Stalling

[Mik_D]

I am fed up When going slowly around roundabouts and coming to a stop or slowing down in traffic the car stalls. It is bad when cornering as I lose the steering and it makes other road users confused as to my the burk in front has decided to stop on the apex of a corner or at the traffic lights when they turn green. Things are bad enough with the cruddy fuel economy I'm getting (£30 = 100 miles-if I'm lucky). Why does my car want me to look like an idiot? Please help me to sort this out. The car is a mk 111 turbo auto. The worst is stalling in peak traffic and taking five minutes of click-clicking before the git starts again. My other car is off the road so my supra is my main car for the moment.

Regards

Michael

[richysupra]

I am fed up When going slowly around roundabouts and coming to a stop or slowing down in traffic the car stalls.  It is bad when cornering as I lose the steering and it makes other road users confused as to my the burk in front has decided to stop on the apex of a corner or at the traffic lights when they turn green.  Things are bad enough with the cruddy fuel economy I'm getting (£30 = 100 miles-if I'm lucky).  Why does my car want me to look like an idiot?  Please help me to sort this out.  The car is a mk 111 turbo auto.  The worst is stalling in peak traffic and taking five minutes of click-clicking before the git starts again.  My other car is off the road so my supra is my main car for the moment.

Regards

Michael

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mine had the same problem in the cutting out i know it may sound funny and i thought it when i was told also but it did actually stop it all i had to do with mine was to change the cooling system fluid and antifreeze i couldnt believe it when i was told i thought he was pulling my plonker but it has stopped straight away. i might be wrong on your car but hey it worked for mine so give it a try doesnt take long.... hope it works for you let me know k

[Karma Supra]

I swear I already replied to this.....

have you checked keads, plugs, and for moiture/oil in the plug galleries?

[Mick24]

Yep - Could be the Coolant level low causing it to cut out and will give you a

Poor Cold Start also - come across a similar problem on MR2's and Celicas.

[Martin F]

Yep - Could be the Coolant level low causing it to cut out and will give you a

Poor Cold Start also - come across a similar problem on MR2's and Celicas.

                                                           

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WTF !!!

How would low coolant cause your car to cut out ?

[Karma Supra]

WTF !!!

How would low coolant cause your car to cut out ?

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I must admit its a new one on me too!!! yesterday Milly's car poped its top heater matrix hose, emptying the coolant system almost immediately! the car ran fine, I just stopped when I saw steam.....

[Mick24]

WTF !!!

How would low coolant cause your car to cut out ?

If the Coolant level is low or has an air lock,it will play Havoc with the Coolant Temp.Sensor and Cold Start Temp.Sensor - they are Thermistor type sensors converting resistance measurements to a voltage signal for the ECU.

They will alter the fueling/ignition timing according to Engine Coolant Temp - so if the coolant is low or the system is air locked - it will probally lean out the mixture the hotter it gets until it "stalls out" or the ECU will put in a substitute value( limp home as opposed to walk home) and put the Engine Management Light on.

:P

[Martin F]

so if the coolant is low or the system is air locked - it will probally lean out the mixture the hotter it gets until it "stalls out" or the ECU will put in a substitute value( limp home as opposed to walk home) and put the Engine Management Light on.

                                                      :P

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The important word there is 'probally' (which i guess is some alternative spelling of the adverb 'probably'), you don't know for sure.

As far as i'm aware the coolant temperature sensor is only used to enrichen mixture during cold start and then to monitor temps during operation.

Do you not think the oxygen sensor would have a part to play in the scenario you described above?

I would suspect (yep i don't know for sure) that if temps are seen to increase beyond a certain value that timing would be adjusted rather than fuelling to try and bring them back down again. If you continue to enrichen fuelling then you'd need to ignore the closed loop feedback from the oxygen sensor or factor some variable in.

Sorry i just don't see it.

If your coolant is so low that you've introduced an airlock into the system then you really don't deserve to be driving a Supra.

Well maybe a MKIII <------------------- Purely for Karmas benefit :P

[richysupra]

so if the coolant is low or the system is air locked - it will probally lean out the mixture the hotter it gets until it "stalls out" or the ECU will put in a substitute value( limp home as opposed to walk home) and put the Engine Management Light on.

                                                       :P

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The important word there is 'probally' (which i guess is some alternative spelling of the adverb 'probably'), you don't know for sure.

As far as i'm aware the coolant temperature sensor is only used to enrichen mixture during cold start and then to monitor temps during operation.

Do you not think the oxygen sensor would have a part to play in the scenario you described above?

I would suspect (yep i don't know for sure) that if temps are seen to increase beyond a certain value that timing would be adjusted rather than fuelling to try and bring them back down again. If you continue to enrichen fuelling then you'd need to ignore the closed loop feedback from the oxygen sensor or factor some variable in.

Sorry i just don't see it.

If your coolant is so low that you've introduced an airlock into the system then you really don't deserve to be driving a Supra.

