Hot Stall And Front Seats Heats Not Working

[SimonT2]

Has anyone had the problem of hot stalling - say on the A1 - come to a roundabout and Lexus 400 Mark III stalls - have to put it in neutral - turn key and then it goes all right until next roundabout. Am told it might be some sort of throttle potentiometer?? - has two bolts which connects it to engine casing - costs £184??? Anyone heard of this gizmo?

Other minor problem I have is that can't get two front seat heaters working - checked fuses - seem OK - are there any specific fuses under the seats - lights come on when you push the buttons on the dash but no heat ???

Also how does the rear seat cushion come out??

New Member??/ Please help - any ideas anyone ???

Simon T2

[GreyBeard]

Sorry, can't help at all, but welcome to the club!

once the others awake from their afternoon snooze, you'll get some more input!

[GreyBeard]

i'm surprised you got no more info about this problem - maybe no-one else ever has it!

[Steve]

does it only do it when you brake?

[ColinBarber]

Am told it might be some sort of throttle potentiometer?? - has two bolts which connects it to engine casing - costs £184??? Anyone heard of this gizmo?

That's the throttle position sensor. It needs to be adjusted correctly which should be checked first before replacing it and a proper clean of the throttle body.

[risingsun]

Has anyone had the problem of hot stalling - say on the A1 - come to a roundabout and Lexus 400 Mark III stalls - have to put it in neutral - turn key and then it goes all right until next roundabout

I recently travelled to the Midlands to buy a 1995 Celsior/LS400 Mark 3 which also demonstrated the same hot-stalling symptom you describe. At least it did on the longish motorway journey home to Cardiff. In the last two weeks of use, it's not happened again, although I should point out that it hasn't been driven under the same conditions since (no prolonged high-speed journeys since that day.) The idle speed does seem fairly regularly to drop down to barely 600 rpm, though.

Did your car also falter only on longer, faster journeys, or was it more common than that?

Anyway, Simon, I was just wondering if you've managed to solve the problem yet. And if so, how?

[GreyBeard]

mine only does it when it's very hot and been driven a bit hard. the garage seem to think there is a hairline crack in one of the heads; i also lose water blowing out the overflow, so they may be right - i should know by midweek. i hope your problem isn't the same, unless you've got a bucket of golden nuggets! :duh:

[risingsun]

the garage seem to think there is a hairline crack in one of the heads

I hope they're wrong, for your sake!

And I hope that that isn't what's causing my problem either, as I'd like to hold on to my "golden nuggets" for a while longer yet.

Thanks for the warning, though, and please keep us posted with any developments.

i also lose water blowing out the overflow

Do you mean that there's some overheating going on, with you having to regularly top up the coolant or something. (Please elaborate.)

I don't know if this is relevant, but I had a BMW once that used to drop some water on the tarmac after a bout of hard driving, but the actual coolant level never needed topping up, so I just assumed it was condensation being expelled from the air-con system. I don't suppose there's any possibility that could be what's what's happening in your case?

[GreyBeard]

water loss 1 litre every 20 miles or so! i took it in for the same reason in december, and was told rad had a leak, so new rad, and while i was at it, full service, all oils and fluids changed (except air con), new front pads, freed-off 'hand brake shoes', new HT leads, cam belt, water pump, adjusters, fan belt, one dist cap and rotor (the other was new from previous owner), thermostat, odds and ends, 2,650 quids worth! and now it looks like it is the head/s (which was my original thought) so i shall be having my negotiating skills thoroughly tested on wednesday!

[risingsun]

GreyBeard

Please tell us how you got on this week. Was it bad news after all, and if so, did you manage to stick it to them for their failure to diagnose the problem properly in the first place?

[GreyBeard]

no news yet, other than they accept that there is a leak from pot 7 into water jacket, but they haven't found out why. i told them that as i had diagnosed a head gasket and they had discounted my opinion, then i would be prepared to pay for parts but would be looking to them to cover the labour. (on the basis that most of the work i've already paid for includes the sort of work needed to replace the head gaskets, if that's what it is.) we'll see what happens on settle-up day! whenever that's going to be!

whichever way it goes, i'll post the garage name after it's all over, and either praise them for being 'good blokes' or slate them for being 'cowboys'. keep watching!

[maria]

Bob I take it you still have not got your car back yet then!!

I think it has spent more time with them that you.

Knowing where it is I have to say I am surprised reading all the problems you have been having, I have heard nothing but good things about them in the past, although they are very expensive.

They charged D once £50 to do 4 wheel tracking that was 4 years ago.

[GreyBeard]

yep still there, and in eBay parlance "comms poor"!

when they did my four-wheel tracking and camber they charged £54 plus VAT which i didn't think was bad, especially as both rears camber was out by one degree. (old springs i suppose, and worn bushes).

it's now been with them 10 days and they've not been able to give me any info about what it is and how long it'll take.

good job i've got a coupla other vehicles!

i'm going to get a coupla window stickers made up saying 'my other car's a Lexus, but it's broken down, again!' !

