Small update. I finally got around to ordering a new set of NGK spark plug wires and Denso double platinum spark plugs. I'm rather curious to see how bad my original 1996 plugs & wires actually are when I change these out haha.

Also random quick question. I want to get a spare ECU at some point. Will ANY ecu from a 1995-1996 LS400 work plug-and-play from a junkyard or ebay if I must? I have a buddy who is good at re-capping stuff & he offered to fix up a spare ecu for me.

I know a 1997 ecu wont work because of the key chip setup (my 1996 doesn't have a programmed key)

 

yes any 95-96 model year ECU should work.

 

Installed new spark plugs and plug wires today. Gotta love it when you get to the very last spark plug you have to install and this is what you find in the box:

Had to use another car and make a run to the local auto parts store for a replacement, ugh! Lol.

Shiny new NGK wires:


A view of the old spark plugs:


The car seems to idle & rev a bit smoother. I'll see if it feels any better when I take it to work tomorrow, although I doubt there will be much difference there.

The old wires were an odd brand I have never heard of. Mitsuba I believe they were. Is that what the car originally came with from the factory?
I know the NGK wires I pulled out were not original, but they were in far better shape then the old plug wires.

Next up is the Caps & Rotors. Hopefully easier to replace compared to the plugs & wires.

 

Mitsuba is a wire/cable company in japan so it is possible they are original.

I can't recall if it was mitsuba or NGK or Denso that did the 95-97 spark plug wires.

 

Last night I had the ECU out of my car. I had a friend who is good at replacing capacitors and fixing other electronic circuitry open it up and take a look at the circuit board inside, needless to say physically the ecu looks brand new in my car. All the caps are perfect looking, traces are perfect, no corrosion anywhere at all, He told me I shouldn't have any issues with my ECU for a very long time.

I took a close look at it myself and it does look "brand new" inside. On both the back side of the board and the inside. These dying ecus for some people- is it possible since these ecus even though they are the same, there are a couple different part numbers where they were perhaps built in different factories with different batches of parts?

 

Did your friend test the ECU capacitors? Have you done the "ripple test" per Yamae's intsructions?

You can't diagnose visually. And yes, some ECUs have aged better than others, though it can't be traced back to batches or different part as that information is not made public. It's sheer luck of the draw what you end up with.

 

We didnt do any testing beyond just a very picky visual inspection of everything. For now I'm just going to run with it until I can get a spare ecu that has already been reconditioned.

Next plans are to replace the engine's primary coolant temperature sensor to make sure im squeezing the most mpg from the engine, and make sure it runs the best as well. It already seems to run amazing, but so far with mixed driving it appears im getting almost 400 miles to a tank. I know I should be getting closer to 500 miles to a tank.
I still gotta pick up new caps & rotors as well to finish my ignition tuneup.

Out of curiosity, does anyone here have a spare cd-changer glovebox in gray? Mine is beat up and junk.

All that aside I've put almost 2,500 miles on her already. Car hasn't missed a beat and only seems to run and drive better the more little things I fix up.

 

A new problem popped up recently.
So, over the past week I've been smelling a oil burning smell, but not the kind from being burnt by the engine. More like oil on hot metal... Started stressing about it when I opened the hood and a small cloud of smoke would occasional come up by the driver's side header manifold.

Decided to jack it up after work and have a look. I was holding off on it because I've been fighting a cold and lacking motivation to crawl under a car after work.


WELL THEN! I was planning on changing the oil anyway. A rock must have hit the oil filter, you can see where my light is shining a pinhole and a trail of oil oozing from it. Wonderful!
Its a slow enough leak that the oil level of the engine hasn't gone down much at all. Enough to blow all over the exhaust from driving on the highway though.

Gotta say, I couldn't have asked for an easier fix to this new problem!

 

Before you do anything else replace your ECU. I just did and it is a brand new car. I was ready to do a MAF clean and a tune up and now this thing revs to 6k like my old GSR...

 

My car revs and pulls like a raped ape with the current ecu.. To me anyway lol. Also does perfectly fine on MPG, 470 miles out of my last full tank of fuel with very mixed driving. I'm not worried about the ecu for now, its doing its job.

