Wait light/starting issues

[M1123 Greg]

First thing: I’m really starting to hate on this wait light

History:
i bought a non-running truck, got lucky put 2 batteries in and it started right up
drove it around a little locally while I waited for parts to get it inspected
one day it didn’t start anymore.......sigh
read about the glow plug issues these have and started there
replaced glow plugs, all measured bad btw - nothing
noticed that a high pitched whining sound that was present during wait light wasn’t happening anymore (buddy surmised this might be injection pump charging the lines in preparation for start, made sense to me but not sure)
decided to investigate fuel system, specifically fuel filter
fuel filter was bad, hogged up good ( apparently there was biological crap in fuel tank that got stirred up and sucked into fuel system when I drove it around). Good news nothing got through the main filter because the water separator was clean.
cleaned filter housing and got new filters
dumped fuel tank and flushed out with clean as best as possible
broke the fuel line before the filter
added new fuel and used the primary fuel pump to flush the line till I didn’t see chunks
reattached lines, filled filter housing with fuel to eliminate air
tried pushing out air by turning engine over, eventually started seeing white smoke out of tailpipe
unfortunately whining sound was not present during wait and wait light doesn’t go out
despite numerous attempts doesn’t start
decided to break fuel lines at injectors to potentially get rid of trapped air
at all the injectors I got a pulsating drip (was kinda expecting to see high pressure squirt)
I assume the primary pump was pushing through the injector pump And dripping into the combustion chamber thus causing the white smoke but it wasn’t enough for a start
it really seems like something electrical is going on that I don’t yet understand and holding out the injectors pump thus preventing start. Have a hard time believing the injector pump just stopped working and is bad.

i understand some of this might be wrong and I’m putting this out there to get to the bottom of this. the only thing I care about is getting it started, any help would be greatly appreciated. Feel like I was pretty thorough With air purge

 

[86humv]

Box under dash is probably bad....If glow plugs were all bad, and you changed them, but not the Box.....that sound you herd with start light on was probably the glow plugs burning up.

 

[Milcommoguy]

I would like to chime in.... BUT there's a bit stuff going on here. Would be a little helpful if was parked for years or barn find, auction site, last time it ran... Nothing too personal.

Glow plugs sure can be a problem. How did you get it started if they were bad. ?? Change and then started?? Got lucky here.

I have heard a whining from the PCB / ESSS box with low battery voltage.

White smoke signal out tailpipe could be a sign. Recheck glow plugs and voltage present during cycle time. DO NOT leave in RUN position... NOT for more than TEN seconds at a time ! if you suspect PCB / ESSS box has failed making this voltage test. (pull one of the plug lead and measure the voltage at the lead)
No voltage during the first 10 seconds.... Shut it off and start whining, as it sounds like "box time" $$$$ Could get lucky checking, removing batteries, reconnect and try again.

This is a common problem with questionable first time "starts" More history could help, but it sound like your going down the path to working out the gremlins.

Steel Soldiers... Open 24 Hours, CAMO

 

[Coug]

the injection pump on these is mechanical, so there is no "charging the lines" while waiting for it to start.

The amount of fuel going through the injectors each rotation is pretty small, so all you normally see is a drip when you crack the lines, because the way it injects is overcoming pressure inside the injector itself to cause a fine spray. Cracking the line makes it so it doesn't build pressure, it just acts as a small pump.

It's possible that it's still an injector/pump issue, but if you're getting smoke out of the exhaust during cranking it is more likely you have a glow plug or controller issue.

Always make sure your batteries are fully charged and in good condition before trying to troubleshoot a hard/no start, because these things don't like to start if they aren't cranking over fast enough. All it takes is one bad battery cell or one low battery to make starting very difficult. Add to that the glow plugssucking down power before cranking and it's a no-go.

 

[Elijah95]

Something that might help you here, I’d strongly consider installing a supplemental ground harness. I didn’t know it at the time, but the bad grounding on these trucks can do some stupid stuff, not only did it kill headlights on my truck, but leave other lights in tact, but it killed gauges and killed my glow plugs.

Where power goes in, it must have a path out.

Here’s my dinky video on it, it may or may not be your root cause but I promise it can’t hurt anything.

Sent from my iPhone using Tapatalk

 

[M1123 Greg]

Something that might help you here, I’d strongly consider installing a supplemental ground harness. I didn’t know it at the time, but the bad grounding on these trucks can do some stupid stuff, not only did it kill headlights on my truck, but leave other lights in tact, but it killed gauges and killed my glow plugs.

