All my crazy Lexus issues SOLVED!! (ECU-leaking capacitor)
08-07-13, 01:19 AM
#361
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08-07-13, 01:25 AM
#362
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sorry man should have been more specific..
get an LS400 ecu plug (haltech have them, toyota ecu plug which is the same for supra as well)
haltech platnium 1000 ecu for the engine
supra stick auto ecu for the box - http://www.latentsolutions.com/suprastickuv.html
then fit both ecus upto the LS400 ecu plug so its plug and play..
did it on a mates hilux only we used a Autronic and supra stick ecu on his..
pics here - http://smg.photobucket.com/upload?lo...%20v8%20duncan
its since had twin gt28 turbos fitted and made 348hp at 10psi on pump fuel.. with the same ecu combo i fitted..
im planning to go twin gt30's on mine so might as well make the ecu jump now..
get an LS400 ecu plug (haltech have them, toyota ecu plug which is the same for supra as well)
haltech platnium 1000 ecu for the engine
supra stick auto ecu for the box - http://www.latentsolutions.com/suprastickuv.html
then fit both ecus upto the LS400 ecu plug so its plug and play..
did it on a mates hilux only we used a Autronic and supra stick ecu on his..
pics here - http://smg.photobucket.com/upload?lo...%20v8%20duncan
its since had twin gt28 turbos fitted and made 348hp at 10psi on pump fuel.. with the same ecu combo i fitted..
im planning to go twin gt30's on mine so might as well make the ecu jump now..
Last edited by simrx3; 08-07-13 at 05:26 AM.
08-07-13, 06:39 AM
#363
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There is now a discussion on the Gen1 GS300 forum.
My ECU is too far gone to repair - I removed the caps, cleaned the board, and noticed that there were damaged traces on the PCB, one looks to be severed from a plated through hole. This appears to be a multi layer board, so repair looks to be impossible for me. I'm getting another used ECU, hopefully this one isn't too far gone.
08-07-13, 09:45 PM
#364
Hey cowboy, quick question. I took my ecu out tonight to take a look at it. It looks good, but I know you said before that they could look ok but still be bad. I also went ahead and ordered all 8 caps from the list that you provided on the first page. I just copied and pasted just to be sure I had the right caps. The total without shipping was only about $4-5? Does that sound right?
I'm only having two issues with the car.
1- The a/c fans will not come on. (checked all fuses and relays)
2 - Very slow acceleration. Feels like its being held back or I'm towing a huge boat. Every once in awhile it will have a slight studder. No "CEL" either. I have replaced in the past couple weeks the maf/afm and both o2's thinking that might be the issue. I've been driving the car a good while now with the maf unplugged, because it runs 10 times better and has a good amount of power. With it plugged in, it wont get out of its own way. With it unplugged I can smoke the tires all the way down the street....
I guess I'm going to go ahead and replace the caps just to rule that out. But do you think with the symptoms that I described it is in fact the ecu, or could it be something else? Also just so I understand. Here is a picture of my ecu. Are these 8 caps the ones to be replaced?
I'm only having two issues with the car.
1- The a/c fans will not come on. (checked all fuses and relays)
2 - Very slow acceleration. Feels like its being held back or I'm towing a huge boat. Every once in awhile it will have a slight studder. No "CEL" either. I have replaced in the past couple weeks the maf/afm and both o2's thinking that might be the issue. I've been driving the car a good while now with the maf unplugged, because it runs 10 times better and has a good amount of power. With it plugged in, it wont get out of its own way. With it unplugged I can smoke the tires all the way down the street....
I guess I'm going to go ahead and replace the caps just to rule that out. But do you think with the symptoms that I described it is in fact the ecu, or could it be something else? Also just so I understand. Here is a picture of my ecu. Are these 8 caps the ones to be replaced?