So today I found another leak, and it looks like its an auto transmission fluid line that goes in front of the radiator. I say this because the fluid that comes out of it is red and smells like ATF. When my last ATF leak was fixed they replaced all the lines that go up to the radiator.

This line that goes in front of the radiator is an ATF line, correct?

This passenger side next to the electric fan weeps the worst.

It weeps out on both sides where the rubber hoses are held on with clamps. I'm hoping I can just get some new rubber lines- a tad longer then the current ones and clean up the metal ends with sandpaper. Go a bit further past the rust up the metal line and clamp it there. Thoughts on that guys? Also does anyone happen to know the diameter of the rubber hoses (one on each side) id need to get?

 

That is your power steering return line. Should be a 3/8" ID hose. It looks like ATF because it is. The LS400 uses Dexron ATF for power steering fluid. Never add power steering fluid to the power steering system on your LS400. The wetness is above that hose connection you pictured so make sure the leak is not above that and running down the hardline to make that connection look to be the culprit. It's all much easier to see if you remove the air cleaner assembly. But it could just be spraying out some with the amount of fluid sprayed over the fan from the looks of it. Have someone sit in the car with it idling and turn the wheel back and forth, watch that spot while that happens.

 

Thanks for confirming!
Ahhh you are correct! Makes sense considering I just had to refill my power steering fluid a couple days ago. (Yes, I used Dexron rated universal import fluid)
Today I picked up some better hose clamps and 2 feet of power steering rated 3/8" hose. For now I have the hose clamps added to the leaking ends and it seems to have slowed the leak down a lot. Waiting until a friend of mine who has more experience repairing a leak like this to come by and lend a hand. He also knows how to bleed the PS system of air when we do the repair. I've never done it before so I'm going to wait for his help.
So far the idea is to cut off the rusted ends, sand the lines clean and use the new longer hoses to push them further up the clean un-rusted part of the line and of course use the new hose clamps on the ends.

I'm sick of leaks lol. Hopefully this is the last one for a while. The engine doesn't seem to leak any oil, or any noticeable amount anyway. Transmission is good now after having ALL the lines replaced earlier. Slowly getting her fixed up!

 

Dont overthink this. First of all, being that you are working on the return side of the circuit, no bleeding is needed after the repair. Secondly, take it easy cutting off any corroded metal lines. Remove the hose section and inspect from there. Try cleaning the area where the hose sits with a scotch-brite pad first. The leak is likely from a degraded hose rather than being corrosion related. But I could be wrong. Just don't go cutting anything unless you see the problem there.

 

Thanks for the tips. I appreciate it!

Another thing I wanted to mention that I keep forgetting because its SUPER MINOR, most the time you cant even feel it but sometimes you can-
Stopped at a light after its all warmed up the car has a vibration, feels like a HUMMM (but without a sound) going through the body of the whole car.
It also has this same hum (just in "waves") when the engine is at a fast cold-idle and the car in park.
100% positive its not a misfire or hesitation. I know what those sound and feel like. Much more pronounced feeling compared to what this is. I have a very picky ear for when an engine is missing, and mine is running fantastic.

This vibration is intermittent and goes away when driving at any speed. Even idling with the brakes off. I have already done some searching and as many other have said 99% of these vibrations come from tired engine & transmission mounts. After 200K miles, I know my engine & trans mounts gotta be tired and worn out.

Minor issue... just making a note.
The sensation is so small that I don't think anyone else who has ridden in the car with me has even noticed. Most are used to lesser cars that are less smooth. I just am aware the level of perfection this car in perfect shape can have compared to others.

 

Well the power steering cooler line has been replaced with a line in perfect condition from a scrap yard & the hoses attaching to it were replaced with new power steering hose.. One leak and problem fixed- but another problem has been created.

My power steering system does not work at idle/low rpms. If I hold it at around 1500 rpms it works on and off. Otherwise the power steering is simply not working. The pump isnt making any bad noises.

My guess is that there is a bunch of air introduced into the system now. It worked fine before- just leaked. The leak is repaired but now the PS system isnt functioning correctly.