Hi,

i am having trouble getting my 92 sc400 fixed.
the engine starts poorly and most of the times runs very bad.
no power, misfire back through the intake. the airbox intake actually opens by the backfire.
when i bought it was only doing 60-70mph and accelarating very slow, starting in third gear or so.
but sometimes it just runs fine without any trouble. when i let her run for like 15 min she starts running bad out of the sudden.
I did the 60000 miles service, nothing changed, the engine ecu was checked and is fine also.
My guess right now is the fuel pump?
The car had water inside the cabin, running down the a pillar from the windscreen, and also in the back from the right rear window. I got those leaks fixed.
any hints?

christian

 

What sounds like the most probable 3 things is 1, the Fuel pump, 2, the MAF, and 3, Spark plugs and wires.
The loss of power sounds like a scenario I had with our GS300 a couple months back. Sounds like a faulty MAF.. and if you did not replace the spark plugs and wires then definitely do that. Or did the 60000 mile service do that as well?

 

The backfiring sounds like timing is off. Pull out your plugs and take a look at all of them as well. You could have a dead cylinder. You can also take a mechanic's stethoscope and listen to all your injectors to see if they are all opening and closing.

 

Hi,

thanks for the answers! I am not driving it till it is not registered yet.
I already did the plugs, today i changed the fuel pump.
Still the same problem.
sometimes it runs just fine. The trac and the engine light sometimes go on. the engine light only glows a bit sometimes. there are no error codes when i connect the two pins TE1 and E1.
The previous owner changed the fuel filter with a garden hose!!!!
I already put a filter back in. The fuel tank looked very clean when I changed the fuel pump today!
still no clue!!!!

Christian

 

Did you change the wires as well? and did you rule out the MAF?

 

Hi,

i did try the maf from our ls400, didn't change anything.
I did not change the wires yet.
what about the cats?
the exhaust temp seems to be very high.

chris

 

Change the wires soon before anything else...could of melted some of them, they are around $50.

 

i will try the wires from the ls, but they looked fine while changing the sparks!

 

You would know for sure if you bought brand new parts specifically for your SC400. I would never interchange parts with Lexus vehicles, even if it might be adequate. Though, I understand with the MAF... $700 part!
Just noticed, How's Germany?

 

hi,

just want to inform you that i solved the problem.
the engine ecu was broken.
it is rebuilt and works perfect.

christian

 

That was my first educated guess also. Glad you got it fixed..

 

LS400's go through ECU's. Glad you got that thing fixed.