BJ73 - Low battery?

[Lantec]

Whenever I start up the car after its been sitting overnight, the battery gauge will show as nothing until I drive for a bit, then it'll shoot up to the normal position..

The pyro tends to jump up and down a bit too during that time (for like 15 seconds or so before settling down), my radio will also turn off for a second before coming back. Everything works fine but it didn't do that before.

Is there something wrong with my batteries? It's a JDM 24V BJ73

 

[Greg_B]

What happens if you leave the truck on high idle for a minute and not drive it. Does the charging system kick in after a minute or so?

gb

 

[Lantec]

Yeah I think so. I haven't tested this specifically yet. I just know after a while, it'll shoot up by itself, this can be pretty quick (within 2 minutes) or can take up to several minutes.

 

[Greg_B]

My BJ74 has a delay that is noticable on the voltage gauge. I use it during the cold months as a cold start indicator to start driving. I've never timed it, however it seems about a minute...or less. I know others have commented the same.

hth's

gb

 

[M John Galt]

My BJ74 has a delay that is noticable on the voltage gauge. gb

yes, that's from the glowscreen combustion air heater

 

[Lantec]

My BJ74 has a delay that is noticable on the voltage gauge. I use it during the cold months as a cold start indicator to start driving. I've never timed it, however it seems about a minute...or less. I know others have commented the same.

hth's

gb

Is it a pretty good indicator for when to start driving? I use the oil pressure to get to half before i start driving but I can be driving for almost 3-5km before the voltage meter goes up to normal.

 

[Greg_B]

yes, that's from the glowscreen combustion air heater

Hi John.

The temps we are talking about right now in the Lower Mainland are not anywhere near where the glowscreen system activates. You do raise an interesting point...to check if his system has malfunctioned and is activating. That would be a huge draw on the system over the times indicated.

Lantec, yours sounds slow. Most I have seen are within a minute or less. If I start and go I can't get out to the main road from my place without it having kicked in (a very short distance).

Run a voltmeter on it from start to when it kicks in, record the voltage and time taken. Check for voltage at the intake screen too, just to eliminate.

gb

 

[brownbear]

Is it a pretty good indicator for when to start driving? I use the oil pressure to get to half before i start driving but I can be driving for almost 3-5km before the voltage meter goes up to normal.

oil pressure is not enough of an indication it's ready to drive IMOP.

It's more by ear than anything. Listen to the engine. A warm engine is smooth idling. A cold engine knocks and detonates. If you let it idle for 30 seconds to 2 minutes(depends on temp) you will hear it smooth out a bit. That's when it is time to go. Less stress on the crank/head/bearings....etc.

Coolant temp is not what I am talking about. I am referring to head temps when they are starting to be consistent across the head.

Oil pressure is important, but not the indicator to start driving.

 

[brownbear]

for voltage troubleshooting, sit at your battery with a multimeter when it starts, see what the voltage is as it idles. See if it all of a sudden jumps up to charging temp. It could be an indicator fault. Maybe the regulator needs to warm up to come online. Is it worse in the cold...?

 

[Lantec]

for voltage troubleshooting, sit at your battery with a multimeter when it starts, see what the voltage is as it idles. See if it all of a sudden jumps up to charging temp. It could be an indicator fault. Maybe the regulator needs to warm up to come online. Is it worse in the cold...?

Yeah, it seems like that anyway. It's done that during the summer on the cold start but usually jumps up by the time I back out of the garage but now, it goes for a bit.

ATEB set my idle pretty high after they installed the turbo, it won't dip under 850rpm and when AC is on, it'll go up to 1,200 or so.

Should I just let it idle with AC until the engine smooths out?

Should I run the voltmeter on the first or second battery?

 

[Greg_B]

This is a BJ-73 so probably has glowplugs instead of glowscreen, but I suspect the timer is the same. It's activated by a temperature sensor in the housing above the thermostat. If this sensor is defective, or unplugged then the timer is activated on start.

Yes, I use the time it takes for the voltage to come up to normal as an indication of good warm-up interval.

Ahh, yes. Brain fart...will be a 3B with plugs. Which could well mean differing temp cycles. Not anywhere near a FSM to check. Lantec...check your glow cycle. The superglow simply may be doing it's thing longer then spec. It is all outlined re timer/voltage drop off.

hth's

gb

 

[brownbear]

Should I just let it idle with AC until the engine smooths out?

Should I run the voltmeter on the first or second battery?

I used to set the hand throttle around 1k to warm up. So that it would not bang too much.

It's not hard to turn your warm idle down a bit. 850 seems high. 6-700 might sound nicer. When warming up you don't want to race the engine. Just enough throttle to let not bang around.

Check your voltage on the second battery where the main wires hook up to it. Negative probe on the body or neg post.

If you have glowplugs instead of a glow screen the afterglow might be kicked in for bit while it idles. This is part of the glowplug timer that puts partial glow on the plugs when idling for a bit to smooth it out. That would hold the voltage down one or two volts. But not 0 volts.

Is it at 0 volts or 24(12) when you first start? then it goes after a min or two to 28(14)...?

 

[Lantec]

I used to set the hand throttle around 1k to warm up. So that it would not bang too much.

It's not hard to turn your warm idle down a bit. 850 seems high. 6-700 might sound nicer. When warming up you don't want to race the engine. Just enough throttle to let not bang around.

Check your voltage on the second battery where the main wires hook up to it. Negative probe on the body or neg post.

If you have glowplugs instead of a glow screen the afterglow might be kicked in for bit while it idles. This is part of the glowplug timer that puts partial glow on the plugs when idling for a bit to smooth it out. That would hold the voltage down one or two volts. But not 0 volts.

Is it at 0 volts or 24(12) when you first start? then it goes after a min or two to 28(14)...?

Well I used to be able to turn down the idle, but now, I can crank it all the way to the left until it locks but it'll stay at 850. I can increase it though, but 850 seems to be the minimum.

It stays at 0 volts (needle all the way down) until after a bit, then it'll shoot up to the normal position, 28V I assume?

The battery light doesn't turn on though and everything seems to work like normal, except now, the radio will turn off momentarily (1 second) after I start the engine.

 

[Lantec]

Ok, definately some problems.

Today, when I went to start the car, it had trouble cranking out, the lights were dim, clock was reset and even my radio stopped working (due to low voltage?)

I couldn't start the truck with the brake pedal pressed, i assume the lights were making too much of a draw on the battery, I let go and it cranked over. I drove around and got the batteries charged up and the next time I started it up, it seemed ok. But I think maybe the battery is messed

 

[Greg_B]

1st, check all battery connections. Get a terminal connection cleaner. Take them all apart, ensure clean...but back together. Check your ground connections (block, chassis). If that does nothing then take the batteries to a place which will load test them. If one battery is on it's way out replace both so you have a matching set.

Do you have a 3B/13B FSM? Lots of troubelshooting in the 1st section via flow charts, for specific issues.

gb

 

[Lantec]

1st, check all battery connections. Get a terminal connection cleaner. Take them all apart, ensure clean...but back together. Check your ground connections (block, chassis). If that does nothing then take the batteries to a place which will load test them. If one battery is on it's way out replace both so you have a matching set.

Do you have a 3B/13B FSM? Lots of troubelshooting in the 1st section via flow charts, for specific issues.

gb

I don't have a FSM

It's not that dangerous to take out a battery rightr? I'm really frightened when it comes to car batteries.... I sqirm even when I see sparks go off when jump starting a car