LS 400 Issues
06-07-12, 09:51 PM
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LS 400 Issues
Hey yall. I wanted to list some of the issues I had with my LS400. I dont think it needs too much to be where it is 100% reliable, but I'll need help getting there. This is what I got.
Drive - Hesitates will pick up and wont gain any power until after 40 - 45mph then it kicks in hard and smooths out beautifully. Feels like its stuck in limp mode or something. Some stumbling too!
Stop Light - Car wants to jump like it wants to go even when I am holding the brake! Scary!
Rack An Pinion - Has a leak coming from it.
Previous owner said the water pump, timing belt, tune up were all recently done.
I PERSONALLY think that he may have the timing off or even the spark plug wires in the wrong place, so I will have to get my hands on a spark plug wire diagram to see where what goes.
The ignitor on the left side of the engine, more so towards the passenger side is tapped up and the clip from the spark plug is only clipped on one side. Not sure if that matters.
I know the transmission fluid was never drained and filled with fresh fluid, so that may be an area to look at too. Im going to fill up with 93 and throw some techron plus in there for good measure. This worked great in a police interceptor I use to borrow, so unless you guys tell me otherwise, Im using it!!!
TPS, MAP sensor, I dunno guys, its alot of variables. I am curious if anyone every got a definitive answer on what makes the hesitation occur in the 91 - 94 LS400 series Lexus from 1st to 3rd gear in between 0 - 45mph. It sucks so bad because when it clears up, she so silent, it feels smooth. Other than the occasional stumble here and there shes fine. Any help would be great, Thanks!
Drive - Hesitates will pick up and wont gain any power until after 40 - 45mph then it kicks in hard and smooths out beautifully. Feels like its stuck in limp mode or something. Some stumbling too!
Stop Light - Car wants to jump like it wants to go even when I am holding the brake! Scary!
Rack An Pinion - Has a leak coming from it.
Previous owner said the water pump, timing belt, tune up were all recently done.
I PERSONALLY think that he may have the timing off or even the spark plug wires in the wrong place, so I will have to get my hands on a spark plug wire diagram to see where what goes.
The ignitor on the left side of the engine, more so towards the passenger side is tapped up and the clip from the spark plug is only clipped on one side. Not sure if that matters.
I know the transmission fluid was never drained and filled with fresh fluid, so that may be an area to look at too. Im going to fill up with 93 and throw some techron plus in there for good measure. This worked great in a police interceptor I use to borrow, so unless you guys tell me otherwise, Im using it!!!
TPS, MAP sensor, I dunno guys, its alot of variables. I am curious if anyone every got a definitive answer on what makes the hesitation occur in the 91 - 94 LS400 series Lexus from 1st to 3rd gear in between 0 - 45mph. It sucks so bad because when it clears up, she so silent, it feels smooth. Other than the occasional stumble here and there shes fine. Any help would be great, Thanks!
06-08-12, 06:44 AM
#2
After purchasing my 1995Ls I have done what I consider maintenance and it has improved the driveability of the car. This included a complete throttle body cleaning, changing the fuel filter and a fuel system cleaner added to the fuel tank. I know that the earlier Ls like yours suffers greatly from a dirty throttle body so it wouldn't hurt anything to start there.
06-08-12, 06:48 AM
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06-08-12, 06:58 AM
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06-08-12, 06:59 AM
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After purchasing my 1995Ls I have done what I consider maintenance and it has improved the driveability of the car. This included a complete throttle body cleaning, changing the fuel filter and a fuel system cleaner added to the fuel tank. I know that the earlier Ls like yours suffers greatly from a dirty throttle body so it wouldn't hurt anything to start there.
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06-08-12, 07:19 AM
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I can tell you that mine was, and I'm guessing here, 40% blocked. The filter element was really dirty compared to the new one and I could hardley blow through it. If you are going to clean the throttle body, I suggest removing it from the car. It will be so much easier. Also you need to make sure whatever cleaner you buy is for throttle body's and is safe for O2 sensors and catalytic converters. Don't forget the new gasket, you will need one of those too.
06-08-12, 10:05 AM
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ONLY use toyota type IV red tranny fluid. do not mess with this. you don't want a failed tranny on top of the engine problems. and don't let anyone, no matter their credentials or reported experience, talk you into a power flush. there are numerous threads on this topic. search those.
06-08-12, 12:29 PM
#11
If you read the owner's manual or the dipstick for the trans, it will tell you the type of fluid that you should be using. If it recommends Dex/Merc, than any generic ATF will work, provided it's not a specialty ATF (like "for imports" or "domestics") If the vehicle calls for Type II ATF, than you should use Type IV ATF, as it supersedes Type II. I believe that when I built my A340 trans, I used O'Reilly's ATF which is Dex/Merc.
As stated above, Toyota recommends drain and fills, and not to flush them as they want a little remaining fluid left over to transfer any wear/friction modifiers that might still be in the system. Not saying if you do flush it you will have problems, I can just tell you as a once Toyota Tech, that's how our dealer was trained in our T-Ten courses.
As stated above, Toyota recommends drain and fills, and not to flush them as they want a little remaining fluid left over to transfer any wear/friction modifiers that might still be in the system. Not saying if you do flush it you will have problems, I can just tell you as a once Toyota Tech, that's how our dealer was trained in our T-Ten courses.
06-08-12, 03:23 PM
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Great stuff guys tnx! So Toyota or equivalent ATF, Fuel Filter and drain and fill.
Already did the fuel cleaner with the techron and will go thru the weekend of driving to see how it interacts with the fresh 93 octane fuel in the tank.
Already did the fuel cleaner with the techron and will go thru the weekend of driving to see how it interacts with the fresh 93 octane fuel in the tank.
06-08-12, 03:50 PM
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+1 on that. We had a perfectly good Nissan Stanza and a power flush was recommended by a mechanic. We had it done and the tranny never worked quite right after that.
06-08-12, 06:14 PM
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It's the 98 and up that ya dont need to change the fuel filter, I think they're listed as a lifetime filter. That's why they are mounted up where it's a real PITA to get to. Not like ours, nice and easy. Change your ECT sensor (search) it might help a little with the hesitation.
06-09-12, 04:52 PM
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https://www.clublexus.com/forums/per...-i6-sc300.html
For others who may run into the same problem, this will help all. I will be checking into this and attempt the replacement myself if I can. Otherwise, its a trip to the mechanic. Tnx!