08-07-13, 10:29 PM
#365
Lexus Champion
Thread Starter
yes, those are the eight caps that you replace, make sure to be barefoot and wearing all cotton when working on an ECU - and make a drawing of which value cap goes where and the polarities +/- before you begin - and I strongly suggest a lot of practice on old computer motherboards or something, unless you are already great at soldering, an ECU is not the place to learn!
in fact, completely review all of post #1 in my thread for many tips
why did you cut & paste? - I sure hope you ordered the caps via the links, that is how to make sure the right ones are used
the ECU does control the A/C system, although it is usually compressor operation that goes, rather than fans, so that could easily be another issue
the performance issue stands a much better chance of being the caps
in fact, completely review all of post #1 in my thread for many tips
why did you cut & paste? - I sure hope you ordered the caps via the links, that is how to make sure the right ones are used
the ECU does control the A/C system, although it is usually compressor operation that goes, rather than fans, so that could easily be another issue
the performance issue stands a much better chance of being the caps
08-07-13, 11:19 PM
#366
Dont mind my cut and paste. 
I double checked everything to make sure I had the right ones.
I might pick up some tools and do it myself. I've done a little but not a board like this. I already talked to our electrician at work and he said he can do it if I decide not to. He does it everyday on our machines, so I'm sure he could handle it.
I double checked everything to make sure I had the right ones. I might pick up some tools and do it myself. I've done a little but not a board like this. I already talked to our electrician at work and he said he can do it if I decide not to. He does it everyday on our machines, so I'm sure he could handle it.
08-08-13, 06:26 AM
#368
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well ive purchased the caps you recomended for the 93 model..
this is the short term fix till i get to get the haltech and suprastick ecu..
this is what mines doing occasionally
● engine running bad - poor power/acceleration - can be difficult to reach much speed or RPM
● transmission will not automatically shift, only manual shift is possible (mine sometimes wont down shift when you flatten the accelerator pedal as well)
● idle speed rolling up and down, or sometimes too low and sometimes too high
● speedometer not working reliably (sometimes sticks on 0)
● tachometer not working sometimes (sometimes sticks on 0)
so will be interesting to see if it fixes them all..
im an industrial and domestic and automotive electrician.. so know my way around a soldering iron quite well..
this is the short term fix till i get to get the haltech and suprastick ecu..
this is what mines doing occasionally
● engine running bad - poor power/acceleration - can be difficult to reach much speed or RPM
● transmission will not automatically shift, only manual shift is possible (mine sometimes wont down shift when you flatten the accelerator pedal as well)
● idle speed rolling up and down, or sometimes too low and sometimes too high
● speedometer not working reliably (sometimes sticks on 0)
● tachometer not working sometimes (sometimes sticks on 0)
so will be interesting to see if it fixes them all..
im an industrial and domestic and automotive electrician.. so know my way around a soldering iron quite well..
08-09-13, 03:59 PM
#369
Cowboy - Another question. Is it possible that I have an issue with my IACvalve? With my maf plugged in the only issue is having poor acceleration. I was doing some reading and saw a few things about cleaning the IAC. I'm just curious if that could be my issue and not the caps in the ecu. I already ordered the caps and I am still replacing them. I might try cleaning the IAC just to check.
When the maf is unplugged.... Does it use the scu at all? Might sound like a dumb question, but the other week when I changed out the o2 sensors I broke a sensor taking it out. I drove the car all the way across town to a friends shop with the maf and both o2 sensors unplugged and it ran pretty darn good. Great power. I'm just wondering. When the maf is plugged in its using all of the sensors to monitor the motor. When its unplugged, is it just running on a "safe/rich mode" or something?
When the maf is unplugged.... Does it use the scu at all? Might sound like a dumb question, but the other week when I changed out the o2 sensors I broke a sensor taking it out. I drove the car all the way across town to a friends shop with the maf and both o2 sensors unplugged and it ran pretty darn good. Great power. I'm just wondering. When the maf is plugged in its using all of the sensors to monitor the motor. When its unplugged, is it just running on a "safe/rich mode" or something?
