Ls430 Slightly Lumpy

[Stu.]

Hi everyone,

I thought i would unlurk as ive searcghed everywhere for months and not really got anywhere lol. Hopefully someone has seen this before.

Ive got a 2002 LS430 with 39K on the clock. No ECU codes are being flagged up.

The engine has always had a little bit of a lump to it. Ie when cold it had a vibe through the cabin which was very sypmathetic, ie come, go , come go.

This is still evident around 2.5k when warm, and during normal driving conditions. Its not a misfire as such, it just feels like a bad fire, or lumpy feeling.

Its been lexus serviced, and all plugs have been changed (which made a big difference- 50% improvement) All the plugs looked clean and in good condition.

I noticed last night with the window open, the engine sounds as though it has a wee bit of a pinking noise when under sudden acceleration. It is slight however.

Any thoughts would be appreciated!

Thanks for your help

Stu

[Haylands]

Hi,

Welcome aboard....

Haven't really got a clue about the lumpyness, but with that very low miles could probably do with a good drive

Mine was owned by an old chap before me and was tight and sluggish, a shot of injector cleaner in the tank and a good blast up the motorway (never going above 70mph...honest officer ) made it smoother faster and more responsive... they give you nearly 300bhp I think we owe it to them to use it!!!

Anyway jusy my 2p worth

Good luck

Pete

[Stu.]

Pete,

I thought exactly the same thing! Ive booted the living daylights out of it and injector cleaned it

Thats why im confused :-0

In fact ill probably do it again tomorrow, lol.

Stu

[jsj24uk]

It might be worth getting the sensors in the exhaust changed. Especially with very low mileage as the might have sooted up. It might also be worth changing the petrol you use to BP Ultimate or the Shell V Power for a while. My LS430 spends most of its life stuck in traffic and then once every three months I take it for a good hard drive for about 300 miles or so. Helps to keep the spiders out the exhaust.

[paul_k]

a wee bit of a pinking noise when under sudden acceleration

Sounds like dodgy fuel.

I run my SC430 on Tesco 99 seems much more responsive on the throttle and convinced I am getting more power.

Paul

[Stu.]

a wee bit of a pinking noise when under sudden acceleration

Sounds like dodgy fuel.

I run my SC430 on Tesco 99 seems much more responsive on the throttle and convinced I am getting more power.

Paul

I tried running it on V-Power today and it is much better.

Ill keep running it on that...then im going to have a look at lambda sensors. The only prob has been a long term one for about 10k miles or so.

Just not really sure what it is!

Stu