Lexus Other

I have a 1990 lexus ls400, 160k, v8. The problem that I am having is that, every couple of weeks, it chooses not to start. I replaced the battery and the alternator. When I try to start it, at times, it will not turn over (doesn't make a sound). I can have it jumped and it will crank. It also takes about 2-3 seconds for it to crank when it does. I also changed the spark plugs. A friend told me that it was the starter that needed to be replaced. I was going to do so but I cannot find its location. HELP! Is this a starter malfunction and, if it is, where is it located in this particular car? I would be VERY greatful for any amount of assistance. Thank You :
October 7, 2007.

Going by what I see in the mitchell books, unless you are a very good mechanic, have a shop do it. This model requires a lot of engine dissasembly to replace...and it may not even be the problem! The security system, neutral saftey switch, relays or wiring could be the problem.

All these parts must come off to get at the starter!

Oct 7, 2007.
Starter is in the " v" of the engine. Yes I would have it checked by someone familiar with this model before going any further.

Oct 10, 2007.