compx

Hey lexktek1, I have read and read and came across a thread where you helped a fellow fan address his ecu "goo" issue. I bought a 1994 lexus LS400 3 weeks and since day 3 it has exhibited these same symptoms: Stalling, dies without assistance from throttle, jerks/hesitates, check engine light flashing on and off, and the only flash code I got was 28 which from what I understand is an O2 sensor.

Each thread that I read has said to replace the caps.

I am not exactly sure what these are? I pulled the ECU out and have snapped some pics here, mostly because I was totally expecting to see goo, and what i see is no goo. Is it possible that the caps are still the culprit but I have caught them prior to the leak out?

To date I have replaced Water temp sensor, plugs and the wires.

Something else too, Day 3 these symptoms started, then when the car was cold it would be fine, in fact it drove for 1 whole 7 day period perfectly, then this last saturday it resurfaced and has not corrected itself when cold.

I pulled service record from friend who works at lexus dealer, according to that the previous owner reported the following on 3/16/2011 with 172,576 miles: CUSTMER STATES VEHICLE WILL INTERMITTANTLY HAVE EXTREME LOSS OF POWER,ACTS
LIKE IT IS STARVING FOR FUEL,MISSING OUT LET SIT FOR A WHILE AND IT WILL BE FINE-ADVISE ~|~ ~|~NO REPAIRS DONE.

I took it in almost 7 months and 800 miles later with same description.

SkulCracka

lextek1 is no longer posting here. sorry. but your caps look fine.

are you sure you replaced the right temp sensor the big one on the block not the small one. also if it sits and then runs fine again could be something as simple as the fuel filter.

http://www.lexls.com/tutorials/intro/codereading.html

im getting code 21 which is left o2 go a good deal from rockauto.com on them.

besides the fuel filter check air filter i know small things. but do that. then do a seafoam and throttle body cleaning. this helped my car alot when i first got it a few weeks ago.

have not chnage out the o2 yet but will soon along with the temp sender sensor.



the green one is the right one. the little one in the back is for your cluster gage.

compx

Yes have done seafoam, yes that was the temp sensor i replaced, fuel filter has already been done by previous owner, took car into local shop prior to dealer, they checked fuel pressure reg, pump, pressure at injectors..fuel system is fine.

Not sure where to go with this then.

PureDrifter

iTrader: (10)

did you check for spark in all 8 cyl....? almost sounds like a coil/ignitor issue.

Yotarip

The caps in question are the brown cylinders with silver tops. Sometimes they will swell and become disfigured when they pop but not always. Mine didn't swell.

Take a close look at the bottom where the leads are soldered to the board. Look for brown/black residue on the lead and solder at the board. The solder ball should be shiney like all the other soldered leads on the board. If a solder ball is dull, it may be a sign of acid corrosion from a cap on it's way out .

compx

Yes I checked those too because those are what I thought everyone was talking about. I see shiny solder, I went ahead and wiped them with q-tip and alcohol just to make sure my eyes weren't
missing any traces and they did not pick up any traces of any residue.

I don't mind replacing these, I kinda figured with all the warnings about it, to go ahead and do it anyway, if nothing else i can at least check them off the list of potential problems. I am fortunate enough to have a Frys here in Indianapolis, so I will go in and see if I can pick a few up since they are cheap and go ahead and replace them this weekend.

I will update in a couple days. Thanks each of you for taking the time to respond.

SkulCracka

^^^^^ what he said.

please tell me you didnt clean the AFM << mass air sensor.

compx

No, no cleaning of the MAF, yes spark / ignition has been checked. Basically everything has been checked which is why I am leaning towards these caps. My only doubt is that the caps are not showing any visible signs of duress. However, not being an EE, I have no idea if they have to prior to breakdown.

Again, going to replace these due to low cost, next up will likely be MAF.

Interesting note, while car is behaving badly, you can remove a plug wire, (each of them one at a time, unplug the MAF) and not notice any difference in the way the car is behaving.

Keep the ideas coming though,

Cheers

trukn1

Same thing as Pure drifter stated, sounds to me as if you have an ignition coil gone bad. My car exhibited some/most of the same symptoms when mine went out. Are you smelling gas when this is happening? I was, at the time, replaced the coils and good as new since.

compx

Yep smell of gas, stuttering, wont keep running, herky jerky when driving.

PureDrifter

iTrader: (10)

how exactly did you check spark? did you pull one spark plug wire from each cylinder with the car idling?

compx

originally took it took mechanic (independent), then to toyota, none could diagnose, tested fuel and spark systems, said all is good. check engine light only threw O2 sensor.

Started reading threads and boards, every time someone has posted up about all these symptoms lextek1 and others yapping up about these caps. so i post up my picks.

compx

just tired of guessing and no one seems to really know. including me. honestly the ecu is a longshot imo.

PureDrifter

iTrader: (10)

so stop guessing, do some troublshooting, and figure it out.

its not like you need any tools to check spark like i told you...

compx

pure drifter,

thank you for your help, however again as i stated, these have already been tested and proved to be still be working fine.

My original post was asking about these caps, now everyone is out pointing fingers in all these other areas that I am satisfied have been diagnosed and not found to be the problem.