'99 Gs 400 Water Temp Sensor

[Swedishe]

Hey guys,

I bought a '99 GS 400 earlier this year. I am experiencing the following symptoms:

- On a cold start, engine will always turn over fine, rev up to around 1100rpm, then intermittently stall. A light step on the gas pedal for 3-4sec when starting usually solves the problem. It's confusing, though, as sometimes the engine will idle up fine and not stall on a cold start;

- When engine is warm, it never stalls when starting, but rpms usually drop to the 100-200 range before settling out at around 500;

- Engine seems to run rough at idle. Less noticeable when engine is fully warm.

My uncle, Reg Riemer (some of you may know him... he is the owner of RCTS Canada), suggested it may be the Water Temp Sensor. Does anyone have any ideas? Where abouts is this sensor on the engine, and can I replace it myself? Any guidence on how to replace this part myself would be greatly appreciated. I am not willing at this point to spring the $700 Lexus quoted me for the two-part service manual, either.

Thanks!