All my crazy Lexus issues SOLVED!! (ECU-leaking capacitor)
10-30-12, 04:41 AM
#91
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Are there any good ecu's now for sale in Japan?
Thanks yamae for your input
Edit: No there aren't any good one's for sale now.
But: Do you think that if i replace those capacitors in my own ECU whould solve the problem?
Thanks yamae for your input
Edit: No there aren't any good one's for sale now.
But: Do you think that if i replace those capacitors in my own ECU whould solve the problem?
Last edited by Dutchy; 10-30-12 at 01:21 PM.
10-30-12, 04:16 PM
#92
Moderator
In order to fix it you have to completely clean the Air Assist Fuel Injector Lines. The 1UZ-FE engine has an air assist fuel system which is described as below.
http://blogs.yahoo.co.jp/ks1106spiderman/1099329.html
The clogged lines limit the air to go to the path located next to the injection holes indicated by arrows at the third drawings. As the car aged and carbon deposits are accumulated, the air flow is limited. This causes the idle not stable or even it stops. As far as I know, the complete cleaning is not easy to be done and the best way is to replace all the injectors to new ones as well as cleaning the whole intake lines.
Instead of doing those, to use an ECU that has a newer engine management system can prevent the stalling problem if the lines are not clogged completely.
11-01-12, 01:27 AM
#93
Toyota has started to use Nichicon's electrolytic capacitors that contain “quaternaty ammonium salt / compounds" in the late 80s and has kept using them for a bit more than a decade. The reason why they have used those capacitors was simply because the internal impedance was low enough and showed good performance removing noise and ripples at DC lines.
A little before that many electronics industries in Japan have started to use similar capacitors that are for non automobile use and faced serious leaking problems in early 90s at the market.
The details are written below but all in Japanese.
http://ednjapan.com/edn/articles/1208/01/news006.html
I don't have time nor the ability to translate the whole contents but I just translate the title.
“80年代末期の“亡霊”に注意” or “Watch out for the “ghost” in the late 80s”
The “ghost” here means the electrolytic capacitor which contains infamous “quaternaty ammonium salt / compounds". Judging from the title, it is surely dangerous to use this type of capacitor without any special countermeasures.
Most of the electronics companies in Japan have stopped using this type of capacitors in early 90s or mid 90s for fear of leaking problems. But many automobile industries were kept using them needing a good performance. The another reason why so was that they have been in use of high reliability types. Nichicon has been manufacturing special versions of this type for the automobile industries using specially coated lead wires with special sealing rubbers. One of my colleagues has evaluated them and found much better than those types designed for home appliances applications but the life was not as long as those electrolytic capacitors that use regular liquids. Also the high reliability types were very expensive. I can not show you the detail of the evaluation result but at least I can say is that the life is longer than roughly 10 years but you can not expect a lot if used more than that.
As I fix different ECUs as a volunteer, I find many failed Nichicon's PF(M) type capacitors these days, some 12 years old, some 15 years old. What I can say now is that my colleague has done a good job evaluating the capacitors using an oven with the accelerated mode.
In accordance with that and my actual experience, ECUs older than 12 years are ready to fail someday soon or later, I can say.
Below is the failed capacitor used in a 97 Celsior. You can see how the leg was corroded and the leaked liquid was there on the board.
Those who want to replace Nichicon's type PF(M) capacitors to avoid future problems, be sure to use low ESR type capacitors. Never select capacitors just seeing the voltage and the capacitance. I recommend you to use Rubycon's type ZLH or Nippon Chemicon's type KZH. These do not contain infamous "quaternaty ammonium compounds" but their ESR is low enough. You also have to pay good attentions against electric static discharge when doing the replacing job. A wrist strap is definitely needed to use. Without it you might damage the ECU.
A little before that many electronics industries in Japan have started to use similar capacitors that are for non automobile use and faced serious leaking problems in early 90s at the market.
The details are written below but all in Japanese. http://ednjapan.com/edn/articles/1208/01/news006.html
I don't have time nor the ability to translate the whole contents but I just translate the title.
“80年代末期の“亡霊”に注意” or “Watch out for the “ghost” in the late 80s”
The “ghost” here means the electrolytic capacitor which contains infamous “quaternaty ammonium salt / compounds". Judging from the title, it is surely dangerous to use this type of capacitor without any special countermeasures.
