The "caps" that they are referring to are the cylindrical capacitors inside the ecu. Once you open it, it'll be obvious if they're bad. (Most of the time they'll be leaking some goey material)

But when my ecu had this problem, I just replaced the entire unit and my problems went away. I don't think it was the capacitors because they didn't look bad and after changing them there wasn't a big difference either.

So I doubt its the capacitors, it is most likely some circuitry that went bad.

Here's a link to my thread:
https://www.clublexus.com/forums/per...mely-rich.html

 

thanks for the reply. after thinking about "caps" i figured they were talking about capacitors since we were talking about a circuit board . im going to open the one in the car just to see if i can see anything. if not then ill put the motor back together and replace it with my other ecu to see if that fixes the problem.

 

bad ecu its done trashed. nothing u can do about it except get another one

 

hi guys --- I have the same issue -- white smoke coming from exhaust and major fuel loss with gas in the oil -- plus running horrible. I was informed by some that it was a blown head gasket and/or warped head. I already had the back head off and after planing and a valve job, there is ticking from the back head and some smoke coming from the back of the engine -- ?? -- not sure about this --- maybe needed a thicker head gasket after the head plaing ??? -- any insights here? Also, the mechanics indicated compression is ok -- hence not a blown head gasket. Plus, if it was a blown head gasket, the oil would appear like chocolate milk on teh dipstick --- correct?

From my research, my gut feeling is that it is either a "stuck open" fuel injector and/or a bad ECU. Since I am an EE, I'm going to open the ECU and see what I find. I have spent way too much money listening to "experts" and am desperately trying to fix the car myself this time. I plan on pulling the ECU out and checking it out tomorrow AM. I'll let you know what I find.

BTW -- I did get previously get the codes by shorting pins E1 and TE1 on the diag port and obtained a 24 (IAT sensor) and 32 (Airflow meter) -- via flashing MIL light. Upon further research, I found that one of the pins on the MAF sensor was pushed back. Repaired the connector by pushing the wire back into the connector. Still need to verify Intake Air Temp sensor functionality -- any insights from the experts out there? The MIL is not on and no codes at this time.

On the same vehicle, it is overheating. Lower radiator hose is not hot while the top one is --- suspect stuck closed thermostat and/or clogged radiator. Will update you all on this as well.

Again, there appears to be multiple issues with this vehicle. (heavy sigh)

 

I found a replacement ECU for $50 for my 92 ES300 --- Should I give it a try? After examining my ECU and hearing back from some experts -- I'll decide the next step . . . I don't want to be married to this job -- -- . Thanks!

 

It's time you took it for repair coz a big problem is just paving it's way. For the forgotten thread I think typing some keywords in google should help. Good Luck!

 

same problem on cylinder 5 right now, when i turn the key on the injector opens up without it even running.

 

i am having the same problem currently....i change my spark plugs, spark plugs wires, distributor, distributor cap, etc.....the car use to smoke a little then it would disappear, there is a high smell of gas when idleing....also the idle would drop up and down and the whole car would vibrate....this happen for 3 days straight...today i started the car and there was thick white smoke coming out the exhaust constantly....again high smell o gas and vibration......is this an ecu going bad / is bad or head gasket going bad??...

 

Before you go messing with things that don't need to be replace. Get an ECU and swap it 1ST.>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<

 

i just purchase a 1993 ecu from user nova .....hopefully this resolve the problem....i will update _when i put the ecu on ...

 

im having similar problems ...i change my plugs , plug wires, distributor , and dist. cap...it was still smoking (white smoke).,....i then bought another ecu and put it on ......it wasnt smoking as bad as before but when u step on the gas really hard or at high rpm it will smoke alot.....what do you guys think another bad ecu or stuck injectors ??? etc

 

hey guys......

im happy to have found this thread.......... let me give you guys a run down of my car....

when i bought it.... the computer was throwing codes relating to the O2 sensors...
i replaced O2 sensors but the coputer was still throwing those codes.

once the ignition was turned on, u could hear the hissing of fuel running in the engine.... i was told that the ecu needs to be replaced

replaced ecu..... what do u know...... computer wasnt throwing any more codes......... car was still running a bit dogy...you could still hear the hissing of fuel !!!

checked the distributor brush and it was seriously damaged and needed to be replaced.... car ran way better after it was replaced.....


