CMDSlick

Python,

Yeah... exactly. The car runs fantastic most of the time, but this one thing is really nagging me.

Like I said in my previous post I'm beginning to suspect the tranny. The poor acceleration seems to happen more frequently at turns or after, but I'm beginning to think it's not downshifting rather than a power issue. But one time specifically I'm thinking about I went around a corner and kept my foot consistent on the accelerator. It was sluggish, and then seemingly stepped up in power twice about 3 seconds later and 4 seconds later. The rpms stayed consistent from what I remember, however they could have increased... can't remember.

I'm pretty sure if I can get this figured out, I'll have about another .5 to 1 mpg. I'm really thinking it's the ECU which is controlling the shifting and power output of the tranny. I'll know this week. My friend is coming into town to help me with this problem this week and already have the capacitors to ensure my ECU works for a long time.

Kram

just got back on line and read your story.I had the same problem with my 1990 and when you said you replaced the temp sender you did not mention which one -there are 2- and the one that needs to be replaced is really hard to get to, so you should know if you replaced the ecu temp control or the engine temp control.the ecu temp control is always going to give you the bad gas mileage because it tells the ecu what temp the engine is at so the timing/injecters work at their best settings .The ecu temp control is located just behind the thermostat housing and down in the valley . They say it takes 4 hours to change out but I did mine in half an hour and it cost lest then 40 dollars for the part .I hope your new coils fix the problem but I did the same thing as you did and I still had to replace the ecu sensor.About the rear o2 sensors I have never had to replace one yet on any of my lexus cars and I have 3.There are alot of members that know about the ecu temp sender just ask anyone.

python

iTrader: (4)

manually downshifting would give u some sort of an idea

CMDSlick

Ok... So finally got my capacitors changed on my ECU. Ordered them weeks ago, and my friend got into town late this last week, and finally changed them out today. No problems, went fairly smooth.

So far with an initial test drive, I seem to notice better performance and didn't experience the sluggishness I've been seeing. However, they were short drives and haven't obviously had a lot of time to see if there are the symptoms I've been experiencing.

I am super happy to know that these caps will likely last the life of the car and looking forward to many years with my black beauty. For those who might be interested, I bought double the needed caps, and would happily ship them to someone for shipping costs. For a '93.

I'll keep everyone posted.

Yamae

Congratulations on your success to fix,CMDSlick.
The only regret is that you should have done it quicker following the #2 post by Legender.

Anyway, I'm glad that you now feel the performance is better too. I always suggest people who own an old LS400 to replace ECU capacitors as a preventive measure before to have serious problems. It only costs $10 for a DIYer and he/she can expect a better performance as well as escaping from unexpected peculiar problems that no one considers caused by the ECU.

Your suggestion to ship spare capacitors to someone who is seriously needed is a very good idea. I like the way you try to help people. There wiil be another happy owner soon.

CMDSlick

Thanks Yamae. I try to pay it forward as much as possible, and I have gleaned so much here already.

Yes I wish I had done it sooner! It was one of the items on my list, but unfortunately I was at the mercy of my friend who could help me with this. Just glad that it is done and for your efforts helping find the culprit on the other posts.

I'll keep people posted. Hopefully this is it!

Legender

Happy to help.. and more importantly... you got the car running like it's supposed to and can get back to enjoying the ride..
I've only shared what I've learned from this awesome site and the great people that support it.

CMDSlick

It's looking really good! Went on a longer drive today, and notice quite a bit of a difference. At a few points when I just was thinking about something else (work most likely) and was just driving, I was almost shocked out of my normal thoughts because of the difference in response. I also am not noticing any decrease in power after the car has warmed up. I would highly recommend changing out the capacitors even if you aren't noticing a lot of problems. I think you'll be pleasantly surprised.

Thanks again everyone.