MadMaxSC400

I've heard it mentioned in here - I can't imagine that the temperature change would cause the motor to run dangerously lean. Has anyone here bypassed this?

SCV8

Hey,how's it going?
I did try this,thinking that it may improve the response/power like the port polishing,airbox mods,etc,but it leaned the car out to where it made great power in the lower gears,then bogged a little on the freeway in the lower rpms.
It didn't seem to improve with any ecu learning either,so I just put it all back.

If the airflow meter is the restriction,then making the TB flow better may not even help at all,but I wish I could do some real testing with larger injectors,ported out airflow meter,bypassed coolant onTB,using the piggyback ECU to dial it all in.
Heck,maybe even extrude hone the intake manifold as well.

BTW,Leo did a great job on the ecu tuning,especially considering that it wasn't even my car that the tuning was done to! Says alot for Toyota quality,and consistency in manufacturing I guess.

MadMaxSC400

How did you do it? It's been getting so hot the motor is pinging a lot, so I've been having to put my bypass plug in the ecu. I figure that down here in cali where it's been breaking 100 degrees more heat in the intake is the last thing I need.

Gixer 1000

http://www.supraforums.com/showthrea...coolant+bypass

Vegassc400

Madmax, how can you tell the car is pinging?

What's a bypass plug?

MadMaxSC400

It makes a clicking noise, especially under load and on hot days. I don't know if it's a pinging problem or not. the bypass plug is a little cap for the harness so you can remove the ECU upgrade for emissions or whatever.
I should find the coolant hose and clamp it off to see if it changes the idle before I actually bypass it.

SCV8

If you want to try and bypass the throttle body,the 5/16 coolant line runs from behind the TB towards the front of the car.
It's a pain since you have to get into some tight places and remove a baked on old hose.I used some long,curved needle nose pliers to break the old hoase loose.
The problem with the whole thing is that the difference created from doing that lies between the airflow meter and the TB,and cannot be measured by the TB.
You could try and mess with the mixture screw under the aluminum plug on the side of the airflow meter,but mark the original location first,before turning it(in=richer;out=leaner).