Where power goes in, it must have a path out.

Here’s my dinky video on it, it may or may not be your root cause but I promise it can’t hurt anything.

Sent from my iPhone using Tapatalk

Thanks for replying, I should have mentioned in original post that I did do a supplemental grounding harness after reading about it on this site.

 

[Elijah95]

Thanks for replying, I should have mentioned in original post that I did do a supplemental grounding harness after reading about it on this site.

Great stuff, well I’m sad to say that probably won’t help now


Sent from my iPhone using Tapatalk

 

[M1123 Greg]

the injection pump on these is mechanical, so there is no "charging the lines" while waiting for it to start.

The amount of fuel going through the injectors each rotation is pretty small, so all you normally see is a drip when you crack the lines, because the way it injects is overcoming pressure inside the injector itself to cause a fine spray. Cracking the line makes it so it doesn't build pressure, it just acts as a small pump.

It's possible that it's still an injector/pump issue, but if you're getting smoke out of the exhaust during cranking it is more likely you have a glow plug or controller issue.

Always make sure your batteries are fully charged and in good condition before trying to troubleshoot a hard/no start, because these things don't like to start if they aren't cranking over fast enough. All it takes is one bad battery cell or one low battery to make starting very difficult. Add to that the glow plugssucking down power before cranking and it's a no-go.

Great info here, I appreciate the insight on the injection pump. My batteries are actually brand new military Deka batteries (who is the OEM supplier I’ve come to find out) they have a 2/21 manufactured date on them. The glow plugs are also brand new. If it is a controller that I need to replace so be it but I would like to be absolutely sure that is what it is. Any suggestions how that could be confirmed?

 

[M1123 Greg]

I would like to chime in.... BUT there's a bit stuff going on here. Would be a little helpful if was parked for years or barn find, auction site, last time it ran... Nothing too personal.

Glow plugs sure can be a problem. How did you get it started if they were bad. ?? Change and then started?? Got lucky here.

I have heard a whining from the PCB / ESSS box with low battery voltage.

White smoke signal out tailpipe could be a sign. Recheck glow plugs and voltage present during cycle time. DO NOT leave in RUN position... NOT for more than TEN seconds at a time ! if you suspect PCB / ESSS box has failed making this voltage test. (pull one of the plug lead and measure the voltage at the lead)
No voltage during the first 10 seconds.... Shut it off and start whining, as it sounds like "box time" $$$$ Could get lucky checking, removing batteries, reconnect and try again.

This is a common problem with questionable first time "starts" More history could help, but it sound like your going down the path to working out the gremlins.

Steel Soldiers... Open 24 Hours, CAMO

First couple answers:
This is a govplanet purchase I received in December
Last time it ran was about 4 weeks ago
I’m told Diesel engines don’t need glow plugs except in cold weather, which makes sense because it wasn’t that cold here at first when I was starting it.
the whining sound at low voltage totally makes sense, because it stopped happening when I got my new batteries and I haven’t heard it since.
I’ll get back to you on the remaining stuff....

 

[Milcommoguy]

OK where were we?? OH YEA, I bought a non runner..........

Note : You do need glow plug action unless the block is warm??? or you got lucky. DO NOT use either to assist unless under direct fire. (come clean here IF...)

You're in PA and I am in the Mojave Desert. I need glow plug action for first time starts. Say 50- 60 degrees. Once warmed up...Good for the rest of... "key word" summer day. Winter may need a little "glow action" every time out on a beer run.

If it was in my driveway... I would disconnect the batteries and wait some time. Some have had LUCK and the "BOX" has reset, or some other magic / BS. (what ever works I guess and if it ever toasted plugs... to the junk pile IMO)

In the meantime, check over ALL connections to the "BOX" . Engine and cab harness for loose, corroded, burnt, bent pins, wires. Check everything... note and fix. Might even see a rotted hose or leak and note that too. U get the idea. and make quality HumV time.

Any signs of the truck went for a swim ?? Water and electricity don't mix well if not addressed. The "BOX" has been known for filling with water. YEP...water proof = water poof.

I would be getting out the multi-meter (below) and running some simple tests. Re-check plugs for a very low resistance of 1.5 to 5 Ohms. Check batteries just to be sure too. Did or does the rigs voltmeter work? If correct it can be a helpful tool in the process of proper glow action. If ALL is correct it will show a voltage drop when the plugs energize drawing up to 100 AMPS pulling down the voltage a little, even on GOOD batteries. A kind of small window wiper action of the needle for the time plugs are cycling on and heating.

