Update: Potential Culprit Found? —> 2000 LC Dies, Battery, Check Engine, AT Oil Temp Lights (1 Viewer)

[TheBestCow]

Update: potential culprit issue identified. Thoughts? (Direct link to reply post with photos)

Went on a disaster of a hike this morning with my wife and kids.

On the way home, coming to an intersection and slowing down to turn, LC completely loses power. Turns off, loses power steering, etc. The battery, check engine, and automatic transmission oil temp light comes on. (Almost like they do when you put the key in but don't have the engine running.)

I'm able to put it into park, and restart. A few miles down the road, same thing. We were pretty low on gas, so I was able to limp it to a station and put 6 gallons in it, enough to get it up between 1/4 and 1/2. Checked fluids - I've got the AT dipstick - and nothing low. Checked under LC, no leaks.

Plugged in my Ultragauge. Battery voltage is fine. I can't find an AT oil temp display on the Ultragauge, so can't confirm that, but I can confirm based on the dipstick the oil is above the hot line.

Also, no engine codes coming up on the Ultragauge.

It seemed to happen more if I were letting off of the throttle, but I can't confirm that it happened ONLY when doing that. I was trying not to get hit in traffic, turning on my caution lights, etc.

It almost felt like it was falling out of gear or giving me the same "thunk" that I've had going from Park to Drive, or Park to Reverse, or Reverse to Drive, or Drive to Reverse. I've read about those on the forum and figured it was normal or maybe the front diff bushings need replacing. But when all of the power would drop, it almost gave a similar sound. Maybe there's something causing the transmission to think it needs to disengage?

Temperature outside was about 85 degrees. Not doing any major incline or decline. Mostly on flat or mostly flat ground.

Right before we got home on one of the back roads, I put it in neutral to coast down a hill to see if disengaging the transmission in that way would make a difference; it died again. And this time when I went to restart, it didn't want to. Turned over, but didn't want to start. Turned off, took key out, waited a few seconds, and tried again and it was able to start up and get back to my house and garage. Pulled EFI fuse and it looks okay.

Oh, and mileage: 243,xxx

Thoughts?

Could it be:

• fuel pump - lack of fuel causing engine to die?
• EFI fuse - not pumping fuel correctly?
• fuse box - sounds similar to this 1999 UZJ100 Intermittently Drops Dead
• transmission failure
• alternator failure or loose ground - but if that were the case, wouldn't the multiple re-starts eventually drain the battery?

I don't believe it is:

• APPS/TPS - this isn't having 25% power or being in limp mode, this is completely losing all power and the LC turning 'off' essentially

Appreciate any guidance or things to check next.

 

[SoCal_80]

Does it die or stumble when you brake and or when you turn on the headlights? I had a similar odd situation in my old 80 series and it was a bad cell in the battery. voltage appeared to be fine until a load was placed on it then it would drop under 10v and the engine would die.

 

[TheBestCow]

Does it die or stumble when you brake and or when you turn on the headlights? I had a similar odd situation in my old 80 series and it was a bad cell in the battery. voltage appeared to be fine until a load was placed on it then it would drop under 10v and the engine would die.

Definitely not headlights. I can't recall if in every situation I was actively braking or just letting off throttle.

However, you did make me run back out and plug the Ultagauge back in. Now I'm not an expert at UG, or LCs for that matter, so I'm using the "UG Volt" setting for one of the screens. My understanding is this is what Ultagauge is gauging the voltage to be...?

Here are some results from idling in my garage:

• UG Volt shows ~12.28 with key in on position, but not cranked (so lights on dash, etc.)
• jumps up to over 14 when running
• When I turned both front and rear AC on, the radio, headlights, and the aftermarket fog lights it started to drop. Not linear, but two lower readings and then slightly higher... two lower readings then slightly higher... for example: 11.65, 11.62, 11.64, 11.55, 11.53, 11.57, 11.45, 11.49... this was in park, idling. When I rev the engine it goes above 12. Could dropping down to the 11s be an indicator of a battery problem?
• Battery is new as of 3/20, I believe, says "03/20" on the side. Installed by previous owner, it's the Gold version of whatever Advance Auto Parts sells.

