Hi guys,

My LS400 has a hickup problem.
It occurs when I drive on the highway with a certain speed and then accellerate more.

The hickup feels like a complete ignition cycle is interrupted, but after it happened the engine still runs silky smooth.
It also sometimes occurs like a low frequency "purr".

I read several posts about LS400 engines with hickups and I already tried using 2 bottles of fuel system (injector) cleaner.
This made the engine run a little bit better, but the hickups didn't dissapear.

I have replaced spark plugs and ignition wires about a month ago, because the engine was running on 7 cylinders, this is now fixed.

I also read about capacitors in the ECU.
As I am an electronic engineer I know about capacitors being the weakest electronic component and I already replaced several in my dashboard.
What do you guys think about replacing the capacitors in the ECU as well?
Or is my "Sexy Lexy" having a different problem?

Thanks!!

 

Your car may be experiencing other problems other than the ECU. I have talked to people with bad ECUs and the problems they have experienced were all over the place and usually very random. If you are comfortable with doing the work, I would say check it out. What happens is the capacitors begin to leak onto the board and you know why that is bad. A good throttle body cleaning and a new fuel filter might do you some good. Check out this site. http://www.lexls.com/
Cleaning the throttle body and new fuel filter improved my car.

 

Ok, I will try to clean the throttle house.
The problem is, however, that I was not able to find the gasket for it in Europe, which means that I have to clean it in the still mounted position.

For the ECU, can you (or anybody else) tell me where the ECU is located and how I can remove it?

 

First off, welcome to CL. The ECU is mounted on the underside of the lower panel under the glove compartment. A couple screws and that pops right off and then 3 nuts and the ECU is in your hand. If you can't find the TB gasket just get a small sheet of gasket material and make your own.

 

Thanks!

I think I have seen the ECU when trying to change the interior filter.
I will take a look at it soon!