Sudden loss of power while accelerating (4 Viewers)

[2001LC]

I'd look very close at the camshaft sensor and wires, in this case (P0011). It's the best clue you have. Pull codes while driving when it happens. What sometimes happens, it's a-one-off and only pending. Then self clears. So catch by scanning right away, while still driving.

In tech stream, watch engine date. Hit record lower right hand corner. It only records for short duration. It's best to have second person to drive, as you watch.

If you get up to Denver stop in. PM and will share contact info. link PM to this thread.

 

[Jasonazx]

I'd look very close at the camshaft sensor and wires, in this case (P0011). It's the best clue you have. Pull codes while driving when it happens. What sometimes happens is I'ts a one off and only pending. Then self clears. So catch by scanning right away, while still driving.

In tech stream, watch engine date. Hit record lower right hand corner. It only records for short duration. It's best to have second person to drive, as you watch.

If you get up to Denver stop in. PM and will share contact info. link PM to this thread.

Thank you! Will try that, and if I can’t figure this out I may take you up on that offer to bring it up.

 

[YezusLX]

This is just my two cents: I had a customer at my dealership experience a similar issue with a Corolla. This only occurred upon acceleration if my memory is correct. Two things after about a month of back and forth between our shop and his home ended up being the root of this issue. I have not seen it mentioned yet. In Georgia, we have an issue with rodents. Everything from rats to field mice, and especially squirrels. Upon a momentum shift (say a gear change) and vehicle weight would come forward and then backward we discovered the wires to the coil packs and TPS were touching the valve cover/manifold causing an arc. We then followed this into the main harness to the ECU and found a nice little nest made inside the dash with several baby field mice in it made from Toyota wiring insulation. Not sure if this would be of assistance but I remembered this acceleration loss issue being the cause and return of that vehicle several times until we had discovered the rodent damage with no known CEL or DTC codes. The solution ended up being the main ECU harness and three coil packs and the problem ceased. Hopefully, this helps.

 

[Jasonazx]

This is just my two cents: I had a customer at my dealership experience a similar issue with a Corolla. This only occurred upon acceleration if my memory is correct. Two things after about a month of back and forth between our shop and his home ended up being the root of this issue. I have not seen it mentioned yet. In Georgia, we have an issue with rodents. Everything from rats to field mice, and especially squirrels. Upon a momentum shift (say a gear change) and vehicle weight would come forward and then backward we discovered the wires to the coil packs and TPS were touching the valve cover/manifold causing an arc. We then followed this into the main harness to the ECU and found a nice little nest made inside the dash with several baby field mice in it made from Toyota wiring insulation. Not sure if this would be of assistance but I remembered this acceleration loss issue being the cause and return of that vehicle several times until we had discovered the rodent damage with no known CEL or DTC codes. The solution ended up being the main ECU harness and three coil packs and the problem ceased. Hopefully, this helps.

This definitely has come to mind, and one of the reasons I’m inclined to pull the manifold. I’m going to inspect all the wires I can get to first and see what I see. Thank you for posting this! Just goes to show it doesn’t take much!

 

[YezusLX]

Hopefully, when you see what you see, it's something as simple as an old crusty connector that needs a replacement and nothing more. Good luck. Keep us posted. I am learning all about dry rotting plastic myself on my new to me LX. I am hoping that is the case here much better than a rodent's chew toy.

 

[Jasonazx]

Hopefully, when you see what you see, it's something as simple as an old crusty connector that needs a replacement and nothing more. Good luck. Keep us posted. I am learning all about dry rotting plastic myself on my new to me LX. I am hoping that is the case here much better than a rodent's chew toy.

I have a feeling I’ll be handling poop by the end of this!

 

[YezusLX]

I have a feeling I’ll be handling poop by the end of this!

Every amazing resto project starts with poop. Just ask anyone at SEMA they'll be the first to let you know. Haha time to put your COVID respirator to good use.

 

[Jasonazx]

Well, here’s what I’ve found so far. The wiring for the camshaft position sensor. Looked initially like the insulation was pinched at some point (not at the present), so I disconnect from the main loom to get a better look, and here’s what I found. I did scratch at it a little to see if it was in fact a cut, so insulation could be a bit more peeled back, but not much more. Could this be victory or a tease?

 

[jerryb]

Could be. You found it so you ought to fix it.
I'm thinking bad ground or intermittent hot wire.
Low tranny fluid hard shifts, high ignition retard, knock sensor wouldn't do what's in the vid, fuel line plug, air slug.
Purely from watching the vid. Did not read.

 

[YezusLX]

Well, here’s what I’ve found so far. The wiring for the camshaft position sensor. Looked initially like the insulation was pinched at some point (not at the present), so I disconnect from the main loom to get a better look, and here’s what I found. I did scratch at it a little to see if it was in fact a cut, so insulation could be a bit more peeled back, but not much more. Could this be victory or a tease?