I should note I don't have a multimeter so I'm relying on the Ultragauge right now

Also, in my experience when a battery fails, you can't restart on your own -- you can jump it off and get it to where you need to go. This seems different -- I am able to restart, then the vehicle dies, then I restart, then vehicle dies. This happened ... I dunno, 6-7 times as we limped home.

 

[TheBestCow]

I just remembered I have a Viking (Harbor Freight) battery charger/maintainer. Popped it on. Charger has 5 bars of charging level and it was showing around 12.5-12.7 as a starting charge (and only one bar blinking, meaning it needs a lot of charge). Going to leave it charging until the display turns green. Currently at 13.1V and the 3rd charge bar is blinking.

(Now that I'm read more and digested my beer, I think this means it was going through the charging cycle not how much charge was needed. It went all the way up to 14.4-14.5 and then pulled down, started bouncing around 13.3-13.5, etc. When I pulled it off tonight (and then plugged back in) it was up to a 'starting' charge of 13.1).

Does this give any more hints? Could it be alternator? I’m thinking if I get the battery full charged and go drive for a bit, keep the UltraGauge plugged in to monitor voltage, come back and see if we are down on charge? I haven't driven much in the last two weeks aside from pulling it out of the garage to get my lawn mower out. Not sure if that's relevant, but trying to provide details.

 

[bobcatag2006]

My truck died while driving through the neighborhood on Sunday. Wouldn’t restart and it was sluggish about 1/4 mile before it just limped dead. I could jump it and once got the battery and truck running maybe made it a block and it died.

Buddy towed me and we jumped again and disconnected the positive terminal on my battery and the engine died immediately. That’s the alternator. So we replaced that and a new battery (it was almost 3yrs old) and it’s running fine since then.

 

[TheBestCow]

My truck died while driving through the neighborhood on Sunday. Wouldn’t restart and it was sluggish about 1/4 mile before it just limped dead. I could jump it and once got the battery and truck running maybe made it a block and it died.

Buddy towed me and we jumped again and disconnected the positive terminal on my battery and the engine died immediately. That’s the alternator. So we replaced that and a new battery (it was almost 3yrs old) and it’s running fine since then.

So you'd recommend I start it up tomorrow, and while running disconnect the cable to the positive terminal?

 

[bobcatag2006]

So you'd recommend I start it up tomorrow, and while running disconnect the cable to the positive terminal?

Yes. Let it run a moment before you do. If it runs after disconnecting then the alternator is probably ok. If it dies after pulling the cable then it’s the alternator

 

[JunkCrzr89]

• UG Volt shows ~12.28 with key in on position, but not cranked (so lights on dash, etc.)
• jumps up to over 14 when running
• When I turned both front and rear AC on, the radio, headlights, and the aftermarket fog lights it started to drop. Not linear, but two lower readings and then slightly higher... two lower readings then slightly higher... for example: 11.65, 11.62, 11.64, 11.55, 11.53, 11.57, 11.45, 11.49... this was in park, idling. When I rev the engine it goes above 12. Could dropping down to the 11s be an indicator of a battery problem?
• Battery is new as of 3/20, I believe, says "03/20" on the side. Installed by previous owner, it's the Gold version of whatever Advance Auto Parts sells.

It went all the way up to 14.4-14.5 and then pulled down, started bouncing around 13.3-13.5, etc. When I pulled it off tonight (and then plugged back in) it was up to a 'starting' charge of 13.1).

Sounds to me like the voltage regulator in the alternator is bad. Battery sounds like it’s fine.

