2ZZ-GE auto missing at take off

[Longdan]

I've got an Allex with a 2ZZ-GE and a tiptronic auto box. Lately, I've been noticing it 'misssing' when I go to take off from stopped. It's like the ignition cuts out for a split second whenever I accelerate from stopped. Then it gets going and all is fine. If I put my foot to the floor as soon as the light goes green then I don't notice it, but if I try and take off normally, the car gives a bit of a lurch then off it goes. This is something that is recent. The car has just gone over 100,000 kms.

Maybe the trans needs a tune up. Is that possible with these transmissions?

Someone suggested that maybe my throttle position sensor was dirty and needed cleaning.

Any ideas anyone?

[123R-Prozak]

Ok

Do you mean the auto slips like the revs pick up but no drive then in lunges into gear?

Or! It's a misfire and the engine itself struggles not the auto ??

[CHA54]

pull the ignition coils out of the head and look for hairline cracks down the side of the body. If there's any brown tinges aroudn the seams then it's likely they're arcing out to the head.

[Longdan]

Ok

Do you mean the auto slips like the revs pick up but no drive then in lunges into gear?

Or! It's a misfire and the engine itself struggles not the auto ??

Its not the auto slipping. Its more like the engine bogs a bit before the revs pick up when stating from stopped.

I asked about tuning the trans because it seems to be getting a bit jerky on the gear changes, possibly with age. I don't think the 2 problems are related, but they possibly could be.

[Longdan]

pull the ignition coils out of the head and look for hairline cracks down the side of the body. If there's any brown tinges aroudn the seams then it's likely they're arcing out to the head.

I checked the coils, and the plugs. No cracks in the coil housings or signs of arcing.

Its a momentary lag when I put my foot on the accelerator from stopped. Then it picks up again and off I go.

Maybe I should get my mechanic to have a look.

[123R-Prozak]

Lag like a downshift lag on the auto ?

Do a throttle body service and reset your ecu n see how u go?

Edited June 1, 2012 by 123R-Prozak

[Longdan]

Lag like a downshift lag on the auto ?

Do a throttle body service and reset your ecu n see how u go?

Yep thats how I would describe it.

I'll pull the battery lead tomorrow and see if that makes any difference.

Whats involved in a TB service? Take it out and clean it?

[123R-Prozak]

Woah hold up, so it is a auto shifting problem like how would u best describe it, need to determine of its your engine or auto

[dyslexik]

Transmission is holding gears more like it... jerky gear changes

[Longdan]

Problem solved!

All it took was to reset the ECU. Then took it for a blat down the motorway hitting lift a few times.

The take off is as it should be.

Its funny how so many issues can be solved by disconnecting the battery lead.

[Longdan]

Should I be careful to not let the positive battery lead touch earth while its disconnected?

The way I see it, this would instantaneously discharge the circuits and there would be no need to wait half an hour for them to discharge by themselves.

[123R-Prozak]

No

Intact, on the hummer I was told to disconnect the battery, both leads and hold them together to get rid of a engine light, and it worked ?