View attachment 2972979

Don't break out the beer and strippers just yet. But I think you are on the right track. Keep up the good work my dude.

 

[Jasonazx]

And then I found this ground wire that connects to the hoist bracket super loose.

 

[Jasonazx]

Well those two things didn’t seem to fix it. I do not know how to record or pull codes on the fly in techstream. I recorded af/02 readings but couldn’t figure out how to record anything else. Any advice how to pull codes in real while driving in techstream and record everything?

 

[YezusLX]

Have you checked this out yet? Even I could understand these instructions.

How-To: TechStream In 5 Minutes

Getting Techstream up and running can be a bit of a pain. Hopefully this helps someone get started quickly. Step 1: Purchase an OBD-II / Mini-VCI interface. - I have sold out of my cables and supply chains are back in order, so no reason to purchase more. Anything like this will work: Mini-VCI...

forum.ih8mud.com

 

[2001LC]

The suggestion: check all wire harness, blocks and wires was suggested for a few reasons.

Someone in the previously, routed wrong. Now wire has rub off sheathing, and shorting.
Wire block not firmly attached and possible corroded now. So any loose, inspect closely then attach.
Body grounds, it doesn't hurt to clean metal bare and tighten.
Mikey & Minny mouse have built many homes in valley of the engine. They also love to place pantry in air box. They get in dash through air vent under mold below windshield.

Two most common.
Wire during time belt routed wrong.
Mice.

Keep hunting and repairing. Those broken strands of wire, can cause resistance issues..

 

[Jasonazx]

Have you checked this out yet? Even I could understand these instructions.

How-To: TechStream In 5 Minutes

Getting Techstream up and running can be a bit of a pain. Hopefully this helps someone get started quickly. Step 1: Purchase an OBD-II / Mini-VCI interface. - I have sold out of my cables and supply chains are back in order, so no reason to purchase more. Anything like this will work: Mini-VCI...

forum.ih8mud.com

Oh, I’m in techstream and have used it for other things (vgrs calibration, registering keys, health to find registered codes and fix/clear), but just wanted to confirm I am performing the proper test/selecting the right options for this particular issue. I need to look into pulling codes live. I did figure out how to record.

 

[Jasonazx]

The suggestion: check all wire harness, blocks and wires was suggested for a few reasons.

Someone in the past routed wrong. Now wire has rub off sheathing, and shorting.
Wire block not firmly attached and possible corroded now. So any loose inspect closely then attach.
Body grounds, it doesn't hurt to clean metal bare and tighten.
Mikey & Minny mouse have built many homes in valley of the engine. They also love to place pantry in air box. They get in dash through air vent under mold below windshield.

Two most common.
Wire during time belt routed wrong.
Mice.

Keep hunting and repairing. Those broken strands of wire, can cause resistance issues..

The search will continue! I’ve pretty much finished checking everything in the engine bay without removing the manifold, which is when I found the two issues above. Going to check wiring to transmission next and then pull the manifold if I can’t find anything there.

 

[2001LC]

The search will continue! I’ve pretty much finished checking everything in the engine bay without removing the manifold, which is when I found the two issues above. Going to check wiring to transmission next and then pull the manifold if I can’t find anything there.

When I find 1 wire chewed on. I've always found more signs of rodents.
When looking with flash light under intake manifold. Did you see any signs of nest.
Check the vacuum lines also. Make sure the intakes vacuum line (backside) for the 8 butterflies and others coming from under intake manifold have not been chewed on.

Crank sensor and oil sending unit wire housing routed wrong, is one I find often. They should be tucked behind fan bracket, not in front where they can rub serp belt.

 

[Jasonazx]

When I find 1 wire chewed on. I've always found more signs of rodents.
When looking with flash light under intake manifold. Did you see any signs of nest.
Check the vacuum lines also. Make sure the intakes vacuum line (backside) for the 8 butterflies and others coming from under intake manifold have not been chewed on.

Crank sensor and oil sending unit wire housing routed wrong, is one I find often. They should be tucked behind fan bracket, not in front where they can rub serp belt.

Didn't see any signs of nests under the manifold yet, but it's a bit harder to see under there compared to my 2000 with the induction pump in front!

 

[2001LC]

It is hard to see! What helps, is a $20 drain snake camera, hooked to smart phone. You can also use vacuum gauge to test vac of hoses coming from under out front and rear. Check to see there is vacuum. Cut hose will not.

I'm not overly concern with knock sensors wires. If chewed through you'll get a CEL. If partial cut through, I doubt it cause your issue.

 

[Jasonazx]

It is hard to see! What helps, is a $20 drain snake camera, hooked to smart phone. You can also use vacuum gauge to test vac of hoses coming from under out front and rear. Check to see there is vacuum. Cut hose will not.

I'm not overly concern with knock sensors wires. If chewed through you'll get a CEL. If partial cut through, I doubt it cause your issue.

It’s got to be right under my nose. Can’t wait for this saga to be over with.