Quickie test for I can't wait, take a chance, feeling like viva Las Vegas. (proceed at you own comfort level) Re-connect batteries & check again... Pull Lever !

As stated do not leave the run - start switch in the RUN position for to long. when testing or guessing if "BOX" is good. IF the Wait is cycling On-1-2, Off-1-2, On-1-2, Off-1-2 and OFF and STAYS OFF you could be a lucky winner. Here's the catch... New, tested, good plugs and "BOX" if BUSTED ... you got about 20 seconds to shut it OFF and save $100 dollars. So.. do you feel lucky? NOT with me around.

Scientific test... Multi-meter on voltage, probe one of the plug leads and look for the voltage to cycle. If it does not or stays on you got a junk "box" and 20 seconds to collect 100 dollar, maybe.

At his point. Remove and replace both TSU and "BOX" This can be a $1000 hit. See pit boss for a credit. OUCH !

These are my 2 cents . Others may have more .

There are some "get out of Dodge" tricks... But you're not in my driveway, LOL.

Good luck , hope this helps CAMO

It's here somewhere............

 

[M1123 Greg]

OK where were we?? OH YEA, I bought a non runner..........

Note : You do need glow plug action unless the block is warm??? or you got lucky. DO NOT use either to assist unless under direct fire. (come clean here IF...)

You're in PA and I am in the Mojave Desert. I need glow plug action for first time starts. Say 50- 60 degrees. Once warmed up...Good for the rest of... "key word" summer day. Winter may need a little "glow action" every time out on a beer run.

If it was in my driveway... I would disconnect the batteries and wait some time. Some have had LUCK and the "BOX" has reset, or some other magic / BS. (what ever works I guess and if it ever toasted plugs... to the junk pile IMO)

In the meantime, check over ALL connections to the "BOX" . Engine and cab harness for loose, corroded, burnt, bent pins, wires. Check everything... note and fix. Might even see a rotted hose or leak and note that too. U get the idea. and make quality HumV time.

Any signs of the truck went for a swim ?? Water and electricity don't mix well if not addressed. The "BOX" has been known for filling with water. YEP...water proof = water poof.

I would be getting out the multi-meter (below) and running some simple tests. Re-check plugs for a very low resistance of 1.5 to 5 Ohms. Check batteries just to be sure too. Did or does the rigs voltmeter work? If correct it can be a helpful tool in the process of proper glow action. If ALL is correct it will show a voltage drop when the plugs energize drawing up to 100 AMPS pulling down the voltage a little, even on GOOD batteries. A kind of small window wiper action of the needle for the time plugs are cycling on and heating.

Quickie test for I can't wait, take a chance, feeling like viva Las Vegas. (proceed at you own comfort level) Re-connect batteries & check again... Pull Lever !

As stated do not leave the run - start switch in the RUN position for to long. when testing or guessing if "BOX" is good. IF the Wait is cycling On-1-2, Off-1-2, On-1-2, Off-1-2 and OFF and STAYS OFF you could be a lucky winner. Here's the catch... New, tested, good plugs and "BOX" if BUSTED ... you got about 20 seconds to shut it OFF and save $100 dollars. So.. do you feel lucky? NOT with me around.

Scientific test... Multi-meter on voltage, probe one of the plug leads and look for the voltage to cycle. If it does not or stays on you got a junk "box" and 20 seconds to collect 100 dollars. maybe

At his point. Remove and replace both TSU and "BOX" This can be a $1000 hit. See pit boss for a credit. OUCH !

These are my 2 cents . Others may have more .

There are some "get out of Dodge" tricks... But you're not in my driveway, LOL.

Good luck , hope this helps CAMO

It's here somewhere............

