Lamba Sensor

[pegs]

Hi there paul here,

Not sure if anyone can help me, but have recently purchased a lexus is300 le, lovely car good miles great condition but i'm having problems with start up!! have been advised that one of the problems that could lead to this is lamba sensors?? does anyone know what the resistance for the lamba sonsors should be or what is required of them. On tick over it shows 0.75 on 2, 0.65 on 1 & on the other its 0.000. Can only but assume that the one showing 0.00 is the dead one?. Please can someone help it would be much appreciated.

[steve2006]

Hello and welcome to the LOC.

Is the engine management light on?

Have you had the OBDII codes read for active or stored codes?

When you say start up problems is this when cold starting?

Any other running problems?

The O2 sensors cannot be accurately checked by simply measuring the voltage since most digital multimeters cannot react to voltage changes fast enough.

If you know someone who has one a scope this is the best way of checking that the output is at the correct level and the switching frequency is also correct

Sorry for so many questions but the more information you provide the more accurate the help.

[pegs]

hi steve had a mate of mine plug in his snapon diags no fort codes but bank 2 sensor 2 was reading 00.00 where as the others where all giveing a reading the start up problem is some times it starts 1st time and others times it cranks over for about 10 seconds then fires up but smells of petrol as if was flooded and when its warmed up its slightly lumpy but performs perfectley is that any help this also happens in any weather please help.

[steve2006]

Check your crankshaft position sensor and wiring to it, located near to the crankshaft pulley, they have a habit of becoming intermittent.

If there is no signal from it there will be no spark at the plugs, the fact you can smell fuel would suggest that is being injected but not ignited possible due to the above reason.

Although I am suprised no fault code related to the CPS has flagged up.

I take it the coils and plugs are all in good order?

[ColinBarber]

The O2 sensors really don't do anything until the engine is warm. Certainly don't have anything to do with starting.

A reading of 0.00 is common on the downstream sensors until heated up. If there was a major problem with the O2 sensors then the CEL would be on.

I would check the plugs first, to make sure they are the correct ones for the engine.

[pegs]

thank you for yor advice ive had plugs change by lexus ive been told now it could be a faulty ecu any idears if you can help most greatful.

[pegs]

hi steve crank sensor fine mate back to the drawing board if you can help most greatful.

[ColinBarber]

worth cleaning the throttle body and MAF sensor. Check out the fuel injectors, ultrasonic cleaning.