A few days ago my check engine light came on (with the Trac off light as well needless to say) and my 92 sc300 with 90k started to idle @ around 2k rpm. There is a strong gas or carbon smell coming from exhaust (some light black smoke) and I have no power. If I attempt to accelerate the car will bog out. I wouldnt be so worried if I could scan the problem BUT the car is not pulling any codes. I checked myself and so did my mechanic. He says its the computer (ECM). I know or should I say hope thats not the case. Any suggestions?? I need help fellas!

By the way.. I know it could be a lot of things like the MAF, o2 sensors, or TPS but how do I find out which one with no codes??!!

Thanks in advance guys.

 

did you try simply doing the paperclip trick (I can't remember the terminals off the top of my head)

also, what color was the smoke exactly?

Black is gas (you're running rich)
Blue is oil (not healthy )
White is water or coolant

 

Thanks for the repy..

Yep, I tried the paper clip trick. No luck. the check engine light does not flash.

Its black smoke. Im running rich. Theres a strong gas smell from exhaust.

 

well, if you can't troubleshoot with codes, and you're running rich, it could be O2 sensors.

but that's speculation.

 

Are all cylinders firing??

 

Nope.. all cyl. are firing.

I spoke to my old mechanic today (who deals with Lexus only) and he knew exactly what I was talking about. He said it could be that my Traction Control is malfunctioning or my fuel pump ECU is shot. He mentioned the O2 sensor but he doesnt think thats it cause of the high idle. Car goes to him tomorrow.

Advice for the day... Only deal with mechanics that know Lexus engines.

The dude that was originally looking at my car had no clue. This guy was asking me , "Did you find out what the problem could be?" HUH!! What an idiot. Never agian.

 

Let us know what it turns out to be. The info could help others down the line. Besides, I'm very curious!

 

Hmm... The first mechanic actually knew what he was talking about. It was the ECM. I lucked out and got one from the junk yard for $150. The first place I went to just happened to have a 92. As soon as we put it in the computer started to communicate with the scanner. The car has so much more power now. But theres a problem.. My air bag light is on now and it wont reset and I'm not getting any codes saying its faulty. If its not one thing its another. Gonna do a search now.