 

[TheBestCow]

Yes. Let it run a moment before you do. If it runs after disconnecting then the alternator is probably ok. If it dies after pulling the cable then it’s the alternator

A quick Google search is saying this can be a bad idea as the battery acts as kind of a suppressor for irregular voltage so things like ECUs might be at risk? Better to try getting a multimeter and test? I'd like to test it while running, the initial numbers with the AC, radio, lights on dropping down into the 11s is what caught my attention as to maybe the battery wasn't getting a charge from the alternator. But then I'm not sure how we were able to stop/recrank from dead 8+ times on the way home if that were the case.

Sounds to me like the voltage regulator in the alternator is bad. Battery sounds like it’s fine.

Since you quoted two of my posts, just want to clarify -- the charger was running through it's charge cycle in the second post where it was bouncing around 13.3-13.5.

So assuming that's not relevant, would you consider the voltage regulator just on the first post?

 

[JunkCrzr89]

A quick Google search is saying this can be a bad idea as the battery acts as kind of a suppressor for irregular voltage so things like ECUs might be at risk? Better to try getting a multimeter and test? I'd like to test it while running, the initial numbers with the AC, radio, lights on dropping down into the 11s is what caught my attention as to maybe the battery wasn't getting a charge from the alternator. But then I'm not sure how we were able to stop/recrank from dead 8+ times on the way home if that were the case.

Since you quoted two of my posts, just want to clarify -- the charger was running through it's charge cycle in the second post where it was bouncing around 13.3-13.5.

So assuming that's not relevant, would you consider the voltage regulator just on the first post?

The first post of yours that I quoted was what I was referencing as indicating bad voltage regulator in alternator. Second post of yours that I quoted (battery charger post) indicates battery is fine.

 

[TheBestCow]

The first post of yours that I quoted was what I was referencing as indicating bad voltage regulator in alternator. Second post of yours that I quoted (battery charger post) indicates battery is fine.

Ah, I see. Should I pop over to the parts store tomorrow to have them test the alternator?

Either way, at 243,xxx and unknown if this alternator has ever been replaced... would it be better to just replace the whole unit? Or is the regulator a separate part? And obviously an alternator is much more expensive than what I'm seeing the regulator for on Partsouq.

 

[bobcatag2006]

I don’t have a voltage reader or whatever. It’s just a quick test for the alternator in a pinch.

 

[JunkCrzr89]

Ah, I see. Should I pop over to the parts store tomorrow to have them test the alternator?

Either way, at 243,xxx and unknown if this alternator has ever been replaced... would it be better to just replace the whole unit? Or is the regulator a separate part? And obviously an alternator is much more expensive than what I'm seeing the regulator for on Partsouq.

Having it tested is a good idea. Pretty quick for any chain parts store to test battery + alternator.

Regarding whether to rebuild or replace, that really depends on your situation. If this is your daily driver and you don’t have another vehicle, then you need to buy another alternator to minimize downtime. If the cruiser can sit for a few days, then you can rebuild your alternator or have a reputable shop rebuild it for you.

FYI, you can buy a rebuilt Denso (OEM manufacturer for Toyota) for $134 + shipping, which, after you send back yours as a core, totals $100.

 

[fjcruising]

I mean... it could be the battery/alternator but I’m leaning more towards fuel pump issue before you start throwing parts at it. The lights on the dash light up when the engine dies as if you just turned your key to on without starting the engine - that tells me it has battery - and if the battery light isn’t on while you are driving, the alternator is likely working (probably old but working).

 

[JunkCrzr89]

I mean... it could be the battery/alternator but I’m leaning more towards fuel pump issue before you start throwing parts at it. The lights on the dash light up when the engine dies as if you just turned your key to on without starting the engine - that tells me it has battery - and if the battery light isn’t on while you are driving, the alternator is likely working (probably old but working).

Dropping below 12 volts with engine running. I agree it still could be fuel pump, but alternator isn’t working properly as is.

