Sudden loss of power while accelerating (4 Viewers)

[Jasonazx]

So I found one of the alternator bolts loose. This would explain the occasional serpentine belt noise I was hearing. It was easily spun by hand. The alternator was definitely able to move. Could this cause my issue?

I also double checked all of the wiring at the front of the engine and everything looked good and routed properly, with the exception of the oil pressure sending unit wire. When I unplugged it the plug easily separated from the wire, so I’ll need to fix that. I also cleaned up some random wiring under the dash from the previous owner, including some old brake controller wiring and other miscellaneous wiring that was laying around and even spliced in to the fuse box at the drivers side kick panel. A yellow box unit has been installed so I traced that wiring as well and inspected the wiring.

I then took it for a spin down and up my usual test route, and the issue did not occur! I’m skeptical anything I did would have fixed it, but crossing my fingers.

Anyone have a part # for the oil pressure sending wire pigtail/plug?

 

[2001LC]

BTW: To fix that one wire, with a few cooper strand cut. Toyota sell the pig tail. You remove the one pin w/wire from the wire housing block. Slip in a new pin w/wire and splice.

I like the

With my home made heat gun attachment to direct heat.

 

[Jasonazx]

BTW: To fix that one wire, with a few cooper strand cut. Toyota sell the pig tail. You remove the one pin w/wire from the wire housing block. Slip in a new pin w/wire and splice.

I like the
View attachment 2974637

With my home made heat gun attachment to direct heat.

I need to do this for both camshaft position sensor and oil pressure sending unit. Does Toyota sell pigtail/plug for both?

 

[jerryb]

oil pressure sender connector is 90980-11363 repair wire with terminal is 82998-12440

cam sensor connector is 90980-11016 repair wire(s) with terminal are 82998-12440 same as above. Both 2.3 terminals

I have those terminals but only for 18-24 gauge wire not sealed.

 

[2001LC]

Trick when wire smaller than butt splice. Place a shrink wrap on smaller wire sheathing, to increase OD. I think is was @flintknapper tough me that one.

One alternator bolt loose of 3, would not allow alternator to shift (03-07 have 3 bolts 98-02 have 2). The other 2 would hold it in. But if wire held by nut or the others plugged in, are loose. That may be another contributor, to your issue.

 

[Jasonazx]

Thanks @2001LC and @jerryb! You guys are the best. Still poking around as I find time. I’ll you all updated.

 

[MongooseGA]

@Jasonazx Did you definitively fix this issue? I'm just now starting to experience the exact issue.

 

[novamarc]

Also would like to know if the issue was ultimately resolved. Having a nightmare of a time trying to diagnose what sounds like the same issue on my 2006 LX470.

 

[MongooseGA]

I'm pretty sure my issue was resolved with a new speed sensor.

 

[Zalie]

I have had this exact problem for almost 10 years! My 1994 has been in to a Land Cruiser shop for weeks and they couldn't figure it out. I will be following this thread. Thank you!

 

[seanz0rz]

This is the exact same issue I am having, and it is getting worse.

Started with just pulling away from a stop. Would only do it once per trip. Now it is starting to do it while I am on the freeway and accelerating to pass. I have no CEL / codes and nothing in the diagnostics in TechStream. It is incredibly intermittent, and is driving me nuts.

Any resolution for this issue?

 

[seanz0rz]

This is the exact same issue I am having, and it is getting worse.

Started with just pulling away from a stop. Would only do it once per trip. Now it is starting to do it while I am on the freeway and accelerating to pass. I have no CEL / codes and nothing in the diagnostics in TechStream. It is incredibly intermittent, and is driving me nuts.

Any resolution for this issue?

I ended up solving this with a replaced throttle body. Replaced the fuel pump and MAF on my journey. So far, so good. I have about 200 miles on the new part. I will be making a bigger trip (400 miles/2 days) this week.

 

[seanz0rz]

I ended up solving this with a replaced throttle body. Replaced the fuel pump and MAF on my journey. So far, so good. I have about 200 miles on the new part. I will be making a bigger trip (400 miles/2 days) this week.

Sadly, not solved. I'm at a loss at this point.

 

[ruggedrudgate]

Sadly, not solved. I'm at a loss at this point.

I think we have the same problem. Happens once, at the same exact stop light after leaving my house and is getting slightly worse but not terrible. Then doesn’t happen again till the car sits for at least 8 hours. How quickly did yours get worse?

 

[seanz0rz]

I think we have the same problem. Happens once, at the same exact stop light after leaving my house and is getting slightly worse but not terrible. Then doesn’t happen again till the car sits for at least 8 hours. How quickly did yours get worse?

I don't even know anyone. Replaced the gas pedal (sensor) and 4 days of commuting and I think it may be happened a tiny bit once maybe, not sure. So far it's been good but not enough time to put some real mileage under it.

