Worth checking... Unbolt, sand with sandpaper to get good metal to metal contact, and then restart... It sounds like you have done a lot so far so it's worth a shot.
How come I have to blip the throttle to get my 3b to run when cold?
- Thread starter Reinhardtius
- Start date
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The next steps would be checking the whole super glow system for proper operation... Which is less fun.
- Thread starter
- #63
I thoroughly cleaned the engine ground wire to the engine, all battery terminals, and the engine thread where the wire connects using a dremmel. I also tested the resistance of the engine ground wire and it was .1 ohm (good and normal).
I also checked the air cleaner. It’s fine.
Same starting trouble.
With the engine running, I still get 32-34V from driver side battery positive to glow plug head. I also get 30-31V from battery positive to the grounds on the two relays tucked into the driver side fender (by the battery tray). On the other side (passenger), there are some other grounds along the fender, and when I run the multimeter from the passenger side battery positive to them, they read 24-26 volts.
What do I do next? I’m not jazzed about going to any local mechanics if I still don’t have a clue what’s causing the cold start issues.
I also checked the air cleaner. It’s fine.
Same starting trouble.
With the engine running, I still get 32-34V from driver side battery positive to glow plug head. I also get 30-31V from battery positive to the grounds on the two relays tucked into the driver side fender (by the battery tray). On the other side (passenger), there are some other grounds along the fender, and when I run the multimeter from the passenger side battery positive to them, they read 24-26 volts.
What do I do next? I’m not jazzed about going to any local mechanics if I still don’t have a clue what’s causing the cold start issues.
bcsteel
SILVER Star
Have you looked at the wires from your ignition? Fuses?
Did you clean the ground back to the side battery?
- Thread starter
- #66
If you mean the ground from the engine to the battery, then yes. That’s the ground wire I describe in my last post.
Not sure if you did this, but clean every ground you can find, not just the main one. Also, not sure youve done this either, but check the voltage at the bus bar/glow plug just as you turn the key, this should show the initial high voltage, followed by the drop. Get the manual and work through the diagnostic part about the relays.
@Reinhardtius I was meaning the ground wire from the frame to the low side Neg terminal of the battery. If you don't have one, you might think of adding it as I believe most rigs had one... There should be one as well as a cable from the engine block to the low battery. On my rig, I ground my block to the frame on both sides (one is the starter ground to frame and the other goes from block to frame). I also have military terminals so I have another ground from the battery tray mount to the low neg terminal too.
Grounds are super important I have found... Almost melted one of my batteries because of bad grounds...
Grounds are super important I have found... Almost melted one of my batteries because of bad grounds...
- Thread starter
- #69
Sorry, yes! I cleaned the whole wire from frame to negative, too. It looked great. Bear in mind that I have a HELLA battery disconnect installed, but all those connections were cleaned and looked great.
See photo of wire removed after cleaning:
I just ordered some alligator clips for the multimeter so I can hook up the meter and watch it while I start the truck, but I need some help to identify exactly what voltages I should be looking for at all stages of the starting procedure, and at all locations. I’m sorry to be so damn clueless- I don’t even know where my dear glow plug relay is hidden!
In other news, I cleaned the interior to make me feel better about how nice the truck is otherwise.
- Thread starter
- #70
@samewise ok, thank you... What’s the initial high voltage I am looking for, and what should it drop to?
John in Utah
SILVER Star
I’ll try to jump in here.
Should be 24V to the plugs and then drop to 14V based on the threads I’ve found. The resistance of the plugs is lower than a straight 24V plug would be, hence the “super glow”
Super Glow - explained
Which plugs should I be running - B, 2B, 3B, H and 2H diesels
I’d try connecting a jumper straight from your battery positive to the busbar for ~10 seconds and see if that helps the starting issue, then trace back your system from there.
10 seconds may be a lot... I'd start with 3-4 seconds. The reason is that with a jumper you will be hitting a 14v plug with full 24v for 10 seconds. Even when you connect the circuit on a non-superglow 24v rig, the plugs only get hit with 21-22v due to voltage drop... This is why a non-superglow plug is 21.5v rated.
- Thread starter
- #73
Thanks @John in Utah. That thread is an unusually comprehensive description of the system, and indeed super helpful.
I'll try the jumper out.
@BreckenridgeCruiser.
Would I still get 24V to that bus bar if I am running a jumper from one positive terminal to the bus bar, or would it only be 12V?
Also, I bought 15-40 dino oil (Rotella T4) and a brand new OE toyota filter (90915-YZZD3) in an attempt to rid the possibility that this issue is related to the oil filter being defective (i.e. faulty anti-drain back feature), or synthetic oil not being ideal. These, I will admit, are far flung possible hypotheses, but I have to rule them out.
