New Engine, Reset ECU???

[Darkhound]

Ahhh okay. Well shows how much i know about that. i just saw a big drop in AFR and figured that could possibly be the reason for why my car doesnt like running when it starts up

[CrUZida]

That big drop was probably when the operator put his foot to the floor.

[Darkhound]

Ahhhhhhhhhhhhhh okay, makes sense. Thanks heaps.


On another note... got any idea why my car runs rough when i cold start it?

[CrUZida]

Care to elaborate on what motor it is?

[Darkhound]

its a 3S-GE. First generation. 2.0Litre. Completely stock as far as i know except for the exhaust which is lukey branded. Beyond that, i'd need to know what kinda info ur after?

[Vios-GT_07]

i have that same problem .. 1NZ..

morning it's running rough.. and also choking and stuttering under load.. i'm subscribing to this thread to see your opinions and thoughts maybe it'll apply to my solution

anyway i've changed spark plugs and that helps a bit... going to try a throttle body clean up and very soon do injectors.. as i've noticed fuel filter is buggered (changed that as well)

[CrUZida]

Whoops, missed your post earlier about the type of engine.

Unless its been rebuilt, its time for a major 'tune up'
You need to replace all the rubber hoses on the motor, making sure there are no air leaks anywhere.
Remove the throttle body and the ISCV, clean them out thoroughly, they get gunked up and don't work as well as they should. You may need to readjust the TPS after refitting the throttle body.
Remove the cold start injector, make sure its spraying properly. Test the cold start injector time switch, make sure its within spec.

If you don't have any manuals, I highly suggest you get a Gregorys manual, and learn everything you can from it.

[Darkhound]

Umm well dad and i replaced the engine 3000k's ago so i dont think its that.. because we cleaned out the crud from all the moving bits that we could.. checked all the hoses and pipes and yes we do own a Haynes (Gregorys) manual specific for the car...

Its really odd tho why its doing it. Ive just gone out to the car and tried to reset the ecu again by disconnecting the battery and pressing the brake pedal for a few seconds... about to go for a reasonable drive so if that works ill let ya know...

There was only two complications we had when installing the new engine.

1) the throttle cable didnt quite fit properly for some strange reason on the new engine so we took it to a highly respected adelaide mechanics (Blackwood Dyno and Tune) and they built us another bracket...

2) A vacuume hose that comes out of the TVIS/Throttle Body was hanging loose.. and we couldnt work out where it when. The boys who fixed the throttle cable plugged it into a location and it worked fine after that.

That was before i started driving it. And 3000k's later its developed the above named problem... so Im lost :S

[Darkhound]

Uhh update:

I did the whole ecu trick where you dc the battery and then press the brake for a few mins... then reconnect the battery. And it fixed the problem but i rkn it'll come back again... we'll see how it goes.

Maybe you too Vios can try it?

[Mr Revhead]

sorry, resetting the ecu doesnt do anything.

another internet myth.

[Darkhound]

sorry, resetting the ecu doesnt do anything.

another internet myth.

Im not convinced. Its the only explanation as to why my car was consistently starting up very very rough.. and is now starting up correctly... As far as im concerned, its worked for me

[Mr Revhead]

how can it do anything?
stock ecu can only adjust within very tight preset parameters.