08-09-13, 05:51 PM
#370
Lexus Champion
Thread Starter
the IACV is only used to allow a little air into the intake at idle, it doesn't affect performance - however a dirty throttle body can affect performance.
the system uses the built in ECU map when it cannot find the O2 sensors
do you know the replacement MAF was a good one?
did you use the real Denso or Toyota original (Denso) O2 sensors? what were the part numbers?
also - please check for a large vacuum leak or air leak after (downstream) of the MAF, this would account for it running much better with out it!
the system uses the built in ECU map when it cannot find the O2 sensors
do you know the replacement MAF was a good one?
did you use the real Denso or Toyota original (Denso) O2 sensors? what were the part numbers?
also - please check for a large vacuum leak or air leak after (downstream) of the MAF, this would account for it running much better with out it!
Last edited by LScowboyLS; 08-09-13 at 06:19 PM.
08-09-13, 06:44 PM
#371
The maf came from a good running car. So I'm pretty sure its ok. I bought the bosch brand o2 sensors. Tried to save some money.
As far as a vacuum leak. I'll check around and see if I notice anything. Maybe spray any areas that could leak, and see if it revs up a bit? I understand that with the maf unplugged it wont matter if you have a vacuum leak or not (because it has no idea). But with it plugged in, wouldn't a vaccum leak have an affect on the way it idles also. With it plugged in, the car idels wonderful, and very smooth. Cant even feel it running.
Oh I forgot to mention that plugged in vs not plugged in there is a major difference in the pedal "feel"? With it plugged in the pedal feels very stiff. Also when its not in gear the car revs up just fine. It only feels sluggish when you try to put a load on it (in gear).
Say you put it in 2nd gear, and just put your foot dwn to the floor. One second it feels like it wants to move, and then another second wants to bog down.
As far as a vacuum leak. I'll check around and see if I notice anything. Maybe spray any areas that could leak, and see if it revs up a bit? I understand that with the maf unplugged it wont matter if you have a vacuum leak or not (because it has no idea). But with it plugged in, wouldn't a vaccum leak have an affect on the way it idles also. With it plugged in, the car idels wonderful, and very smooth. Cant even feel it running.
Oh I forgot to mention that plugged in vs not plugged in there is a major difference in the pedal "feel"? With it plugged in the pedal feels very stiff. Also when its not in gear the car revs up just fine. It only feels sluggish when you try to put a load on it (in gear).
Say you put it in 2nd gear, and just put your foot dwn to the floor. One second it feels like it wants to move, and then another second wants to bog down.
08-09-13, 07:59 PM
#372
Lexus Champion
Thread Starter
the car can revert back to the ECU map when running without MAF, and this would be much better running than with a MAF plugged in and a large air leak between MAF and throttle body, for example
please disconnect the negative battery cable overnight and then drive car until it has that weak power you described again and then scan for ECU codes and post them here
please disconnect the negative battery cable overnight and then drive car until it has that weak power you described again and then scan for ECU codes and post them here
08-14-13, 10:20 AM
#373
Good news! My caps from digi-key came in yesturday. I'm going to try and get them done in the next week or so.
On another note, just for the heck of it I went to the junk yard and bought another afm/maf. I just put it in, and let it sit for awhile with the neg terminal disconnected. I'm about to leave for work, so I'll see how it drives and post back in a little bit.
When checking for codes, what would be the reason for the CEL to just continue blinking none stop?
On another note, just for the heck of it I went to the junk yard and bought another afm/maf. I just put it in, and let it sit for awhile with the neg terminal disconnected. I'm about to leave for work, so I'll see how it drives and post back in a little bit.
When checking for codes, what would be the reason for the CEL to just continue blinking none stop?
08-14-13, 03:43 PM
#374
Ok, third afm/maf is doing the same thing. So I'm pretty sure that it is in fact the ecu. I kinda thought it was from the start, but just wanted to rule a couple things out.
I still dont have any cel with the maf plugged in, and when I go to check the codes and jump the terminals it just flashes along with the trac light. There is no pattern to it, and it doesnt stop? Why would it do this? Is it doing this because there are no stored codes, or maybe simply because the ecu is not working how it should?
I still dont have any cel with the maf plugged in, and when I go to check the codes and jump the terminals it just flashes along with the trac light. There is no pattern to it, and it doesnt stop? Why would it do this? Is it doing this because there are no stored codes, or maybe simply because the ecu is not working how it should?