I am also considering ordering a new fuel filter and air filter, even though the truck runs great once warm.
But first, I will replace oil and filter, and try the jumper.
I'll try the jumper out.
@BreckenridgeCruiser.
Would I still get 24V to that bus bar if I am running a jumper from one positive terminal to the bus bar, or would it only be 12V?
Also, I bought 15-40 dino oil (Rotella T4) and a brand new OE toyota filter (90915-YZZD3) in an attempt to rid the possibility that this issue is related to the oil filter being defective (i.e. faulty anti-drain back feature), or synthetic oil not being ideal. These, I will admit, are far flung possible hypotheses, but I have to rule them out.
I am also considering ordering a new fuel filter and air filter, even though the truck runs great once warm.
But first, I will replace oil and filter, and try the jumper.
Did you mention that you were using synthetic before? That might take longer to build pressure...
If you jumper the low side positive then you will get 12v. Not a good idea to yep 12v for any appreciable amount of time as these systems hate imbalanced batteries, but for this it should be fine... If jumping 12v I'd hit it for 20 or more seconds...
If you jumper the low side positive then you will get 12v. Not a good idea to yep 12v for any appreciable amount of time as these systems hate imbalanced batteries, but for this it should be fine... If jumping 12v I'd hit it for 20 or more seconds...
- Thread starter
- #75
Correct, was running T6 Rotella (full synthetic). I took it out, and replaced with T4 (non-synthetic) Rotella. I also put a brand new OE Toyota oil filter on (90915-YZZD3). The start is the same. Hard. It's gotta be the glow system!
OK, I was not sure about what low side positive meant until I had the following interaction on Friday:
While at the parts store getting stuff for my daily driver I ran into a person who was quite interested in the truck sitting outside. We got to talking and I explained to him that it's a wonderful ride other than cold start. I asked him about his knowledge of 24V, to which he replied, "it's not that much different from 12". He drew the batteries and wiring as a diagram on a sheet of paper, and showed me that I may have been testing my voltages as mentioned here How come I have to blip the throttle to get my 3b to run when cold?. Basically, I think that I have been checking the voltage from the low side (driver side), instead of from passenger side, where the battery grounds to the frame. Doh!
He said he could troubleshoot it for me, and based on his grasp of my problem, I think he can help. He has a hunch that the truck is hard to start because it's not getting glow. If that is the case, then I may need to get my hands on new glow plug relays, but I don't want to fry replacements, so knowing what can fry them would be helpful.
According to this diagram, the Sub glow plug relay is located in the driver side fender area. See diagram below. (1) Does anyone know where the Main glow plug relay is located? And again, (2) if you know what can fry these relays, let me know so I can check the system to avoid that from happening if me and the mechanic replace them.
Yeah... Understanding the terminology is as bad as learning the system
Ground -> (-) Low side Battery (+) -> (-) High side battery (+) -> vehicle 24v
Ground -> (-) Low side Battery (+) -> (-) High side battery (+) -> vehicle 24v
I am not sure your relays are the issue.. best way to test is to put your volt meter POS on the bus bar and the NEG on the block. If you have someone cycle the glow and you see 24ishV and then after a few seconds you see 12ishV then the relays are working. That also let's you know that the computer is cycling them correctly. If the voltages are odd, or the timing seems odd then you might have high voltage drop in the system, or something in the sensor (resistance) system not working correctly.
Can you get access to the glow controller? What is the P/N? I might have a spare you could try and see if you get the same result. May be eaiser that trying to diagnose each circuit of the computer if it ends up being a possible culprit.
Can you get access to the glow controller? What is the P/N? I might have a spare you could try and see if you get the same result. May be eaiser that trying to diagnose each circuit of the computer if it ends up being a possible culprit.
- Thread starter
- #78
Thanks for the kind offer. I may take you up on that.
I’m having a mechanic look it over on Monday. I haven’t had time to self-diagnose.
Part numbers for glow relays are:
28610-54180 24V SUB
28610-57090 24V MAIN
I’m gonna print a wiring diagram of the glow system for him and point out where stuff is to save him confusion.
Can anyone explain where the controllers, fusible links, and relays are located? Maybe 75 series folks...? @coldtaco
Fusible links are near the positive battery cable at the battery end
After watching your video, I dont think there is anything wrong except your starting procedure. It doesn't hurt the starter to let it run a second after it starts. Try turning the idle up to 1000+, that's what its for.
