somewhere as I do need to floor it when cranking. I'm going to have to give it another go tomorrow morning and see what happens... trying to not **** off the neighbors but oh well.

Here's the kicker, I decided to bench test the old glow plugs for ****s and giggles. I maybe was moving from one to the other too fast. While after a couple seconds each reads around .9 ohms if I stay on them for a few more seconds they all (except 1) drop down to .5 ohms. Son of... so I'm figuring I didn't leave the meter on them long enough and they might've been okay. Duh...

For what its worth I realize I'm like a dog digging for a bone but with the limited knowledge I have that's the best I can do... it just hurts the wallet a good bit. I don't like to give up.

Finally, as this is my first diesel, let me say just how amazed I am at what 15w40 is like at 30 degrees... ITS LIKE MOLASSES. Very glad I changed it as that couldn't have been helping anything and probably not helping engine life.

Additionally I am glad I changed the 650 CCA batteries to 850 CCA's. Yeah, that was $400... but it is what is called for and made a huge difference in cold cranking speed even before changing the oil to 5w40.

I will report back with further progress but I think I need to let this get cold overnight to actually test. I'm also going to take a video of the cranking and initial start.

Pressing the throttle some is the standard starting procedure from Ford. You are supposed to press the pedal half way when the outside temp is above 32 degrees F, and all the way down for below 32 degrees temp.

A fuse link is just like a standard fuse. It is either OK or it is NOT. No half-way or just a little voltage. It is working or it is NOT.

DaveBen said:

A fuse link is just like a standard fuse. It is either OK or it is NOT. No half-way or just a little voltage. It is working or it is NOT.

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There IS a time when a fuse link can crack(not melt from overcurrent) and give a positive voltage reading but cannot handle much amperage, or handles it sometimes and not other times. I wouldn't know this except that it's happened to me on this truck with two different fuse links.

The_Josh_Bear said:

There IS a time when a fuse link can crack(not melt from overcurrent) and give a positive voltage reading but cannot handle much amperage, or handles it sometimes and not other times. I wouldn't know this except that it's happened to me on this truck with two different fuse links.

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Yeah, per the multimeter it was pushing the voltage to the relay, everything read correctly voltage wise. I'm not sure if it is possible to, or if it is I don't know how, to read amperage with that.

There are some other fuse links by that passenger battery. They don't seem to be in ideal condition. I'm not actually sure where they go but I believe it is a four pack of them (the ones heading to the glow plug relay were two singles, one each going to each black/orange wire.) I think I'm going to replace those four too. I have a soldering iron on order from Amazon... seemed well reviewed and less than $20. If those I crimped last night hold up I am going to just crimp new fuse links into those wires as well, if they don't it all comes apart and all gets soldered.

franklin2 said:

Pressing the throttle some is the standard starting procedure from Ford. You are supposed to press the pedal half way when the outside temp is above 32 degrees F, and all the way down for below 32 degrees temp.

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Okay that is good to know. I was thinking of it in terms of a carbureted vehicle where it means things are out of adjustment or you lost your prime. To be clear normally I am supposed to press the pedal while cranking? I still wonder if I might have some air intrusion though, all the injector caps for the return lines are new from PO but who knows. I do know I have to drop those tanks at some point because my vent lines are shot (takes 20 minutes to fill two tanks barely holding the gas pump) and because I think my pickups have broken too. Not sure if I might have a leak further back on the system.

You press the pedal while cranking. It must signal the injection pump to add more fuel, that is a guess on my part.

I don't think you have any air intrusion. If you did the engine would start right away like it normally does (for a diesel that is) and then suddenly stall. Then it will not start without a lot of cranking. That is because the air gets into the front of the pump and the supply lines, but it does not affect the fuel already in the hard injector lines. So it runs just for a little bit on the fuel in the injector lines and then stalls out when the air hits the injector lines.

I just went out and shot a picture of the start instructions. My first bullnose IDI didn't have them but this 87 did.

franklin2 said:

You press the pedal while cranking. It must signal the injection pump to add more fuel, that is a guess on my part.

I don't think you have any air intrusion. If you did the engine would start right away like it normally does (for a diesel that is) and then suddenly stall. Then it will not start without a lot of cranking. That is because the air gets into the front of the pump and the supply lines, but it does not affect the fuel already in the hard injector lines. So it runs just for a little bit on the fuel in the injector lines and then stalls out when the air hits the injector lines.

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If not air intrusion I have some kind of an injector issue. I'll take an video tomorrow on startup. Its been in the garage the past couple days as I have been fixing a few other things. Its parked in the driveway tonight so tomorrow morning should be a decent test.

WrenchWhore said:

I just went out and shot a picture of the start instructions. My first bullnose IDI didn't have them but this 87 did.

You must be registered for see images attach

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Thank you! That's pretty cool. Kinda surprising that its supposed to be floored under certain conditions when starting.

franklin2 said:

I don't think you have any air intrusion. If you did the engine would start right away like it normally does (for a diesel that is) and then suddenly stall. Then it will not start without a lot of cranking. That is because the air gets into the front of the pump and the supply lines, but it does not affect the fuel already in the hard injector lines. So it runs just for a little bit on the fuel in the injector lines and then stalls out when the air hits the injector lines.

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MJGenay said:

If not air intrusion I have some kind of an injector issue.

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The above describes fuel drain back, not air intrusion. Air intrusion only happens when the engine is running and it affects the way that it runs.

IDIBRONCO said:

The above describes fuel drain back, not air intrusion. Air intrusion only happens when the engine is running and it affects the way that it runs.

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I apologize, I don't quite understand. What describes a fuel drain back? Stalling after start?

MJGenay said:

What describes a fuel drain back? Stalling after start?

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Yes. That is the symptoms of fuel drain back. What happens is that there is a slight leak so that the fuel system isn't 100% sealed. When there's no more incoming fuel to keep pressure in the system, then it drains back toward the fuel tank, usually slowly, taking several hours. Think of putting a straw into your drink. Put your finger over the end that's sticking up from the drink. Then pull the straw out. The liquid will stay inside the straw, representing a sealed fuel system. If you take your finger off of the straw, the liquid will drain back out of the straw. This doesn't affect the way that the engine runs.
Air intrusion is when air gets drawn into the fuel system while the engine is running. This will cause your engine to act like it's losing power and then getting a burst of acceleration. It will happen even if you hold your foot steady on the throttle. People get the two conditions confused, because they can be and often are related. As in one leak can cause both.
Air intrusion can only happen on the suction side of the fuel system. In other words, before the lift pump. Fuel drain back can be caused by a leak after the lift pump so that won't cause air to be drawn into your fuel system while the engine's running. The 7.3 fuel heater and a bad/leaking injector o-ring are two places that can cause fuel drain back without air intrusion.