[antony]

Simon 2.

Thottle Position Sensor. Expensive sort of.

Youre seat elements are burnt out. If used alot they fail.

See a seat specialist company if you want them sorted.

From Lexus about 300 for the base & the back.

[antony]

The old MA70 Supra Turbo had head problems. Never Lexus.

[GreyBeard]

short-form update. head gasket was only leaking when engine was well and truly hot. heads pressure tested and OK, but both were warped (probably due to my son driving it after the water ran out thro the radiator crack, and no warning lights came on nor temp gauge rising, so he didn't know there was a problem til it ground to a halt, very very hot!) heads skimmed 6 thou, new gaskets, valves re-ground and sealed, etc. now goes OK, except hot stalling is the current problem, so throttle body cleanup on the cards this weekend. it's also reluctant to 'kick-down' sometimes, so gotta sort that as well.

[Scottie]

Simon - I have just become the proud owner of a LS400 P reg. When I purchased it the car ran perfect. On the first long run - Cambs to A1 / M25 junction as I stopped for the traffic lights the engine revs died away to nothing and I had to restart the car. I have had it to several Lexus / Toyota deales who cannot trace the fault as they cannot get it to replicate although since I have had the car (2 months) it does it to me on a regular basis. I did have 2 oxygen sensors replaced which were diagnosed as faulty.

I have noticed that it does not fault as described if I switch on the air conditioning which boosts the revs. I suspect that you and I share the same fault!

I am currently 'working with!' the garage I purchased it from to resolve the problem but they are becoming difficult as no one apart from me appears to be able to replicate the fault - I have witnesses to the numerous events!

I think my next course of action is to suggest the throttle position sensor and clean up of throttle body! Did yours solve your proble?

[shanice]

Has anyone had the problem of hot stalling - say on the A1 - come to a roundabout and Lexus 400 Mark III stalls - have to put it in neutral - turn key and then it goes all right until next roundabout. Am told it might be some sort of throttle potentiometer?? - has two bolts which connects it to engine casing - costs £184??? Anyone heard of this gizmo?

Other minor problem I have is that can't get two front seat heaters working - checked fuses - seem OK - are there any specific fuses under the seats - lights come on when you push the buttons on the dash but no heat ???

Also how does the rear seat cushion come out??

New Member??/ Please help - any ideas anyone ???

Simon T2

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[shanice]

colhenderson_@hotmail.com

Simon my GS300 SUFFERS FROM THE HEATED SEATS NOT WORKING(BOTH FRONT ONES), ALTHOUGH BOTH HEAT SWITCHES TURN ON OK.

Simon - I have just become the proud owner of a LS400 P reg. When I purchased it the car ran perfect. On the first long run - Cambs to A1 / M25 junction as I stopped for the traffic lights the engine revs died away to nothing and I had to restart the car. I have had it to several Lexus / Toyota deales who cannot trace the fault as they cannot get it to replicate although since I have had the car (2  :)  :) months) it does it to me on a regular basis. I did have 2 oxygen sensors replaced which were diagnosed as faulty.

I have noticed that it does not fault as described if I switch on the air conditioning which boosts the revs. I suspect that you and I share the same fault!

I am currently 'working with!' the garage I purchased it from to resolve the problem but they are becoming difficult as no one apart from me appears to be able to replicate the fault - I have witnesses to the numerous events!

I think my next course of action is to suggest the throttle position sensor and clean up of throttle body! Did yours solve your proble?

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[shanice]

colhenderson_@hotmail.com

Simon my GS300 SUFFERS FROM THE HEATED SEATS NOT WORKING(BOTH FRONT ONES), ALTHOUGH BOTH HEAT SWITCHES TURN ON OK.

Did you find a fix for this problem.

regards

colinn

Simon - I have just become the proud owner of a LS400 P reg. When I purchased it the car ran perfect. On the first long run - Cambs to A1 / M25 junction as I stopped for the traffic lights the engine revs died away to nothing and I had to restart the car. I have had it to several Lexus / Toyota deales who cannot trace the fault as they cannot get it to replicate although since I have had the car (2  :)  :) months) it does it to me on a regular basis. I did have 2 oxygen sensors replaced which were diagnosed as faulty.

I have noticed that it does not fault as described if I switch on the air conditioning which boosts the revs. I suspect that you and I share the same fault!

I am currently 'working with!' the garage I purchased it from to resolve the problem but they are becoming difficult as no one apart from me appears to be able to replicate the fault - I have witnesses to the numerous events!

I think my next course of action is to suggest the throttle position sensor and clean up of throttle body! Did yours solve your proble?

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