My Ls400 Stalling While Driving.

[Tiny]

I have had my LS400 for two weeks now, what a great car! But in the last week it has, twice, stalled when I have been going slowly in a line of traffic at lights. Has this happen to anyone before, and if so how do I overcome the problem?

Thank you

[Steve]

does the car feel like its surging.. bouncing when you touch the accelrator?

[Tiny]

No, it just cuts out. With it being so quiet I don't notice until i need to move away.

[Tiny]

On looking at the rev's when I come up to lights, the rev's dip right down to about 400 rpm, then go up to about 800 - 900 rpm and then settle down. If the is a long queue then this can happen two or three times while waiting for the lights. Any ideas??????????????

[Steve]

hmm i sort of have a similar problem but only when i come off the motorway and then come to a stop the car wants to cut out.. but manages to recover...

does not sound as bad as yours though

I am not sure what it is.. but if you find out I would be interested.

[Tiny]

While looking at the othe rpages on this site, I came across this item

http://www.lexusownersclub.co.uk/forum/ind...ST&f=48&t=7325&

I tried it and my car seems to run fine no problems, so heres hoping!

[imtiazhuss1]

Hi, I have the same problem with my 98 LS400 i.e. the car will simply shut down while I am driving. I had the problem sorted for about a week when I replaced the Battery with a new one from Lexus, but now it's stalling again without warning. I have noticed that if some of the electrical devices are used e.g.AC then this usually causes the car to stall. Do you know how you sorted the problem out, as I do not wish to switch off the AC and other functions! :)

[Steve]

hmm this is not the problem where the power sterring fluid leaks into the alternator?? this was a common problem

[imtiazhuss1]

No fluid leaks. I don't know whether it is relays (don't know how to check these as broken fuses can be seen easily) or what. There is obviously a pull on the electrical power when AC and other devices are used. I've checked the new Battery and it is still showing the Green light. It is an intermitent thing. I replaced the old Battery because the stalling was happening a lot while driving. Miraculously, with the new Battery fitted for a week the car did not stall at all, even though all electrical functions were being used. Why now after a week or so?

[ColinBarber]

sounds like an alternator problem. Your new Battery was probably fully charged and has taken a week to discharge.

[imtiazhuss1]

The car's only done 73k miles but I do accept that only short journeys are made each day (10 miles per day!)

[Steve]

has the car ever failed to start because of Battery problem?

[imtiazhuss1]

Yes, on the old Battery. When a stall would happen if I tried to start the car the car would click, click, click but the engine would not start. On the current new Battery which has a green light, the engine starts ok. I've just checked with a Lexus Service dealer who says that the alternator cannot be at fault, as a new Battery will drain within a few hours if not charged by the alternator! Any ideas?

[ColinBarber]

It would drain in a few hours if the alternator wasn't working at all but it may be giving out a reduced output.

Is your engine check light on?

[imtiazhuss1]

No engine check light specifically. When it stalls while driving, the Battery and handbrake lights come on i.e.all auxillary lights come on and the car slowly comes to a halt (steering wheel gets heavy and brake pedal gets hard when pressed, as expected when car has shutdown). If it was a particular charge fuse or relay, how can I check for faulty relays (I think these are the green/yellow/blue square shaped objects in the fuse box under the hood)?

[imtiazhuss1]

Returning home last night I decided to check the Battery light. It was black and not green i.e.less than 65% charged. This morning before setting off I checked the Battery light again and it was green! It looks like, as was mentioned earlier, the alternator is not fully charging the Battery, but then why should it light up green this morning before setting off? Anyway, does anyone know where I can get a reconditioned alternator unit which does not cost the earth. Lexus has quoted me £370 including labour and vat and a reconditioned unit swap.

[ColinBarber]

There is somebody breaking an LS on eBay at the moment

[imtiazhuss1]

Hi Guys, just an update for those who are interested. I could not take anymore stalling, so I handed my car to my local Lexus Dealer. After investigating it appeared that a wire connecting to the engine management system under the passenger side glove box had come loose and was intermittently connecting/not connecting, hence the stalling. I was charged a total of £329 for the investigation and soldering of the wire. What do you think?

[ColinBarber]

Glad it's all sorted. I guess it took them a few hours to find the problem which is why the cost is so high.