Low Idle

[kamszii]

Hi everyone

I need help

I just started my lexus ls400 mk2 1993 after about 5months

I made sure everything was all good before starting

It oil water etc.

Using a Battery booster i turned the key and started but soon as i let go of the throttle it turned off i tried it again and again after 3rd time i kept my foot on the throttle and then slowly removed my foot and it was idleing around 350 rpm

Why is it idleing so low?

And also when i put it in reverse it doesnt really move until i touch the throttle this is because of the low idle why is it idleing very low?

New to this by the way

Thanks for any help kam.

[ambermarine]

Hi everyone

I need help

I just started my lexus ls400 mk2 1993 after about 5months

I made sure everything was all good before starting

It oil water etc.

Using a battery booster i turned the key and started but soon as i let go of the throttle it turned off i tried it again and again after 3rd time i kept my foot on the throttle and then slowly removed my foot and it was idleing around 350 rpm

Why is it idleing so low?

And also when i put it in reverse it doesnt really move until i touch the throttle this is because of the low idle why is it idleing very low?

New to this by the way

Thanks for any help kam.

It sounds like the Battery was flat and you are running on the power from the Alternator which is probably running a host of other electrics in the car.

Let the car run for a good couple of hours preferably by running to your mother in law 25 miles away and back and do not use any services in the car Radio A/c etc let the Battery take a decent charge.

The car is not supposed to move until you use the throttle so there is nothing wrong there .

Perhaps you are not used to driving Automatic gearbox cars and if not they take a bit of getting used to.

I would never use a Battery booster on any car that as electronic engine management ,always charge the Battery and let the cars electronics decide what is best for the system.

[kamszii]

I wouldnt have thought that it would be the Battery i asumed it could be the accelerator linkage :(

[ambermarine]

I wouldnt have thought that it would be the battery i asumed it could be the accelerator linkage :(

Kamsil

When trying to identify the problem it is always the norm to eliminate the obvious potential faults.

You mention a standing period of 5 months and that to me screams dead Battery,the car will start on a Battery boost but unless there is sufficient power in the Battery to run the electrics on the engine and ecu it will not function properly because the power needed to run the engine is being supplied from the alternator and that is trying in turn to charge up the Battery.

These cars are sophisticated in their engine management and throttle linkage is not the same as on a conventional carburettor.

First of all get a decent Battery and try that then if that is not the problem the next step is to check the tickover speeds from cold start to normal running temprature.

cold start 1200 revs which drops down to 600 on tickover and after a really long run can drop to 500. If non of that happens then you need it looked at.

[steve2006]

As Ambermarine says there are lots of variables involved when starting a car unused for 5 months, was it started at all during this period?, did you put some fresh petrol in the tank as the stuff deteriorates over time? If the Battery was completely flat the ECU will have reset to default and you need to run the car to allow the ECU to relearn it parameters.

As suggested take it for a good run and then if you still have problems with the idle speed let us know and we can go from there.

Common causes are the throttle body needing cleaning along with the IACV, check all your rubber vacuum hoses for damage/splits but do the run 1st before looking for a fault that may be eliminated through use.

I don't know where you live but there have been cases of rodent damage to vehicles left for long periods of time.

I would also make sure the brakes are all free and working correctly before taking the car out on the road, calliper pins seize up during normal use so may have done so when stood for so long.

[beavisrules]

dirty throttle body is the other common ls400 idle problem cause.

[Parthiban]

I had a low idle problem with my IS200 recently, dealer did a throttle body clean and now all is well - worth checking out :)

[kamszii]

Thankyou everyone much appreciated for the help i will start it up tonight and take it for a drive but have to b careful no mot or tax at the moment :(

Ambermarine i will get a new Battery today that looks like £80 to me lol will get back to you thanks again, kam.

[Malc]

Batteries with a 4yr warranty and sufficient power are @£65 usually these days

Malc

[kamszii]

Malc Battery was £70 lol

Lexus started fine perfect rev sound but for some reason my rev needle isnt moving today was fine yesturday

Thankyous :) kam.

[ambermarine]

Malc battery was £70 lol

Lexus started fine perfect rev sound but for some reason my rev needle isnt moving today was fine yesturday

Thankyous :) kam.

Hi Kamzil

Did the rev counter needle work properly five months ago when you last ran the car,I have some reservations as I have already said about using Battery boosters to start the car as they create voltage spikes and some of the electronics especially around the instrument cluster and audio are very prone to being fried.Are there any other electrical faults showing on the instrument cluster such as backlighting and gauges,is the radio working and the A/C.

[kamszii]

Ambermarine everything else is good

The cluster lights stoped working but i fixed those myself for around £10

£6 for soldering kit

Around about £1 for solder wire

And £3 for fuse and postage, fuse was actually 30pence lol

I fixed that around 7-8 months ago it was fine after that

The petol and temp needel are half working if you know what i mean and when u put the car into P R N 2 L it shows on the dash board

But D doesnt show thats about it

Radio ac are fine although the pressure of air comeing out of the vents are not so powerful having the heat or cold on HI Is like having it on LOW on other cars :( she does heat up well though

[steve2006]

If the airflow is low check the pollen filter under the passenger side dash,look for a black plastic box with 2 wing nuts.

Either wash and dry the filters or replace at around £40.00

[kamszii]

Hi steve i washed the filter and its much better now as i was replacing it yesturday i realised there was another one futher down lol thankyou and mine was a white box :)

[steve2006]

You're welcome I did the same thing when I first did mine,that's why I said "filters" in my post,glad it has helped you.

I don't know how you did yours but I washed mine in a bowl of soapy water,shaking them in the water then ran my finger down each louvre both sides to remove the dust trapped in them.Rinse a few times in plain water until it is clear.I put mine on top of a radiator to dry then when dry sprayed some febreeze or the like on them.

[kamszii]

I just ran my fingers down them with hot water took long enough to dry lol

Thanks again steve

[LS Jasper]

Interesting - I have been trying to resolve my low pressure / cold air at low revs heater problem. I did change the pollen filter six months ago but not checked since. Could there also be blockages in that area that would restrict air flow? Will go and check now.

Jim