LS400 Hard to start

[Tobin]

Hi folks, I'm a newbie to the forum and new to Lexus.

Just made the move a couple of months ago from 80's Merc to 90's LS. After a lot of reading I decided the 93 LS400 was the one for me, then I spent some time waiting for an original example to come up. Found one! A 1000km round trip to pick it up but well worth it and a very nice drive home.

Once home I stored it in a garage for about six weeks while getting the old Merc ready for sale. When I next went to start it there was a lot of hesitation as it struggled to crank over. I figured the battery was a bit flat after six weeks of non-use. Half an hour later I started it again. This time it started instantly. Next day it struggled to start again.

So, here's what happens:

If the car is cold or hasn't been run in the last hour then it struggles to start. For the first few rotations the starter motor barely manages to turn it over, then it seems to ease up a bit and cranks ok, but still doesn't start yet.  After a few more seconds of cranking it starts. When it does start there is no rough idle or problems of any kind. It idles smoothly and drives normally. If I then turn it off and start again it starts fine. It's only when it's been sitting for roughly an hour or more that it struggles to start.

The worrying part is that unlike a typical flat battery scenario where the engine initially cranks but subsequent cranks get weaker, this is the other way around; it struggles most on the first few rotations and then frees up. I had a Merc that was behaving similarly and I soon discovered it had a blown head gasket that meant the engine was trying to compress water on the first few rotations. I'm hoping this is not the case with the Lexus ($$$$$$)

The coolant looks normal. No bubbles. The oil looks normal. No blow-by. No smoke. No overheating. It drove fine on the 500km journey home and there's nothing else to indicate there is an issue. It's done 240000 with good service history (was dealer-principal's car).

Any ideas? Please tell me it's not a head-gasket!

[Moarpower]

Not likely a gasket. It could be the starter motor becoming a bit old. Also have someone test,m or use a different battery. Ive had many a battery show these symptoms whilst I was blaming other parts. 

Its not fuel, as that wouldn't stop it from cranking, just starting. So certainly test the ignition system, chech the wiring and fuzes, battery and ensure there is no power steering leak above the alternator..My bet is battery or starter. 

[Tobin]

Well this is embarrassing. But good news for me. Thanks Moarpower, you were right, just a stuffed battery. The odd cranking behaviour made me assume something more complicated, but checking while cold the battery was 10.5 volts. Amazing it started at all really, though the battery was huge, over spec-d for the car, but nevertheless stuffed from sitting unused with a crude trickle-charger cooking it for months (car was in storage for ages before I bought it) Thanks for the reply!

[Moarpower]

Thats great news!!