up to this point..... absolutely no smoke.... car was running slightly rich and you could still hear the hissing of fuel........ (even after injectors were changed !! )


ok...... so i decided to give the car a full service and here is a run down of all that was changed/added

- distributor cap
- iridium spark plug
- spark plug cables
- engine oil
- oil filter
- injector seals and o-rings
- air flow meter
- ignition coils (both that sit on left side of engine bay)
- PCV valve (that sits on right rocker cover (facing the engine))
- oil catch tanks were added
- air intake was replaced with free flow intake + filter (this was replaced long before servicing the car)


the whole intake manifold was lifted to get to the injectors to replace em and lifted couple more times to replace injectors n replace seals and o-rings (previous ones were damaged n gas was spraying from em so they were replaced asap)

i tried to replace all vacuum lines as best as possible following the diagram in the engine bay... only ones im not sure about are those for the EGR......


so even after swapping around ecu...... i get teh same result !!
think white smoke with strong gas smell..... of course when the car is reved, the cloud gets thicker..... (ohh.. when u try n rev the car...rpm drops like its gonna shut of before picking up)

I know its not my head gasket, i know my cylinder walls aint warped or cracked because the car has been parked.... it wasn't being driven any at all.......

could both ECUs have gone bad ??
could it be a timing issue......



im wondering if i should put back old spark plug cables etc.....

and as for the hissing of fuel... that continues ! regardless of either ecu i put in there....

could it be both ECU's are bad??? i wonder...... the second ecu i got.. i had started car n driven it in the parking lot once with no issues

 

^^ That's a lot of things at once. I'm not as expert as some here but I did go through a vaguely similar experience:

https://www.clublexus.com/forums/per...condition.html

Do you have an SC300 or SC400?

You've already done many fixes. The only things it seems you haven't done is outright installed remanufactured injectors (but hard starting in addition to the smoke is usually what makes that necessary)... and installing a *rebuilt* ECU.

Yes, it is entirely possible that the 2nd ECU you installed still has issues of its own. The only way to be sure these days, given the age of all of these computers, is to send them out to have the capacitors and injector drivers replaced. And they have to be very specific capacitors. By now, most of us should be aware of the need to get our ECU's rebuilt. Toyota/Lexus used a questionable capacitor in their ECU's between 1985(?) and 2000 or so that did very well... until it leaked. Thankfully, there is a common way to get it fixed.

For reference:
https://www.clublexus.com/forums/ls-...capacitor.html

Have you tried sending your other ECU in to Tanin Auto? Your side profile says Kingston so if that's in the USA it wouldn't be that much turn around time.

And no, don't reinstall the old spark plug cables. The newer, the better.

 

To be honest... Lol.. I was using Google N replied directly to this thread N later realized it's fir sc300..

I'm fact i own a 93 gs300.. I've since posted it on that thread....

I'm in fact looking for another ecu and im located in Kingston, Jamaica...

So it might be kinda expensive for me to send my ecu to have it rebuilt but if that's what I have to do them I have to do that...

Car was running pretty much ok prior to all the changes with the second ecu..
But could disconnecting /reconnecting the battery cause the Ecu to go bad... Lol...

I had put back old cables N plugs but same result so when I get new or rebuilt ecu, I will just install newer items as well...

 

Ahh, yes! I should have realized-- Kingston!

Good that you moved to the other correct forum but I'll reply here for the moment. Your GS300 is very substantially similar to the SC in regards to this issue.

Well... I don't personally know of any specialist shops in Jamaica... or even in the Bahamas. There might be but you want someone who knows what they are doing and who will use the correct capacitors for reconditioning. They're very specific types and come direct from Japan.

I'd talk to Tanin and see what the options are, yes. I am sure they can do international. Or if this is a US-spec model you have they can probably match the ECU number with a unit they can obtain and rebuilt it and ship to you in Kingston. It would involve the cost of another used ECU but would involve only one way shipping. They should be able to do this easily unless you've got the rarest of SC ECU's. I honestly don't know how the cost would work out but it's a thought.

The age of these ECU's means they will all be affected by leaking capacitors be they USDM, JDM or European. So it's more than likely many of us will need reconditioned capacitors and drivers eventually as time marches on.

Good luck, skytechja!