stephen18

Been dealing with this for some time..

The car when COLD will have a hard time shifting into a forward gear, I can go into reverse. If I rev the engine and then shift into D it will go fine, and once warm all is well.

Solenoid connector unplugged makes no difference.

When driving, I can shift into N and rev, and feel as if the car was still partially engaged in gear

When driving, the car will "slip" into second gear sometimes. EX: car floored, and then it shifts obviously wayy to early(2-3000rpms), but I can drop it into L and get back into 1st.

I have done 4-5 drain & refills over 50k miles.

The last drain and refill I pulled the valve body off, and disassembled it completely, cleaning all passages and valves. I swapped solenoids 1 & 2 positions, as well. No change.

235k 1994

On a dyno my HP stays flat.. idk if its related...

Brake torque is at about 2000 rpms in both R and D, slightly low of spec (2200 +/- 150 rpm IIRC) but I'm using the gauge as reference

So at this point I'm thinking it may be best just to swap out a lower miles trans..

steve2006

Unless the shifter alignment is wrong which I doubt unless it has been adjusted in the past you are probably,given all the problems,right to be think of replacing the transmission.

python

iTrader: (4)

get it looked at by a reputable tranny shop in ur area

timmy0tool

iTrader: (7)

these cars are notorious for having bad capacitors in the ECU, which control the transmission as well! i highly suggest you looking into replacing these capacitors, as a general routine regardless, and get back to us.

https://www.clublexus.com/forums/ls4...capacitor.html

LScowboyLS

yeah! - what he said!

stephen18

been done. even have two ecus. same symptoms for both

python

iTrader: (4)

yea..what he said!

python

iTrader: (4)

btw u don't pull out a ecu as a preventative measure..do the ripple test to determine if in fact it has issues.

RA40

iTrader: (6)

Ripple test procedure:
https://www.clublexus.com/forums/ls4...-by-yamae.html

python

iTrader: (4)

thanks ra40

LScowboyLS

the ripple test requires a really high quality voltmeter, which most people do not own (the over $150 kind) to be accurate, so, in fact, DO pull your ECU and inspect the condition of the capacitors, before they corrode and ruin the main circuit board of your ECU!

In fact, given that the ECU on a 97 or older LS400 has a known defective series of capacitors and these are having issues at epidemic levels, and as Yamae points out, these capacitors would be way past their life expectancy even if they weren't from a defective series! - they are 17-24 years old, people! - (like driving around with a 8 year old battery, that's just asking for trouble - capacitors are like little tiny rechargeable batteries, by the way!)

so just order the caps and change them out or have someone talented do the soldering (but you still supply the caps) and just do it, it's easy to remove the ECU and even if it is not the source of your issues, you have prevented a very common LS400 problem and future headaches and you will get to enjoy the smoother shifting and additional low end power that most folks who have done it are reporting!

and this advice goes for you SC300, SC400, and GS300 owners as well!

python

iTrader: (4)

ya but everyone can delve into pin point soldering and risk ruining it altogether. u keep saying epidemic levels..but yet my car is approaching 23 years old and 200,000 miles..people bring their ls 400's problems to me in the town I work in,i talk to every single shop owner about issues they encounter...only 1 did I recommend an ecu fix(95) which was stalling out and other common problems related...guess what,he bought it on ebay over 3 years ago with no problems since. every single problem thread on this forum u link to your caps thread and then thank everyone for the most read thread on this forum...u see the irony in this? yamae's ripple test eliminates or supports the caps issue...that's the start point

Twista4004

Damn, Just started having these issues. REALLY don't want to have to fork big bucks on the trans... smh

stephen18

To the ECU stuff. I already followed the thread and rebuilt it over a year ago. Even my spare ECU has new, correct type, caps in it.

Either way, with the trans unplugged, the issue where it is reluctant to go into gear still exists. Any forward gear.

waseem3000

I had the same issues exactly as you described and changed the transmission from a JDM vehicle and problem fixed immediately. Rebuilding transmission here in the UAE is much more costly and a swap was much cheaper... the solenoids were all good and the ECU fix has not been done yet on the car... have to get around doing that... besides that after the replacement the shifting is perfect and butter smooth... however the parts guy sold me the Lexus WS oil... so far it is working good but I have to change it to the correct TIV as far as I read they are not compatible with each other. I hope it doesnt cause any issues in the transmission with this wrong spec oil... best of luck and I would suggest a tranny replacement as long as it is cheap there in the US or get a tranny shop to look at it as suggested.