vibration/shudder on acceleration (1 Viewer)

[Ebag333]

how could i possibly do that? i was raised in an fj55 that got over 750k miles on it. i'm a die hard for toyota's. i went over the loom with a fine tooth comb last night and it's unscathed. i think i'm going to pull the upper plenum off and check out what's going on. i'm banging my head trying to figure it out. the engine rev's out nicely, the shifting is relatively good, but the shudder has me going. also last night i screwed with it a little and took it out for a drive. NOW i'm also hearing what sounds like a couple pieces of sheet metal clanking a couple times as i'm accelerating at low r's. got home, looked under the iron pig and shook my head at the prospect of pulling the bus tranny. hmmm....

My point was more of that you've only made one post, have diagnosed what you have, and are declaring that "this is it! No more!"

Since you have only made one post (well, two now), none of us know what's going on. There are several things that can cause shuddering beyond the harness....but we can't help you if you give us zero information.

Try posting up what's happening exactly. Better yet, if you can replicate it at will record a video and post it on YouTube. There are quite a few different things we can suggest that might be the problem....but not if we're left in the dark.

 

[mudhogger]

problem solved. it was one of those moments where you just shake your head and open a beer in celebration. rear u-joint on the front driveline. the first time i checked the driveline it felt tight so i figured it's good. drove the truck after tune up, new fluids and same problem. went back under and wouldn't you know it, the u-joint is sloppy. it had fused itself in one direction and would move freely in the other. i've got to say that the factory caps didn't want to come out without persuasion. and yes, i know i've got rookie status here, but i've got years on yotatech. i've had a couple early 70's fj55's, now the fzj80 and my trucks.

 

[skii]

^^ here's to hoping I come to the same solution.

Without any level of consistency I get shudders upon acceleration at 30 and 50mph, always a bit over 2,000rpm. The wiring harness was resting against the egr valve and blackened the point of contact. I re-wrapped and moved the harness away which caused the shudder to go away for a day but it has since returned. As I said the shudder is intermittent but still present. I also had a mouse messing about ripping out pieces of insulation when I was overseas last month.

 

[jtmosca]

Concur with your assessment. I was flat out of time to resolve the issue but the Toyota dealer took care of it for $90.

Its the wiring loom and it happens due to torque from a stop or up a hill.

Very easy fix - much easier than the pesky heater hose.

Troy

Hey Troy,

Hope you are doing well. I bought your 80 last year. It's been running good overall. Quick question: I get a severe shudder similar to what you described in this thread. However, it only happens once in awhile, and only in reverse, and only if I'm backing up an incline (nose facing downhill). It's been a little unnerving (I immediately thought transmission) but this thread is easing my mind. What's your thoughts? Sound like the loom problem you described before?

 

[lcruzrlvr]

Hey Troy,

Hope you are doing well. I bought your 80 last year. It's been running good overall. Quick question: I get a severe shudder similar to what you described in this thread. However, it only happens once in awhile, and only in reverse, and only if I'm backing up an incline (nose facing downhill). It's been a little unnerving (I immediately thought transmission) but this thread is easing my mind. What's your thoughts? Sound like the loom problem you described before?

The problem, pre-resolution, only happened to me going forward intermittently and I was unable to replicate it going in reverse. That was very challenging to diagnose outside of this forum. The Toyota dealership didn't replace the entire loom and you can see their work right behind the air cleaner towards the rear of the engine.

If it isn't that issue, I would look to the front axle - primarily the drive plates as a potential culprit based on 'reversing on an incline' - loading up the front axle with weight.

let me know how it goes.

Troy

 

[jtmosca]

Ok, thanks!

 

[RescueU]

Has anyone ever posted photos or video that visually documents the condition where the culprit was confirmed to due to a fried/overheated wiring loom? I'd really love to get a look at what I should be seeing. I'm actively working on this very problem this morning.

IIRC, someone posted in a similar "shudder" thread that the resolution he found was with a loose cable/wire that connected to the tranny (in a not so readily visible location). I'm still searching for that post...if anyone recollects it and can point me to it, I'd appreciate the help.

I'm in a time crunch to get my LC stable enough to pass VA emissions and state inspection, in order to renew my plates registration/stickers. Until that's completed, my truck's not permitted onsite at the workplace...so in this case, time is definitely money. Thanks for the assistance, fellas.

 

[RescueU]

I found AZ80's post that I referred to earlier:

https://forum.ih8mud.com/80-series-tech/384885-engine-hesitation-stutter-light-loading-new-post.html

Apparently, it was a loose 'transmission control harness'. I'll be looking for that when I get back under my LC.

 

[ECHOAXLE]

Hello Land Cruiser heads! This is is addition to the symptoms described here in this post in regards to the "shudder" when accelerating from a stoplight/sign as if the tranny is slipping or that something is not catching in gear. My symptoms were only after the vehicle has reach peek temperature and I can then notice the shudder and hesitation.

