New Engine, Reset ECU???

[Darkhound]

Hey Guys,

I uhh had to put in a new engine to my car about 3000k's ago and since then its beena bit rough running on a cold morning for about 2-3 mins after starting. Today I put my car on a dyno to test power/torque (I got relatively high for a stock car , 74kW, 160nM Torque) but when i got my AFR (Air Fuel Ratio) graph.. i was disturbed to find that the car is idling massively rich at lower rpm's. The cars been tuned etc... but its still running very rich.

the other day one of my mates asked if i did an ecu reset when i installed the engine and i kinda loooked at him with a blank face. Anyone know how to reset a toyota ECU? I tried the other day by disconnecting the negative battery connection, pressing the brake for about 10 seconds, reconnecting the battery and turning it on, and it felt like it did something.. but yeah anyone know how to do this?

Thanks, Max

[BeRad]

most stock ecu's will run rich...


the only way i can think of is disconnect it from 12v, but i dont see reseting it fixing your problems or if there is such a thing.

even if there is such a thing, i find it hard to belive that "reseting" the ecu will fix it when it was running fine up til now.... does the ecu throw any codes......


what do you consider massively rich...

[Darkhound]

As soon as i get the scanner to work ill show you the two results, but uhh ill see if i can describe.


The power curve on the power graph has a reasonable flat spot on it... which coincides with a massive drop in AFR on the air fuel ratio graph...

[BeRad]

what does it drop to? i dont need a graph, whats the a/f on idle and on this flat spot? maybe that engine standard has a flatspot in it...

[Darkhound]

Hey heres the graph... you can see what i mean by a massive drop :S No-one else that i saw had the same drop in thier graphs... so i presumed that its odd to have this kinda flatspot etc?

[BeRad]

what engine is it. o2 sensor working?

[Darkhound]

My car is:

Toyota Celica ST162 (1985)
3S-GE engine (First Generation)
2.0L

O2 Sensor should be working... but yeh :S wat do u think?

[Darkhound]

Heres the redbook link btw...

http://www.redbookasiapacific.com/au...p?key=TOYO85IL

[BeRad]

ahhh i use to have one of these before i threw the engine in the bin.... id check the o2 sensor, short out the diagnostics box and check that its not throwing a code....

[Darkhound]

hey umm, how would i short the diagnostics thing? What pins. 3 and some other thingo? The same ones we shorted when we tuned the timing?

And how would i go about checking the o2 sensor? Where abouts is it? Is that on the airbox? tvis? or extractors?

Sorry man, somehow i manage to install an engine into a car and yet strangly not know wat all the bits are. lol.

[BeRad]

ask the 162 dedicated thread the boys in there will know. i never had the stock ecu so dunno.

[ajh]

hey umm, how would i short the diagnostics thing? What pins. 3 and some other thingo? The same ones we shorted when we tuned the timing?

And how would i go about checking the o2 sensor? Where abouts is it? Is that on the airbox? tvis? or extractors?

Sorry man, somehow i manage to install an engine into a car and yet strangly not know wat all the bits are. lol.

Normally it's the same terminals as you use to check the timing.

EG: On ours, it's T and E1.

Also, not sure if this applies across the board, in the w/s manual for the 3S-FE, it says to reset the ECU, just pull the fuse out for 30 seconds.

[CrUZida]

Thats not running rich at all.
In fact its almost exactly where you want it.

[Darkhound]

:| Really? Not running rich? I dont understand?


Ill still try to reset the ECU using that fuse trick...

[CrUZida]

Your AFR's at full throttle are 12-12.5:1
Thats almost perfect for max power while maintain a good barrier of safety.

Its when the AFR's are below 11:1 that you'd consider it running rich

[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?