Well maybe a MKIII <------------------- Purely for Karmas benefit :P

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usually id agree with you on that one as ive never in my 10 yrs of working on cars ever come accross this but wen i was told i thought watthe hek give it a try nothing to loose but it did actually work on mine mad i know, mind you the coolant wasnt low on mine it was full but i changed it anyway and working great now i cant realy explain it maybe it was just luck what i was told and worked but hey im not complaning it did work

[Mik_D]

Well my other car actually has a knackered top rad hose so for lightning to strike twice is a bummer. I will assume that the temp sensor (the one fitted on the thermostat housing) is not integrated into the feedback system. I rewired it and it goes straight to gauge. However it still does not work anyway and I've bought a new sensor unit (£8 from Halfords). The other sender you speak of is not shown on my Haynes wiring diagram (there's a surprise) But if the anti freeze is old (and it probably is) then the electrolytic resistance (or conductance) will have changed.

I will part drain it and then refill with new anti-freeze. It is raining at the moment so i'll get onto it later and let you know. However it didn't stall today as the weather is cooler than it has been so there is a starting point. The mixture must be going too lean causing failed combustion and then stalling under loading.

Also my electric ariel has decided to stop working

Regards

Michael

[Mick24]

Trying to diagnose a problem "remotely" is difficult but there is a vast amount of information here on the Forum and from the Members.

The Coolant Temp. sensor is only a small part of the Injection System but a critical part of it - if you have faulty sensor or a broken wire on that circuit,the ECU will think that the Coolant Temp. is extremely low and increases the fuel injecton volume by twice that of the standard volume - when the engine is Idling it will cut out.

The Oxygen Sensor also supplys the ECU with a Voltage value,depending on the difference between Ambient air on the inside of the sensor and the outside of the sensor exposed to the exhaust gases - the ECU uses the Ox signal to increase or decrease the injection volume, to keep it as near to the stoichiometric air-fuel ratio.

Both of the above sensors if faulty with store a code in the ECU and put the Engine Management Light on.

Mik_D - Do you have any Fault Codes stored in the ECU ??

It might narrow your problem down if you have.

It might be a good idea to give the engine a service if its not had one recently:

Carry out a Compression Test

Replace the spark plugs and check the HT leads.

Replace the Fuel Filter and Air Filter.

Clean the Throttle Body inside with Carb.Cleaner.

Check for any split vaccum pipes which would give you a Lean mixture.

Check the Auto.Transmission Oil.

Hope you cure the stalling problem as it can be dangerous in heavy traffic conditions.

PS - Sorry for the Poor Spelling !! ;)

[Mik_D]

Trying to diagnose a problem "remotely" is difficult but there is a vast amount of information here on the Forum and from the Members.

The Coolant Temp. sensor is only a small part of the Injection System but a critical part of it - if you have faulty sensor or a broken wire on that circuit,the ECU will think that the Coolant Temp. is extremely low and increases the fuel injecton volume by twice that of the standard volume - when the engine is Idling it will cut out.

The Oxygen Sensor also supplys the ECU with a Voltage value,depending on the difference between Ambient air on the inside of the sensor and the outside of the sensor exposed to the exhaust gases - the ECU uses the Ox signal to increase or decrease the injection volume, to keep it as near to the stoichiometric air-fuel ratio.

Both of the above sensors if faulty with store a code in the ECU and put the Engine Management Light on.

Mik_D - Do you have any Fault Codes stored in the ECU ??

It might narrow your problem down if you have.

It might be a good idea to give the engine a service if its not had one recently:

Carry out a Compression Test

Replace the spark plugs and check the HT leads.

Replace the Fuel Filter and Air Filter.

Clean the Throttle Body inside with Carb.Cleaner.

Check for any split vaccum pipes which would give you a Lean mixture.

Check the Auto.Transmission Oil.

Hope you cure the stalling problem as it can be dangerous in heavy traffic conditions.

PS - Sorry for the Poor Spelling !!    ;)

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A-Ha

I have drained some coolant (mucky brown) replaced a litre of ethol-glycol antifreeze (lovely clear deep blue) and I actually replaced the temerature sender to te temp gauge and it works !! :D :D . Went out in it to put some fuel in (ongoing they love me there as I have my own pump and they can afford to pay a guy to cover 24/7 just to keep the supe topped up). It didn't cut out once However I do have a flashing o/d off signal but it does not cover anything other than speed sensor broken wire etc. I don't have the super monitor. The diagnosis module array is corroded to blazes and I can't get a reading although I can cancel the flashing (for ten miles then it comes back).

Thanks for everything and I hope this has solved the problem. I'm offto the pub now to win the quiz . We got slaughtered last time so its been two weeks since a victory. Maybe things are looking up

[Mick24]

Glad you managed to sort it out

Hope you win the Quiz !!

[Karma Supra]

If your coolant is so low that you've introduced an airlock into the system then you really don't deserve to be driving a Supra.

Well maybe a MKIII  <------------------- Purely for Karmas benefit  :P

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Bahhhhhhhhhhh Codswollop :P

[richysupra]

well im glad thats all sorted now anyway b4 a fight breaks out with all the members lol