I read on the post that the shift solenoids could be the issue. I did that and made test to the Solenoids after I pulled them out. one was not testing properly and so that was replaced. Installed everything back and thought that should the care of the issue. NOT!!! The shuddering was still there. I even made sure that the tranny oil was at required amount...still the problem did not go away. I took it to a local tranny shop, the shop was recommended by our local 4 wheel parts store...

Then the shafting in my butt started.....The tranny shop called me the day after I left it with them for diagnosis. The manager said the vehicle will not start. What? I told him how to reset the alarm system with the toggle knowing that if they undid the battery that will cause this issue. He said it is still not starting...So, I drove down to the shop and tried it myself...my baby did not start. I push the button and it will crank but will not start at all. I told them this is odd because this beast never failed me and it always starts up even after months in the garage. The manager recommended to have it checked by a mechanic and he asked if I had any local shops I work with. I told him no and thus he recommended an automotive shop just down the road to which I agreed. (I know I'm a dumbass) I told them to just take out the alarm system and maybe it will take care of the issue...after a couple of days, the shop never called thus I made the call to reach out. The lady said it was still not starting and that I will need to have a proper diagnosis which will cost me close to $200. Still after a day, I drove to the shop and asked more intently what they found out. The mechanics was yanking my chain and putting his dick in my ass telling me that he need to bypass a wire because the coil was not firing etc etc etc bull**** and that he ignition turn key thing needs replacement. So I told them What was the actual diagnosis but he did not have one...I told them I'll pay the bill minus the diagnosis and have the LC towed to the local Toyota dealership to "git 'er done" properly.

Man, I can not get a break here...I told toyota service that there is the issue of the LC not starting and told them what had happened and that I think the tranny is slipping and may be broken. Per advise by the previous crook, the ignition turn thing needs to be replaced because it is not starting at all. I even told them the the previous crook got it to crank and start but the ignition may be problematic. So Toyota Service did their thing and called me it is the starter because the voltage is not right down there. I told the jackass that I just serviced the starter with new set of brushes in 2015. He argued with me and so I gave in and went with the recommendation to replace the starter. After Toyota service replaced the starter, the service jackass called to tell me it is still not starting and will need to replace the ignition thingy. I said didn't I tell you that already? So I said go ahead since I just wanted to get the beast running again and get the diagnosis about the SHUDDERING!

Are you all still with me, this is about Shuddering at acceleration from a complete stop right? It gets better I promise. Well, replaced the ignition and got that issue resolved. Thank goodness...So they diagnosed the shuddering and slipping issue as not the transmission which was a huge relief . After a week, Toyota still did not know what was happening but that the test they did showed good compression but have minor change when on load...#3 and #6 cylinder has issues and may have a burnt valve and the injectors are giving issues. OMG!!!!! Okay, go ahead...the tune was quite a lot of benjamins to hand out.

After that fix, the shuddering was still there although minor but still there when I and the Toyota mechanic drove it around. He even showed me where he stepped on the brakes and giving it gas to simulate load and the shuddering was very noticeable. I said I'll just pay my bill and drive my hesitating LC home. After few days of driving, the issue was still very noticeable and still the shuddering kept me puzzled. I said the f word so many times I wanted to cry that my baby is done with...did I mention Toyota recommended an engine overhaul because the issue had to be with the "head gasket" and burnt valve? Yes, complete insert of dick in my ass really. I felt it and it was not pleasant...And I had to pay around $5000 for the fix!!! yes, they bust a load in my ass too!

This gets better stay with me.....

After research here in I8MUD and doing some investigating, I took the recommendation by our mudder community that the Loom or loon of wires by the EGR system near the back of the engine by the firewall may need insulation as the heat can cause disruptions. So I went down to the local auto parts store and bought a 4 dollar insulate tape, 100 degree think insulation... Wrapped that loom or loon of wires. Also, I found that the engine ground wire being the engine was just hanging and attached that to the engine. And per my cousins recommendation, twerk the throttle body sensor a bit and that may fix it.

Wolla!!!! The beast is fixed, beat a freaking mustang that tried to block me from switching lanes and even went to Sequia National forrest and Hume lake last Memorial day week and my baby preformed like a champ. I'm even using it for now as my daily home to work vehicle. Not more issues.

Took my issue with toyota Serivce manager and showed him the log of all the fixes I did to my very clean greaseless engine, which impress him. I told him I bring this up with Toyota about how this thing happened to me.

Well, Toyota will refund me the bill of $1800!!! I am happy and the LC is happy.

Thank you mudder! LC all the WAY.

 

[fj40rob]

Got to throw this one out there guys...

Have you washed the engine lately?

I went through some flood water and mine is acting like this. wont accelerate normally and hits 2nd gear a little hard. what did I get wet?

 

[concretejungle]

pull your spark plugs and see if they are wet

 

[Dishman28]

For what it is worth I just had the same issue on my 97. Thanks to this board we saved my mechanic a lot of time with diagnosis. Told him to check the U Joints and loom of wires by the egr system near the back of the engine. Our issue turned out to be the front U joint. Easy fix thanks to Mud. Rolls like new with 281k.