Cold Re-Starting

[Clunkfish]

Hi everyone, a happy New Year to all! :hohoho:

I have recently had a couple of instances of difficulty in re-starting my 1998 Mark IV LS400 in the cold. It has happened when I have started the car (starts first go every time, no problems there), then had to turn the engine off for some reason (e.g. to park the wipers pointing up so I can remove a bit of leaf trapped under one of the blades), then go to restart. The engine cranks just fine but won't fire. If I leave it for more than half an hour or so, it's all back to normal; if I try after 15-20 minutes I can usually get it started but only using lots of loud pedal and with a strong fuel smell around the car; if I try after only 5 minutes then no chance.

Like I say, regular cold starting is fine, it's just this business of re-starting after the engine has already been run for a few seconds. Anyone got any ideas....? (Apart from don't keep turning the engine on and off!)

[ManicMark]

My old one done that I think the cold start device stays full on & then has the same effect as a full choke. i dont know if it doesit on this one my new one as I dont start stop & try & restart from cold.

[ambermarine]

Sounds like the engine is flooding and soaking the plugs this is a common fault on lesser cars but usually unheard of in a Lexus.The fuel is poured in on a cold start and if the engine is allowed to get to a running temprature mode any excess fuel quiclkly evaporates before it soaks the plugs.If the engine is continually using the cold start mode which is controlled via the ECU from a temprature sensor in the engine coolant it will excaberate the problem, because it will continue to soak the plugs ,hence the strong smell of petrol .If you are not getting any problems with normal starting after the engine as been running for a couple of minutes then the foregoing will probably be the answer to your problem.If the problem starts to become frequent there is a fuel management fault get the engine fault code system checked for any held code malfunctions.

[cruisermark]

Sounds like the engine is flooding and soaking the plugs this is a common fault on lesser cars but usually unheard of in a Lexus.The fuel is poured in on a cold start and if the engine is allowed to get to a running temprature mode any excess fuel quiclkly evaporates before it soaks the plugs.If the engine is continually using the cold start mode which is controlled via the ECU through a temprature sensor in the engine coolant it will excaberate the problem, because it will continue to soak the plugs .If you are not getting any problems with normal starting after the engine as been running for a couple of minutes then the foregoing will probably be the answer to your problem.If the problem starts to be frequent there is a fuel management fault get the engine fault code system checked for any held code malfunctions.

very well explained!

[black400]

Sounds like what mu 99 os doing , waiting to get a diagnostic

[Clunkfish]

Sounds like the engine is flooding and soaking the plugs this is a common fault on lesser cars but usually unheard of in a Lexus.The fuel is poured in on a cold start and if the engine is allowed to get to a running temprature mode any excess fuel quiclkly evaporates before it soaks the plugs.If the engine is continually using the cold start mode which is controlled via the ECU through a temprature sensor in the engine coolant it will excaberate the problem, because it will continue to soak the plugs .If you are not getting any problems with normal starting after the engine as been running for a couple of minutes then the foregoing will probably be the answer to your problem.If the problem starts to be frequent there is a fuel management fault get the engine fault code system checked for any held code malfunctions.

Very clear and informative, thank you so much :) :)

[Adam Evans]

My Toyota Sera did this when I was getting off the ferry in Dunkerque a few years back

I switched it on and then got told to turn it off as the queue was not ready to move yet.

30 seconds later I needed to start up and it just wouldn't fire.

But I have a fail safe on the gas system which is if it won't start on petrol for any reason after cranking for 5 seconds and no luck it will automatically start on gas

Anyway I heard the gas solenoids click and it fired up on gas instantly.

I have no idea what it was or why it did that but at least I had the gas system to fall back on.

[jimmy-g]

i had the same problem on my car a few weeks ago,and also happened on another lexus i owned some years ago,started the car run for around 5 to 10 seconds turnd of and woundnt restart,felt like the car was flooded,left for 30 mins then tried again,started after quite a few turns,been alright since,nothing to worrt about,how many times are u going to start a car for 10 sec, or so,turn of and restart,almost never.

[Exdee]

If you flood the engine you need to depress the accelerator while starting the car. This will get rid of the excessive fuel and start the car.

[jimmy-g]

tried it jami,didnt work.

[Malc]

I have had the same problem too, just don't try to re-start so soon after,

It doesn't seem to help to try to de-flood the Lexus, unlike many other cars where that trick often works.

Just a nuance of my Lexus ........ well yours too I guess. I just live with it and try to simply avoid putting the car in that embarrassing situation ... I'm sure it realises deep down it's misbehaving !!! like an errant two year old

Malc

[munday]

Coolant temp sensor, check this link http://www.clublexus.com/forums/ls400/377171-diy-coolant-temperature-sensor-change-pics.html

Easy to check (if you have a multimeter and the right info which i can provide) and easy to replace too

[MNP]

Happy New Year to all.

Have to say that I had a couple of Volvo 850's many years ago, nice cars but both would cause problems if started then stopped again when cold. There was a technical reason for this which escapes me at the moment. It was 10 plus years ago from the Volvo forum! All subsequent cars I have owned I have avoided the issue by at least letting the motor tick over for a few minutes. I try not to use any of my cars or motorbike for really short journeys too, I hop onto my push bike!!!!

All the best for 2014.

Mark.