Yamae

Hi Tuha, already Rupert kindly answered your question and I don't need to reply you now. Hope your project is going well. I always wonder, surprise and enjoy reading what you do. Best of luck!

Hi Rupert , I found another guy succeeded to fix LS400 there in UK. Thanks for the report and the input. Your result is proving that the capacitor problems are inevitable even there in UK where the summer heat is quite limited.

RupertD

Hi Yamae ,I have replaced the capacitors in three ECU's now with ones recommended. I did inspect the circuit boards and all the removed capacitors with a big magnifier and there was no sign of any leakage ,just a couple of the capacitors were slightly bulged .I suspect the problem is probably low capacitance due to age ,cannot check this as I no longer have access to a capacitance checker .

Yes the weather here is usually three months of bad weather followed by nine months of winter , the interior of a car can get quite hot though some days 30c+, this is pretty rare though.

I would just like to thank you and LSC again for this information , my 94 feels almost like a new car to drive.

lexbubba90

I want to thank you all also, this tread has answered so many questions of mine just from reading. HOORAY FOR RESEARCH!!!!

I have just got project LS400 and have began the TLC. I have place new caps in online shopping cart (from post #1) and will NOT be soldering them myself. I have a 1uz with "low mileage" imported from Japan, Toyota badges , pulling the oem motor with 36X,XXX miles on it! I know these engines are tanks but Im looking for a fresh start.

P.S. I have no idea how to start my own tread so I can share my build

THANKS AGAIN IN ADVANCE !!!

petebrown

Update on my situation: - i ended up shipping the ECU and the instrument cluster to Jim Walker in the states - Jim replaced all the capacitors and returned to me in quick time.

The instrument cluster is now perfect and all issues resolved - thx Jim !!

Unfortunately the shunting problem still exists. After running some diagnostics on the ECU my mechanic now is thinking that the issue may be with the Throttle Position Sensor (TPS) and has ordered a replacement to be installed tomorrow. My understanding is that when the car is hooked up to the analyser, if they step on the throttle they don't see a response that they are expecting on the readout so this is leading them to think that the TPS could be the problem.

The other option we are considering is a replacement ECU. I have found this company on the web "autoecu.com" and would consider shipping my ECU to them to be rebuilt instead of getting a replacement ECU, which could quite possibly need capacitors replaced again, however i'd like to know if anyone else has used this company and also if it would be worth my while doing this ... that is, once you have the capacitors replaced on the ECU what else does a ECU rebuild involve ? I don't want them to simply take out the newly replaced capacitors and install new ones again.

Just to recap - the car drives beautifully if i accelerate very gently - however any attempt to accelerate quickly and the car starts shunting, jerking losing power etc - particular problem when attempting to go up hills of which there are plenty where i live.

Thoughts - suggestions ?

thx
Pete

Tuha

Thanks Mr. Yamae. That means much to me coming from you.

KA8

iTrader: (1)

Just ordered the caps for my 93. Sometimes I have sticky speedo and my 'o/d off' light flashes but when I tried to get code I couldn't get it in diagnostic mode. The transmission shift fine and no problem with engine either, well idle will dip to under 500 rpm sometimes but other than that good running LS at 242K miles. Will report back once this is done. I remember changing out faulty capacitors on my 1 year old LG LCD TV, after changing them it's still going for 7+years.

petebrown

UPDATE ... all problems FIXED !!

We did replace the TPS last week - however it did not fix the problem. Problem was exactly the same as it had been - shunting at 200RPM.

So for the last week i have just drove the car without accelerating above 2000RPM quickly - probably covered about 250 miles in that time of just cruising and the car has been fine.

Today it just started running beautifully - i couldn't believe it as it was still doing the shunting two nights ago.

I can only surmise that the new capacitors needed some "running in" and are now doing their job properly - can anyone shed any light on that possibility ?

Very very happy now ... if you have the same problem i can recommend Jim Walker in the US to replace the capacitors.

I'll update again in another month to let you all know if problem has gone for good.

thx all
Pete

Shmee

iTrader: (3)

Who is Jim walker?

Yamae

That's not the exact reason but it is partly yes if those new capacitors were stored many months after the production because the internal ESR is increased when not used for too long time and some aging applying certain voltage recovers it.

The biggest reason is the re-learning of the ECU. The ECU needs to study the new conditions re-writing the stored data in the nonvolatile memory. You can find some more about this issue at the post #200 by wfseward96 at page 14 on this thread.

Anyway, congratulations on your big success, petebrown.

python

iTrader: (4)

he is a well known guy who has been fixing the instrument clusters for years,also does caps in the ecm's..u want his email just pm me

Fantastica

Yamae and Cowboy,

New issue that I would like your opinion on. Before I replaced the capacitors I noted an oily substance on two plugs any time I would remove my ECM. Did the capacitor replacement with a company here in Jacksonville Florida, and was still getting a pulsing while accelerating and maintaining speed. Also, I wrapped the wires for the two plugs with a white shop towel so I could figure out which direction the oily substance was coming from.

Yesterday I got a CEL, and a P1633 code with limp mode initiated. I decided to swap the ECM with my spare until I can get the company here to check it. However, when I disconnected the plugs that oily substance was present again. The shop towel had oil on it from the ECU plug side, and was only on one plug. Have you ever seen or heard of this? I can't figure out any way this substance can be getting there since it is not on the inside of the ECM, and it is covered by a kick panel that is dry, too.

Btw, this is for a 1998 Toyota Supra with the 2JZGE VVTi.

Yamae

I only have seen the electolyte which was coming out from capacitors and sorry that I have no idea to identify what you mention.

petebrown

Please PM me for Jim's email address.

Pete

Diwill05

Been following this thread a bit, but I'm no technical person when it comes to electronic boards & such. If it was putting together a car audio system that would be a different story. Anyways, I have a 96 LS400 that started having a rather bothersome whine at idle that would go away during driving. The speedometer would randomly go out, then come back on. Went out to crank the car yesterday, it ran but shut off within 3 seconds and wouldn't crank again... just turn over so I left it alone to avoid starter failure. Perhaps all of these issues aren't related, but I'd rather go ahead and take care of the ECU caps before taking it to a mechanic so I know that won't be an issue. I can take out the ECU, but need someone to inpsect & do the work. I'm located in Panama City Fl if that helps. Pardon any ignorance stated within this post.

Diwill05

Just went out to crank the car and it fired right up, but I noticed the RPM gauge wasn't working... That's never happened before. I guess I have a problem. Could be a stab in the dark, but I suppose this along with the other issues are related to this thread? I'd

Ok... instead of making repeated posts, I've edited this one and would just like to say I finally got the ecu out and examined it. There's only 6 caps as stated and I've already spotted at least 3 very suspect. One looked like it might have a small spot of corrosion (light green stuff) around the legs and board, and two other exhibited the usual brown stuff on the board surrounding it so no doubt parts are getting ordered and the ecu will be shipped off to be repaired if possible. I'd posts pics, but I'm sure all who are familiar already know.

I would to thank the guys who originated this thread and find. This has been a life saver compared to what these local shops would have done to me!