 

[TheBestCow]

I mean... it could be the battery/alternator but I’m leaning more towards fuel pump issue before you start throwing parts at it. The lights on the dash light up when the engine dies as if you just turned your key to on without starting the engine - that tells me it has battery - and if the battery light isn’t on while you are driving, the alternator is likely working (probably old but working).

What are some steps I should take to test for that? I figure parts store can handle testing alternator for that theory. What’s the rest for fuel pump?

 

[TheBestCow]

Got battery fully charged according to my charger - turned green, went into maintenance mode.

Just did a few laps around the neighborhood. With radio and ACs off, stayed around 14 (I think bounced down to 13.7-13.8 at one point). Turned radio and ACs on and dropped down at one point to 13.16 was the lowest when coming off of the throttle; then went back to >13.6. About to head over to Advance to have them test the alternator and to buy some backup fuses -- when looking at the EFI fuse, noticed the spares normally kept under the fuse box lid are gone as is the tool. So need replacements either way.

 

[fjcruising]

What are some steps I should take to test for that? I figure parts store can handle testing alternator for that theory. What’s the rest for fuel pump?

I would eliminate the alternator/batter being an issue. If the alternator is dying while in transit, the battery should still carry some load so the car would not shut down unless the battery was bad too: I think a bad battery/alternator combo would be unlikely. (i went mudding about 12 years ago and buried an FJ in the mud, alternator was caked full of mud and immediately stopped working, battery light went up on the dash, battery held up to get me back home, however at the end it was struggling, wanting to stall but never did) - that's why i think its not your alternator/battery, especially if your battery is allowing for you to start back up.

On the LC, i did replace my alternator because it started making a grinding noise signaling it was going to go out, and it was charging less than 14v, but was still holding up.

replacing the fuel pump actually is easier/cheaper than an alternator - a lot of labor for the alternator. I would also replace the fuel filter (also an easy DIY) just in case its clogged and with the possibility its never been done.

 

[TheBestCow]

Alternator tested fine at Advance. Said it was putting out 13.7-13.8. Now we didn't test it for a long time, but he had it hooked up, I cranked it, idled for a while, and then revved to 2k RPM.

Is there anything to do to test the fuel pump?

Looked up a pump on RockAuto - found this Denso that has the strainer as well- says:

Fuel Pump Replacement: Do it right the first time!

Prior to Replacing Pump, check:

• Fuel Pump Fuse(s)
• Fuel Pump Relay
• Voltage at the Pump - test for bad wiring
• Voltage drop test - corroded connector, bad wiring
• Fuel System Pressure - test for pump pressure being outside accepted range

When Replacing Pump, also:

• Replace the Fuel Filter
• Replace the Fuel Strainer
• Clean / Flush Tank
• Refill with fresh, uncontaminated fue

I've got a multimeter coming tomorrow via Amazon if anyone can tell me how to test the fuse, relay, voltage at pump, etc. Learning as we go here.

Found this fuel pump replacement thread -- someone mentions to replace the o-ring as well -- the image for the Denso shows what looks like an o-ring, is that the one mentioned? Looks pretty simple? Remove seats, pull carpet back, open access panel, disconnect and pull out old pump, put in and reconnect new pump?

 

[fjcruising]

Alternator tested fine at Advance. Said it was putting out 13.7-13.8. Now we didn't test it for a long time, but he had it hooked up, I cranked it, idled for a while, and then revved to 2k RPM.

Is there anything to do to test the fuel pump?

Looked up a pump on RockAuto - found this Denso that has the strainer as well- says:

I've got a multimeter coming tomorrow via Amazon if anyone can tell me how to test the fuse, relay, voltage at pump, etc. Learning as we go here.

Found this fuel pump replacement thread -- someone mentions to replace the o-ring as well -- the image for the Denso shows what looks like an o-ring, is that the one mentioned? Looks pretty simple? Remove seats, pull carpet back, open access panel, disconnect and pull out old pump, put in and reconnect new pump?

I am out on the testing procedures but hoping bumping the thread can help.