My 1996 ls400 stalls while driving

[Tom Mcquillan]

😚

[cruisermark]

Hi Tom

The Mark 3 LS is known for this problem i.e engine stalls when slowing down from speed (i.e coming off motorway) - this problem is normally cured by cleaning the throttle body

This may also be linked to capacitors in the ECU but im not 100% sure therfore leave it to someone more knowledgeable to confirm

[Tinonline]

Also a symptom of a MAF unit failure. 
 

Some cars will run with the MAF disconnected…it’s a good way of fault testing as the car won’t stall and it seems to be a bit of a safety/get home.

[Malc]

Tom hi  welcome to the Forum .  especially with a wonderful Mk3

Has this just started happening ?

Can you tell us more about your wonderful car ?

 

see the authoritative posts above ......  every little helps 

I know it can initially be a bit scary in some situations when rev cut-out happens .....  so tips to avoid ........

 

NOW ......  after a bit of a long run and this happens to me, it  only happens when I'm slowing down and the revs drop away  ......... totally ............  I can just pop the auto gearstick into    N    and restart the car whilst it's very slowly moving / running along , say on a roundabout approach and you want to really keep going ...... If I'm at red lights and it happens then just turn the ignition off and again in   N  or  P  restart her and you will get full revs as tho' nowt has happened 

OR  pre-empt the situation arising and when you  " know or feel  " it's cut out is imminent then just keep your foot gently on the accelerator pedal to keep enough revs until you're in a better driving onwards position

If you're at red lights and you can feel it happening with the revs reducing then just pop her into  N  and you will see the revs gently edge back up to an ok level 

Something minor to live with for the utter pleasue of having a Mk3 methinks

But a bit scary the first couple of times tho'

I've never bothered to sort it out BUT I do understand that when this happened to the Mk3 in the USA then Lexus did actually have a recall and I guess permanently solved the problem somehow

You're a lucky guy having a Mk3

Best wishes

Malc

[steve2006]

There was a recall for this problem and a modified engine ECU was fitted but that was too long ago to be of any use now.

I would begin with checking all the vacuum pipes ( they are everywhere) for tightness and fitting ( they tend to crack where they push on).

Throttle butterfly plate tends to get carbon build up blocking the bleed air hole.

IACV have been known to go faulty, the earlier version was rebuildable but the later is a sealed unit.

Plus all the previous suggestions.

Keeping the AC on all the time may help as it increases the idle speed slightly, the difference in MPG is negligible given the engine size and it also helps everything lubricated.

Any white smoke cloud from the exhaust on a cold start up?

 

[Cotswold Pete]

I had same issue with my Mk3, which slowly got worse.  I had a clean throttle

It was the ECU, but never got around to fixing when I gave my car away to a mate for spares on his Mk3

But once the problem started occuring, I did find that initally putting the AC on kept the problem at bay, but after about a year, even this trick was not helping.

I also resorted to Malcs trick when coming off a motorway, but I found it a little stressful on busier junctions.

My MK4 never had the problem, and I think that is coz the capacitor problems had been drained out of the supply chain by the time Mk4 came along.  Though mine is a very late Mk4, so not sure if earlier Mk4s ever suffered.

 

[Malc]

47 minutes ago, Cotswold Pete said:

but I found it a little stressful on busier junctions.

I got used to it these past 11 years and 117k miles ........... the stress level diminsihes with experience I find BUT sometimes I forget andf get caught out .....  think I'm driving the other car maybe ........  I tried lots of the above suggestions too

Even wrote to Lexus about the recall .  fell on deaf ears  ( of course )  BUT the only other option was to just let her depart and I'm NEVER going to do that ...... she's too precious and whilst worth zero in cash terms is actually a $million to me 

Keep the car and develop the 6th. instinct to keep going 

Best wishes

Malc

[Razor61]

This may help

https://www.lexusownersclub.co.uk/forum/topic/124943-ls400-idle-and-cutting-out-issue/