Most of the electronics companies in Japan have stopped using this type of capacitors in early 90s or mid 90s for fear of leaking problems. But many automobile industries were kept using them needing a good performance. The another reason why so was that they have been in use of high reliability types. Nichicon has been manufacturing special versions of this type for the automobile industries using specially coated lead wires with special sealing rubbers. One of my colleagues has evaluated them and found much better than those types designed for home appliances applications but the life was not as long as those electrolytic capacitors that use regular liquids. Also the high reliability types were very expensive. I can not show you the detail of the evaluation result but at least I can say is that the life is longer than roughly 10 years but you can not expect a lot if used more than that.
As I fix different ECUs as a volunteer, I find many failed Nichicon's PF(M) type capacitors these days, some 12 years old, some 15 years old. What I can say now is that my colleague has done a good job evaluating the capacitors using an oven with the accelerated mode.
In accordance with that and my actual experience, ECUs older than 12 years are ready to fail someday soon or later, I can say.Below is the failed capacitor used in a 97 Celsior. You can see how the leg was corroded and the leaked liquid was there on the board.
Those who want to replace Nichicon's type PF(M) capacitors to avoid future problems, be sure to use low ESR type capacitors. Never select capacitors just seeing the voltage and the capacitance. I recommend you to use Rubycon's type ZLH or Nippon Chemicon's type KZH. These do not contain infamous "quaternaty ammonium compounds" but their ESR is low enough. You also have to pay good attentions against electric static discharge when doing the replacing job. A wrist strap is definitely needed to use. Without it you might damage the ECU.
11-01-12, 02:05 AM
#95
Moderator
Yes, all this may be true, however there is a second problem with those failed caps: The heat range is only 85 degrees Fahrenheight. Typically the problems are with cars that are in hot climates in the United States, where parked in the sun the interior gets upwards of 120 Fahrenheight. The caps have a temp rating of 85 F. They all leak anyway, but these leak much soonefr than military spec caps. So, you want to make sure the temp rating on your new caps is NOT 85 F but 115 F.
Fahrenheight？
Your spell Fahrenheight is not correct though.You must understand that the world uses Celsius. Capacitors ratings are not based on Fahrenheit but based on Celsius.
11-01-12, 07:17 AM
#96
Moderator
As far as I have experienced, many old ECUs picked up at the junk yard have some problems except collision cars. The reason is very simple, mechanics / owners could not fix the problem
and the cars were sent to the junk yard.
ECU related problems are not simple and owners tend to give up to keep the car. So it would be a good idea for you to replace those infamous caps.
11-01-12, 09:45 AM
#97
Lexus Champion
Thread Starter
You made 2 mistakes. You must be careful when you post.
The main error he made is confusing the operating temperature with the ambient temperature
Yamae and I both are electrical engineers, people, please understand that you need 105C temp caps and low ESR type, of the brand names and types specifically mentioned by us earlier in this thread - don't question it, just do it!
11-01-12, 11:04 AM
#98
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LScowboy
Do you have an extra set of capacitors on your shelf left over??
When i get the right ECU from aussie, i want to change them. Not by myself, but by somebody with more experience.
Greets Dutchy.
Do you have an extra set of capacitors on your shelf left over??
When i get the right ECU from aussie, i want to change them. Not by myself, but by somebody with more experience.
Greets Dutchy.
11-04-12, 04:58 PM
#99
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I finally pulled the ECU on my 93 LS400 and replaced the caps. At first I just replaced a couple of caps that had visible leakage but nothing improved. I went back in and replaced the others even though they looked okay and now the car is running really good. No more throttle issues.
Thanks for the info!
Thanks for the info!
11-04-12, 07:05 PM
#100
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Lscowboyls & yamae
I'm planning to buy the following ECU for my 1996 LS 400. from ebay
www.ebay.com/itm/360500897819?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
Need opinion/ suggestion
I'm planning to buy the following ECU for my 1996 LS 400. from ebay
www.ebay.com/itm/360500897819?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
Need opinion/ suggestion
11-04-12, 10:15 PM
#101
Moderator
I finally pulled the ECU on my 93 LS400 and replaced the caps. At first I just replaced a couple of caps that had visible leakage but nothing improved. I went back in and replaced the others even though they looked okay and now the car is running really good. No more throttle issues.
Thanks for the info!
Thanks for the info!
You could save more time if you have replaced all the Nichicon PF(M) capacitors at the first time. Those capacitors could not be checked by eyes. You need an impedance meter to check. Just replacing them would be a smarter idea for your LS400 life.
Last edited by Yamae; 11-04-12 at 11:56 PM.
