Weird Behaviour

Memphis · May 10, 2006

Guys,

Here's an interesting scenario I came across in a friends car.

After driving for nearly an our straight, when breaks are applied the engine turns off, even though the clutch is fully pressed down. According to him, this happens mainly in heavy traffic (pretty obvious, considering it's usually a break-go-break cycle ) He says that this happens after driving for a while, which to me seems a bit weird.

Also, the engine doesn't turn off when the gear is in neutral and the vehicle is idling

Any ideas ? The car is 16 valve EFI and (according to him) doesn't have air flow sensors etc either.. so can't be a sensor issue....

My initial thought (after ruling out sensors) was whether there is something wrong in the clutch mechanism, which makes the clutch not to fully dis-engage when pressed down.

Pericles · May 10, 2006

Exact opposite of mine Mine when u let go of the gas the revs die down until stall for about 5-10 mins after u start the car. After that, its fine. Need to give a quick tap on the gas to recover. According to madmax, that happens until optimal operating temp is reached Get to work on the heel-toe methods when that happens . Until the engine heats, putting from 2 to 3 needs to be done over 3k RMP or done very quick to avoid the revs dropping to 0

Machang, check if its when the brakes are applied or when u let go of the gass (as in find a nice strech and stick it in neutral while traveling) It might be a idle control problem? I came across that while researching my problem.

Memphis · May 10, 2006

Pericles said:

Machang, check if its when the brakes are applied or when u let go of the gass (as in find a nice strech and stick it in neutral while traveling) It might be a idle control problem? I came across that while researching my problem.

According to him it's when the breaks are applied.. not when you let go the gas. when you let the gas go it's normal behaviour it seems.. but apply breaks and the revs just keep going down till the engine stops even though the clutch is fully down.

Pericles · May 10, 2006

Memphis said:

According to him it's when the breaks are applied.. not when you let go the gas. when you let the gas go it's normal behaviour it seems.. but apply breaks and the revs just keep going down till the engine stops even though the clutch is fully down.

Hydraulics problem when things heat up? I dunno.... Anyone else have theories?

Memphis · May 10, 2006

Pericles said:

Hydraulics problem when things heat up? I dunno.... Anyone else have theories?

See told you it's weird... and to add to this.. he says this happens in the mornings when the outside temperature is low.. and does not happen in the afternoons

Pericles · May 10, 2006

Oh BTW, what is this car?

Memphis · May 10, 2006

Pericles said:

Oh BTW, what is this car?

Corolla AE100

Update: We showed the car to my mechanic and he says that air is getting 'sucked in' from somewhere (probably a fractured tube), hence a detailed investigation is due to find 'from where'. In the mean time, he has increased the RPM a bit, so that there's a margin to prevent the revs going all the way down.