Guys I've owned my Lexus SC300 for 2 years and for the past year she hasn't worked correctly. Problem number 1 is that my car sputters and smokes extremely bad (smells likes paint). I have recently changed out spark plugs and Injectors and for some reason a brand new battery dies in my SC in a realistic 3 weeks. A mechanic told me my ECU was burnt out. What do you guys think my problem is? Please help me if you can.:sad

 

1. Turn off the bold, we can read it just fine without it.

2. What year is your SC? Mileage?

3. Exact symptoms?

4. Any CEL (Check Engine Lights)?

5. Either your alternator is bad or else something is taking power and draining your car's battery. Do you have anything aftermarket on there?

The more information you give, the easier it is to diagnose a problem.

Jonny

 

if the battery is dying you may want to look at your alternator if thats going bad on you. im not 100% sure on the stuttering but clean her out with some seafoam while your at it to help things out

 

Guys, I'm sorry about the Bold print. My SC300 is a 1992 and she has 125,000 miles. There is no check engine light on anymore. A mechanic told me my ECU was fried and that was causing the sputtering and all of the smoking. When I accelerate my car just sputters. So far I installed an Injen Intake system and JIC Magic Exhaust system. The exhaust smoke has a real rich paint thinner smell. It you guys need anymore information please let me know. Thank you again for the help

 

Well when i installed my safcII I had to splice my airflow wire that goes from the maf to the ecu but for some reason when I started my car It would sputter and smell really bad of gas from the exhaust. I thought I had wrecked my car. but I found that one of my wire splices had not completely connected. so the ecu wasnt being able to read the airflo. the symptoms seem similiar so it leads me to say that you have a bad ecu like the mechanic suggested.

 

So my ECU is the problem. Thank you for the information. I think that my alternator is the reason I go through so many batteries. Who would you guys reccomend me getting an ECU from?

 

also to add if your car is having these problems and your car doesnt throw a CEL then the ECU must not be working properly. cause mine did but after the fix I just reset the ecu and now all is good.

 

Thank you for the feedback. How do I get to my ECU? Where is it located?

 

Under the carpet on the passenger side. You will need a 10mm socket to unplug the harrness. (you can use a screwdriver but there in tight so you might strip it)

 

Thank you. Will I have to remove the seat? Is there another way of getting to it?

 

No you don't. Just peel back the carpet where the passenger would put his feet and you will be right there. Disconnect the 3 plugs and use a 10mm socket or screwdriver to remove the screw. Put the new one in. Probably a 10 minute job

There were some people selling used ECU's in the classifieds.

Good Luck,
Jonny

 

Make sure you unplug the negative battery cable before messing with the ecu.

Paint thinner smells? Neverheard that unless he's running extremely rich perhaps?

What color smoke are you seeing man????

Also- if you have the means, get a volt meter, with the car turned off the battery should read 12V, now with the car running, what kinda volts are you seeing, with no accessories on at all.


Ryan-

 

could it be the maf?.. if the maf isnt working.. it wouldnt send the airflow info to the ecu?...

 

OK lets me start by saying thank you all for the information. The color of the smoke coming out of my exhaust look white with a blue tint. I looked at my ECU last night and it says that its a rebuild. I think this is the problem. i will also look at getting a new MAF. How can you test your MAF?

 

when my last sc did that i believe it was related to all the gunk in the intake runner after the egr part, cause it was so gunked up from the previous owner using crappy gas. All the stuff burning up in there made this very distinct smell, kind of like unburnt fuel, but kinda worse. I vote for seafoam!

Sometimes when people reset their ecu and their car drives terrible is when they realize there maf is bad. Before you reset it your car can use its stored data to kind of correct any wierd maf signals and adjust.
once you reset it relearns from the maf and if its bad your car will run bad.

so if you havent reset the ecu in a long time, drive it, reset it, and see if there are any drastic differences when it is in closed loop again.