11-04-12, 10:23 PM
#102
Moderator
Lscowboyls & yamae
I'm planning to buy the following ECU for my 1996 LS 400. from ebay
http://www.ebay.com/itm/360500897819...84.m1423.l2649
Need opinion/ suggestion
I'm planning to buy the following ECU for my 1996 LS 400. from ebay
http://www.ebay.com/itm/360500897819...84.m1423.l2649
Need opinion/ suggestion
1, The failed ECU can not be judged by a CEL.
2, Those capacitors can not be checked by eyes as fattroot has experienced lately.
If I were you, I just would replace capacitors without buying another ECU spending extra money.
I also think that the ebay ECU would need new caps someday soon.
11-05-12, 02:24 PM
#103
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Dear Yamae
Thanks for your input.
I like to add some additional symptoms of my car. All the stall and engine idle issue happens during summer time and as far I remember it never happened in last winter (even after long drive). Also my speedometer needle become nonresponsive in summer. BTW I live in NYC and we experience quiet harsh summer and winter.
I came across a TSIB memo dated back to 1997 regarding my make and model of Lexus (attached). It's suggesting to change the ECM (previous part # 89661–50302 to be replaced with part # 89661–50303). I have to check which one is currently inside my car.
The reason I'm a little shaky is that I'm not at all comfortable with any job done by me. So I have to find somebody first to swap the ECM (if I have the 302). If that works then I have one ECM to work to change capacitor.
So far this is my plan.
Also I like to ask you, what kind of auto shops will be the best for the ECM job (changing the capacitor)?
Thanks.
Thanks for your input.
I like to add some additional symptoms of my car. All the stall and engine idle issue happens during summer time and as far I remember it never happened in last winter (even after long drive). Also my speedometer needle become nonresponsive in summer. BTW I live in NYC and we experience quiet harsh summer and winter.
I came across a TSIB memo dated back to 1997 regarding my make and model of Lexus (attached). It's suggesting to change the ECM (previous part # 89661–50302 to be replaced with part # 89661–50303). I have to check which one is currently inside my car.
The reason I'm a little shaky is that I'm not at all comfortable with any job done by me. So I have to find somebody first to swap the ECM (if I have the 302). If that works then I have one ECM to work to change capacitor.
So far this is my plan.
Also I like to ask you, what kind of auto shops will be the best for the ECM job (changing the capacitor)?
Thanks.
11-05-12, 03:18 PM
#104
Lexus Champion
Thread Starter
I don't know of a good shop, what you need is a good solderer!
do you know any women who are employed in the electronics assembly and manufacturing field, they usually hire women as solderers because they have more patience!
a good 40W soldering iron is cheap from radio shack, and you want to use the 63/37 leaded solder
just be careful with the 4 grey ribbon cables attaching the boards together, they won't take any rough handling
also wear all cotton clothes and bare feet when fooling around on the interior of the ECU
do you know any women who are employed in the electronics assembly and manufacturing field, they usually hire women as solderers because they have more patience!
a good 40W soldering iron is cheap from radio shack, and you want to use the 63/37 leaded solder
just be careful with the 4 grey ribbon cables attaching the boards together, they won't take any rough handling
also wear all cotton clothes and bare feet when fooling around on the interior of the ECU
Last edited by LScowboyLS; 11-05-12 at 03:22 PM.
11-05-12, 04:55 PM
#105
Moderator
Hi sumon.
So you are not comfortable doing a soldering work. As LScowboysLS has suggested, by experienced women is a good idea. You also could ask someone who has experienced to replace capacitors for PC motherboards.
If I were living closer to you, I could do it free for you as I do at the shops nearby as a volunteer here in Japan.
Many local mechanics here are not good at handling soldering irons to replace capacitors although I advise them how to do precisely. Some tried but the polarity was reversed or the poor soldering did not fix the problem. But they laugh at me seeing my mechanical work such as oil seal changes or belt changes. They say, " You are too slow and we can't stop helping you to use our lifter quickly."
As proverbs say, "Every man knows his own business best / One should go to specialists for the best results." So we are helping each other.
So you are not comfortable doing a soldering work. As LScowboysLS has suggested, by experienced women is a good idea. You also could ask someone who has experienced to replace capacitors for PC motherboards.
If I were living closer to you, I could do it free for you as I do at the shops nearby as a volunteer here in Japan.
Many local mechanics here are not good at handling soldering irons to replace capacitors although I advise them how to do precisely. Some tried but the polarity was reversed or the poor soldering did not fix the problem. But they laugh at me seeing my mechanical work such as oil seal changes or belt changes. They say, " You are too slow and we can't stop helping you to use our lifter quickly."
As proverbs say, "Every man knows his own business best / One should go to specialists for the best results." So we are helping each other.
