Idle Speed

[lutonmatt]

what sould the idle speed be on a mk3 ls400 as i have only had mine about a month but when is cold it idles about 1700-2000 when its warm its ok it goes down to about 500 but i have never had a car that idles so fast i know its a big engine but it still seems fast

matt

[steve2006]

what sould the idle speed be on a mk3 ls400 as i have only had mine about a month but when is cold it idles about 1700-2000 when its warm its ok it goes down to about 500 but i have never had a car that idles so fast i know its a big engine but it still seems fast

matt

Mines a Mk2 and I find cold start tickover to be around 1200-1500 rpm and I think the correct warm idle speed is 650 rpm.

[JellyBean]

My '96 Mk3 idles at 1000 rev/min when cold. Makes for interesting progress when moving from a standstill in icy conditions, when car does wheelspin whenever one lets off the brake.

[simontaylor]

My 95 Mk III idles at 1800 to start with, a handfull in the snow, and when warn drops progressivly down to 600. But 1800 does seem a lot, probably somne valve blocked or needs cleaning, but I have cleaned the throttle body a while ago.

[Syd Lambton]

what sould the idle speed be on a mk3 ls400 as i have only had mine about a month but when is cold it idles about 1700-2000 when its warm its ok it goes down to about 500 but i have never had a car that idles so fast i know its a big engine but it still seems fast

matt

my 1996 cold 1000rpm hot 200rpm and not lumpy ie smooth as a nut

[toffla]

what sould the idle speed be on a mk3 ls400 as i have only had mine about a month but when is cold it idles about 1700-2000 when its warm its ok it goes down to about 500 but i have never had a car that idles so fast i know its a big engine but it still seems fast

matt

my 1996 cold 1000rpm hot 200rpm and not lumpy ie smooth as a nut

my 96 the same as yours, but mine at hot is more like 300rpm, very very quite

[cleverdick]

what sould the idle speed be on a mk3 ls400 as i have only had mine about a month but when is cold it idles about 1700-2000 when its warm its ok it goes down to about 500 but i have never had a car that idles so fast i know its a big engine but it still seems fast

matt

Have you checked the TPS?

[lutonmatt]

no not yet but now i have been using it it seems to go down but it does rise again i might have a clean about under the bonnet and service it as i think its been standing for a bit

[moriwaki]

My MK 3 starts at a high sounding 1200 and then gradually settles to around 300 after a few minutes...a friend also has a mk 3 and his car occasionally cold starts every day at around 1800...very awkward !...he found if he disconnects the Battery the idle seems to re-set to the 1200 ish...then its OK for a few weeks...then repeats...Good Luck.

[Raven]

Hi,

My 98 LS400 idles at about 600rpm hot or cold. Cold starting is difficult- the engine fires well, then as the revs drop, the engine dies. This happens three or four times in a row, then finally the engine management or whatever catches the engine just before the revs get to zero, and it climbs to a nice 600. Touching the pedal whilst starting solves this, but shouldn't be necessary.

This isn't a major problem at the moment but in the winter I'm worried it won't start very well if its aiming for warm idle even when its cold. Only bought the car very recently so don't know how it behaved last winter!

Anyone had a simlar problem?

Rob

[lutonmatt]

my mk3 still starts high but i jsut have not looked had it let but the other day when i stoped at a roundabout it stoped and then it started no prob

i think all you have to do is clean the trottle body and sracp all the carbon off

[ROYT]

1200 cold for me, rapidly falling to around 500......MK2 '94

[Syd Lambton]

what sould the idle speed be on a mk3 ls400 as i have only had mine about a month but when is cold it idles about 1700-2000 when its warm its ok it goes down to about 500 but i have never had a car that idles so fast i know its a big engine but it still seems fast

matt

Hi Matt

My MK 3 starts at a high 1200 and then gradually settles to around 300 after a few minutes...

Syd

[lutonmatt]

my one sits at about 1500 ish when cold then drops when warm to about 400 ish i do not mind it but putting it in gear when cold it jerks quite a bit but itts the only thing about a auto

[meridian]

Hi, I've had similar problems recently with my 1995 Mk3. Engine always ticked over at 1,100 rpm when cold going down to about 300 rpm when at running temperature. For the last 5 - 6 weeks it started ticking over at 1,700 rpm when cold. I put this down to the recent cold weather but last Sunday, whilst driving in the rain, I put on the wipers and the engine began to cut out! (and the wipers would not function). I checked the wiper fuse (20A) and it had blown. Replaced it with a new fuse and it blew immediately. Left the car overnight and tried another fuse the next day and the wipers worked fine AND the cold idle speed was down to 1,100 rpm again. Surely a coincidence as I can't see how this could be affected by malfunctioning wind screen wipers.

The engine idled at 1,100 rpm when cold for almost a week and suddenly, yesterday morning, it went back up to 1,700 rpm.

I am totally baffled by this. The fuel consumption has obviously increased considerably and I don't know what to do to resolve this other than to take it to a Lexus main dealer and get a diagnostic test done (which will no doubt be expensive and may be difficult to detect as the problem seems to be intermittant).

Any chance it might be a problem with the air flow meter? Any advice welcome.

Cheers guys

Mick

[floggit]

my one sits at about 1500 ish when cold then drops when warm to about 400 ish i do not mind it but putting it in gear when cold it jerks quite a bit but itts the only thing about a auto

Hi matt, i could have written your post myself, mines indentical ... 1500 cold / 400 warm... same for the box too, sweet when warm lol

Cheers steve.

[Glenn007]

Hi Matt

I had a 96 LS400 and it rev'd at 1000 - 1200 cold and 650 when warm. Not sure if it's worth trying to use some injector cleaner, the type you put into your petrol tank! A cheap way to see if it helps, cant do any harm. How many miles are up on yours? 95,000 on mine with FSH.

what sould the idle speed be on a mk3 ls400 as i have only had mine about a month but when is cold it idles about 1700-2000 when its warm its ok it goes down to about 500 but i have never had a car that idles so fast i know its a big engine but it still seems fast

matt