View attachment 829582

UNBELIEVABLE! The glow plugs are fried again. I know exactly when it happened too. A part of the story I failed to mention that is significant now. After I replaced the initial glow plugs but BEFORE I cleaned the fuel filter the truck started one time, and only once. I turned it off after only a minute because the wait light wasn’t going out and I was afraid it was burning up the glow plugs, apparently my concerns were justified. It never started after that.
So I have a new set of plugs coming and I’m crossing my fingers.
I still want to check some of the other stuff you Mentioned, I just haven’t had any time.
I’ll keep you informed, you’ve been very helpful thanks

 

[Action]

UNBELIEVABLE! The glow plugs are fried again. I know exactly when it happened too. A part of the story I failed to mention that is significant now. After I replaced the initial glow plugs but BEFORE I cleaned the fuel filter the truck started one time, and only once. I turned it off after only a minute because the wait light wasn’t going out and I was afraid it was burning up the glow plugs, apparently my concerns were justified. It never started after that.
So I have a new set of plugs coming and I’m crossing my fingers.
I still want to check some of the other stuff you Mentioned, I just haven’t had any time.
I’ll keep you informed, you’ve been very helpful thanks

can you unplug all of the glowplugs and hook a 24v bulb to one of the wires. Then turn switch to RUN. If the light doesnt go out, i would not hook up new plugs yet. Start looking for new PCB.

 

[Retiredwarhorses]

UNBELIEVABLE! The glow plugs are fried again. I know exactly when it happened too. A part of the story I failed to mention that is significant now. After I replaced the initial glow plugs but BEFORE I cleaned the fuel filter the truck started one time, and only once. I turned it off after only a minute because the wait light wasn’t going out and I was afraid it was burning up the glow plugs, apparently my concerns were justified. It never started after that.
So I have a new set of plugs coming and I’m crossing my fingers.
I still want to check some of the other stuff you Mentioned, I just haven’t had any time.
I’ll keep you informed, you’ve been very helpful thanks

What You just stated tells me the box is bad and the New set of plugs your about to install will work one time and grenade.
This Is not uncommon when the box fails, the glow plug timer won’t expire and continues to send 24v to the plugs after the wait light expires....had this issue on a truck last week.
To test the box...put a lead from your multi meter into one of boots, the other to ground, turn the key to wait, now see if the 24v drops off after the wait light extinguishes. An S3 EESS will drop off the 24v and show 5vdc for 2min, all other boxes will pulse 24v for 2min...but not a constant 24v.

 

[M1123 Greg]

What You just stated tells me the box is bad and the New set of plugs your about to install will work one time and grenade.
This Is not uncommon when the box fails, the glow plug timer won’t expire and continues to send 24v to the plugs after the wait light expires....had this issue on a truck last week.
To test the box...put a lead from your multi meter into one of boots, the other to ground, turn the key to wait, now see if the 24v drops off after the wait light extinguishes. An S3 EESS will drop off the 24v and show 5vdc for 2min, all other boxes will pulse 24v for 2min...but not a constant 24v.

Ok I’ll try the meter thing
Despite the cost of the box I’m very glad you seem so sure that it is in fact bad.

 

[M1123 Greg]

can you unplug all of the glowplugs and hook a 24v bulb to one of the wires. Then turn switch to RUN. If the light doesnt go out, i would not hook up new plugs yet. Start looking for new PCB.

Ya I plan to verify it, at least with a meter first. Light bulb could work too

 

[Milcommoguy]

The "old light bulb in the glow plug" trick. That works too.

At this point IMO... Wouldn't waste my time, fooling, wishing, guessing and $$$ with that "BOX"

Sometimes called "Smart Boxes" Cuz it smarts to have to buy another set of plugs, LOL

Time to kill ??? take it out, open it up, and snoop around for smoked parts. For most , nothing to see here... but for piece of mind, the smell of burnt stuff.
Upload some nice pictures inside and out and the part number. It may not fix it, But the guys here could get a better idea of the goings on.

When the new one show up DO NOT connect up the glow plugs. Slap in the new "BOX' & TSU and head to town. You could if lucky.

I would do the light or multi-meter test on one of the disconnected leads... keeping an eye on the WAIT light and the test set-up to sequence correctly.

At this point leave the test set-up in place and re-connect the seven loose leads back to their plug locations. Run the test again and try to start. If light / meter set-up does not cycle a couple times and then OFF... SHUT IT DOWN My guess you will be OK to GO with a new "BOX" This is the "to be sure exercise"To do or not to do is up to you.

NOT so sure, you got 20 seconds to decide that something is wrong. This is MY safe time to decide that glow plugs will survive at 24 volts before burning open / POOF. If internals of "BOX" decide to go bonkers, a relay sticks, transistor toasts... one can save a set of plugs.

Go with matching TSU and "BOX" to save on more headaches, for new owners, IMO. Could save a buck with the guys help here and research done.