 

[HappyCouch]

I recently experienced an unexpected issue with my 2006 LX 470, which is usually very reliable. During a routine left turn, the car suddenly lost power. No response when I pushed on the gas. I managed to safely pull over, although it seemed the engine might have been running rough. After shutting off the engine and restarting it, the car seemed to function normally again, and I was able to drive home without further problems. I took the car to my trusted mechanic, who kept it for a few days. Despite thorough checks, they found no visible problems, no error codes, and they couldn’t replicate the issue. It’s quite puzzling, and it seems I’m not the only one baffled by this. Has anyone identified a definitive solution to this problem?

 

[2001LC]

Number one, movement related sudden loss of power. Is a short.
Battery connecting or ground, are most common.

 

[seanz0rz]

I don't even know anyone. Replaced the gas pedal (sensor) and 4 days of commuting and I think it may be happened a tiny bit once maybe, not sure. So far it's been good but not enough time to put some real mileage under it.

For my issue, it continues, sometimes severely. I am now concentrating on the transmission. I believe there is a shifting issue and the ecm is idling the throttle while the trans tries to figure out what it is doing. Still no CEL, which is extremely frustrating.

 

[Landcresha]

Hello all - I’m trying to resolve an issue we’ve been having every time we drive the cruiser. I suddenly lose power most commonly when accelerating up hill. The engine is still running but there’s no throttle response for a couple seconds, then it comes abruptly back online. I receive no check engine lights while driving or codes when connected to techstream or when performing techstream health check.

Here’s a video I took while driving to show what’s going on:

Vehicle details:
2006 LX 470
~203,000 miles

Major maintenance and repairs performed or issues reported (excluding the more basic maintenance items):

90k - previous owner had timing belt and water pump service done by toyota.

104,000 miles - previous owner reported to Toyota that vehicle would stall out on highway through high elevation passes and smelled like fuel. Toyotas answer was to replace spark plugs.

128,000 miles - previous owner had cooling system flushed and new radiator hoses installed by toyota.

144,000- previous owner took to Toyota as vehicle would not start. Reported that they filled up at a remote gas station. Toyota replaced fuel pump, filter and pump relay. Siphoned gas from tank and added fuel cleaner.

156,000 - spark plugs replaced again at Toyota. No other notes.

173760 miles- previous owner reported to Toyota that vehicle will randomly lose power. Service notes from toyota: drove vehicle several times and could not duplicate issue or make any repair recommendations at this time.

177519 miles - previous owner reported to Toyota that vehicle was getting hot (over 200 degrees when driving) Toyota replaced radiator due to poor flow.

180,000 miles- timing belt, water pump and throttle body replaced at Toyota by previous owner.

183,000 miles- previous owner took truck back to Toyota stating cel and vsc lights on. Toyota noted code p2714 for transmission pressure control solenoid “d” stuck off. Drained transmission and found significant amount of metal in fluid. Toyota replaced transmission.

194,000- I purchased from previous owner listed on mud. Issue of random loss of power occurred within first 1,000 miles of my ownership.

203,000 miles - over the past few weeks I have replaced the fuel pump with a denso unit, fuel filter from toyota, pcv valve and hose, coolant and transmission flush at toyota, new steering rack, all new power steering hoses, front wheel bearings and races, new oem cv axles, all new brakes and brake fluid flush. I also swapped in an accelerator pedal position sensor I purchased from an eBay seller reporting that they refurbish oem sensors to see if that was causing the problem. It’s still happening.

I’m at my wits end with this issue. Great truck otherwise and was taken in for service at either Lexus or Toyota it’s whole life. No rust, no leaks - super clean Arizona and Colorado truck.

I did read on a tundra forum mentioning similar issues. They replaced the knock sensors and repaired some wiring and the problem went away. I’m thinking my next move is to remove manifold and have a peak underneath to see if anything’s chewed up. If wiring looks good then replace knock sensors, have the injectors cleaned and possibly replace the air induction pump. Great time to replace injector o rings, coolant pipe gaskets and starter while I’m in there.

Appreciate any ideas of what this problem could be! @2001LC interested to see if you may have any insight.

Thanks!

Edited to add: I should mention that the loss of power issue during my ownership has been off and on leading up to this past month. I could go weeks without the problem occurring. Over this past month or so I experience the problem every time I drive it.

Did you figure out the problem?

 

[seanz0rz]

Did you figure out the problem?

No. Still working through troubleshooting. Drove it 25 miles each way to work and back, recording with tech stream and it did not happen today. Trans looks OK, now looking into the ECU and associated sensors and cables.

My thread: RPM drop to idle during downshift, loss of power when passing, extremely intermittent - https://forum.ih8mud.com/threads/rpm-drop-to-idle-during-downshift-loss-of-power-when-passing-extremely-intermittent.1345622/