IBGREEZY

I have not checked the capacitors using an ohm meter. My caps looked fine before I replaced them, I just assumed they were bad and did preventative maintenance (no actual leakage). I was having this starting issue before I replaced them and wanted to be able to rule out the ECU as the culprit. I am not sure what would be causing a "safety shutdown". Would this be an action controlled by the ECU or the theft deterrent system? I am out of ideas as I have been working on this no start issue for the past month and it has me questioning my troubleshooting skills (or lack thereof) .

evoltap

Thanks Yamae. Although I guess I can't rule that out, I think I wasn't totally clear: one ECU I have has visible damage, the one I re-capped and have in the car has no visible damage. I just want to be sure the issues I'm experiencing are ECU related and not something else. The symptoms are that the car will start and idle fine and rev fine up to 5k rpms, etc. but feels a little rough. When I drive it, it stutters when shifting to 2nd and 3rd and if I try to accelerate too much, it will just stall. It will then start but if and when it stalls again, it will not start. Disconnecting the battery for several hours then seems to get it to start. During this time it won't start, there's a smell like starting fluid (I haven't used any). Do I need a new ECU? Thanks again.

RugbyDad

Things like this are hardly ever just a one thing. Its probably quite a few things. I would start to look at the fuel system. A clogged fuel filter will allow for a car to start but once the engine is placed under load, ie heavy acceleration, the fuel requirements are increased and the fuel filter can't pass fuel through adequately. Also a bad fuel pump will exhibit some of the same symptoms as what you are describing as far as the car stalling and sputtering.

Get them diagnosed ASAP. A full inspection may be necessary. (Not a emissions and safety inspection, but more like a PPI).

Yamae

Judging from your words "I was having this starting issue before I replaced them" , your problem sounds like an issue not related to those capacitors to me.

Yamae

Sounds like you have a fuel related issue. The 5K rpm limitation may be caused by the fuel supply shortage, I assume.

evoltap

Thanks for the advice. So even though I replaced my ECU caps, I may be on the wrong thread. Just to clear up one thing, it most likely will rev past 5k rpms, that's just as far as I've rev'd it. In other words, it will rev high and normal when it's in park, it only fails when driving, and usually when shifting around 2nd or 3rd gear. One final piece of information that I discovered today is that in the 100 degree Texas heat with direct sun, it won't start at all-- once it's night and it drops to 80 or so, it starts right up. Do you guys think it's futile to try and get another ECU, and that I should start going down the checklist, starting with the fuel system?

IBGREEZY

Thank you Yamae-San. I finally figured out the problem to all my starting issues, it was a clogged third cat. It was obviously so clogged, it was preventing exhaust flow completely causing the car to start once and then die and not start for the remainder of the day. We at ClubLexus are grateful to have you as a contributing member of our community. Not many would invest the time that you have into helping others troubleshoot their cars. Domo arigato Yamae-San

bdazzler

Trying to solve an issue w/ an older Lexus, 1994 LS 400. Problem code said the issue was w/ speed sensor #1 which I replaced. Not shifting into overdrive, cruise control doesn't work. Some have said it might be a problem with speedometer/odometer but found this thread through a search. Searched within the thread but didn't see overdrive issue being related. Has anyone solved same/similar problem as mine by changing capacitors?

Thanks in advance for reading and/or responding...

Yamae

,
Thanks for the update and congratulations on your success to figure out the root cause, IBGREEZY.
I'm sure your LS400 now runs very well.

dlm728

Excellent post! Our 99 ES 300 exhibits some of the listed symptoms. I have changed 100's of caps, but never in a car. I became a monitor repairman at Zenith in 1980. I will definitely ck out the board. Thanks again.

dlm728

Great post. Our ES 300 exhibits strange symptoms. Anything particular to 99 ES 300 ECU?

dlm728

Are 99 ES 300's ECU's at risk?

timmy0tool

iTrader: (7)

to answer your question, yes all models are at risk. though it seems toyota has retrofitted the newer 98-up cars with better capacitors but only time will tell if they need replacing. it also depends if you live in humid climates.

JohnEd

iTrader: (1)

I was an ET when it was tubes and transistors. I am now 72 and down to one eye that doesn't do close work very well anymore. I thought I could do this cap replacement project but I was wrong. I replaced two caps with some difficulty but a third gave me fits and I tacked the new cap onto the old cap's leads. In short.....the board is OK and I have thrown in the towel. I have all the hi quality caps in hand plus extras.

Where can I send this ECU to have the remaining caps replaced? The post is 64 pagers long and I am going blind looking for a contact.

My original problem was it went into limp mode a couple times and just stalled/quit once. All this was reported to me by Wifey.

I live in Eugene, Orygun. Last thing I read years ago was that there was a shop in "Georgia" that did repairs.


Thanks for your help......I need it. 1993 SC 400, 160K miles. Original ECU 541 915 0832 jegrabe@gmail.com

Thank you,

John

golfindude

HI Yamae and all,
My 2004 GX470 is currently dying while at idle randomly and will currently not start; reading this thread makes me think I may have this ECU issue.

Here's the thread I posted in the GX470; does this sound like it may be the same thing? If so, are the CAPS on the GX ECU the same as the LS? The car is currently at a local shop where they're trying to track down the problem - I'm trying to help... Thanks for any thoughts or guidance you might have.

GX forum link: https://www.clublexus.com/forums/gx-...tart-help.html