With a known working dash voltmeter, one should pay attention to the cycling-needle dipping when starting. Cold weather note the cycling times. Warmer - summer - hot engine note that too. The wiggle - wag is a tail-tell sign of that HumV "heart beat" I spoke of. Alternator, batteries, glow plugs, etc. If one is a " start and go guy"... you could be in for a out of wallet experience.

Remember to ALWAYS disconnect batteries when making "BOX" connections. 20 second of glow with out a cool off wait is real IF ie. To much computer business going on in the "BOX" IMO. OEM is OK.

Not trying to load anyone up with my diagnostics or delirious writings. Do your thing...this works for me. Guess are free, Wrong guess double free.

"Potato in the tail pipe" CAMO

 

[Retiredwarhorses]

Ok I’ll try the meter thing
Despite the cost of the box I’m very glad you seem so sure that it is in fact bad.

Want box do you have? I’m going to guess it’s a yellow label Narton EESS, I’ve got a stack of bad ones here at the shop that all came out of GP M1123’s. I have brand new Narton S3’s for sale...but I’m running low on them.

 

[M1123 Greg]

Want box do you have? I’m going to guess it’s a yellow label Narton EESS, I’ve got a stack of bad ones here at the shop that all came out of GP M1123’s. I have brand new Narton S3’s for sale...but I’m running low on them.

I’ll get back to you on this I’m at work now, I’ll try to check tomorrow and let you know/picture.

 

[M1123 Greg]

The "old light bulb in the glow plug" trick. That works too.

At this point IMO... Wouldn't waste my time, fooling, wishing, guessing and $$$ with that "BOX"

Sometimes called "Smart Boxes" Cuz it smarts to have to buy another set of plugs, LOL

Time to kill ??? take it out, open it up, and snoop around for smoked parts. For most , nothing to see here... but for piece of mind, the smell of burnt stuff.
Upload some nice pictures inside and out and the part number. It may not fix it, But the guys here could get a better idea of the goings on.

When the new one show up DO NOT connect up the glow plugs. Slap in the new "BOX' & TSU and head to town. You could if lucky.

I would do the light or multi-meter test on one of the disconnected leads... keeping an eye on the WAIT light and the test set-up to sequence correctly.

At this point leave the test set-up in place and re-connect the seven loose leads back to their plug locations. Run the test again and try to start. If light / meter set-up does not cycle a couple times and then OFF... SHUT IT DOWN My guess you will be OK to GO with a new "BOX" This is the "to be sure exercise"To do or not to do is up to you.

NOT so sure, you got 20 seconds to decide that something is wrong. This is MY safe time to decide that glow plugs will survive at 24 volts before burning open / POOF. If internals of "BOX" decide to go bonkers, a relay sticks, transistor toasts... one can save a set of plugs.

Go with matching TSU and "BOX" to save on more headaches, for new owners, IMO. Could save a buck with the guys help here and research done.

With a known working dash voltmeter, one should pay attention to the cycling-needle dipping when starting. Cold weather note the cycling times. Warmer - summer - hot engine note that too. The wiggle - wag is a tail-tell sign of that HumV "heart beat" I spoke of. Alternator, batteries, glow plugs, etc. If one is a " start and go guy"... you could be in for a out of wallet experience.

Remember to ALWAYS disconnect batteries when making "BOX" connections. 20 second of glow with out a cool off wait is real IF ie. To much computer business going on in the "BOX" IMO. OEM is OK.

Not trying to load anyone up with my diagnostics or delirious writings. Do your thing...this works for me. Guess are free, Wrong guess double free.

"Potato in the tail pipe" CAMO

Ya I agree, suck it up and get a new one. I’ll remove it tomorrow and snap some photos

to be absolutely clear cause I’m still new to the lingo, the “Box” in question is the PCU Pretective control unit? Located under dash on driver side (one canon plug there and another canon plug in engine compartment). Is this also the glow plug controller?

also TSU?

 

[Action]

Ya I agree, suck it up and get a new one. I’ll remove it tomorrow and snap some photos

to be absolutely clear cause I’m still new to the lingo, the “Box” in question is the PCU Pretective control unit? Located under dash on driver side (one canon plug there and another canon plug in engine compartment). Is this also the glow plug controller?

also TSU?

The box is a PCB, Protective Control Box.
The newest "smart" versions have an extra plug on passenger side. More and more folks are calling all boxxes smart boxes. That is not correct.
The Glow Plug Controller "GPC" is stuck in the top of the water crossover tube on top of the engine. It has a big plug on top that you squeeze to release. That needs to be paired with the PCB. New PCB's usually come with the correct GPC.