How to cure cold weather hesitation on the 2nd gen 3sgte Options

[lagos]

3S-GTE Cold Weather Hesitation:
One very common problem with the 2nd gen 3sgte is that its almost impossible to drive on a cold day, before it has had time to full warm up. The car might hesitate, buck, or surge, just when you are trying to drive it as slow as possible. Here is a simple fix that should cure the issue once and for all, and give you a smooth driving car, hot or cold.



The problem is caused by the AFM. Locate the AFM Idle Adjustment screw thats circled in red in the above photo. You should be able to see a big philips screw that you can adjust. If you have a metal cap over yours, you will need to carefully drill it out to access the screw. Now that you have access to the screw, here is how to adjust it.

1. Use a sharpie or a marker to mark the current position of the screw. This is very important in case you ever want to put your screw back to its factory position.
2. Give the screw 2-3 full COUNTER clockwise turns.
3. Reset the ecu by pulling out the EFI fuse, or disconnecting the battery for a few min. Do not skip this part. Its very important.

Now go take the car for a drive and let the ecu relearn. It might take a few cold days before you can fully verify if the fix has worked for you. If you feel the problem has come back after a few days of driving, try 1-2 more turns. Just dont over due it, because that screw also has an effect on your idle and a small effect on the over all ignition timing of your motor.

You should notice a very drastic improvement in how the car drives when the engine is still cold. Once it has full warmed up, you'll probably also notice a nice boost in throttle response.

What happens when the engine hesitates and why does this fix it?
When your engine hesitates, its actually running VERY lean. For some reason setting the adjustment screw, so that the ecu sees a tiny bit of less air fixes the problem and lets the ecu maintain a correct a/f ratio during a cold drive.

Other notes...
1. Make sure you are not trying to boost a cold motor. This fix only applies to people who have issues driving slowly and normally on a cold day.
2. Remember how many counter clockwise turns you made. That way if you have any issues or regrets, you can always set it back to where it was.
3. If the problem also happens on a warm motor, make sure you are using ONLY OEM wires, cap and rotor along with NGK copper plugs and that they have been replaced since your swap. You can get a new oem set of ignition components from ebay for about 100bucks.
4. If the problem happens on a warm motor, under boost, then what you are feeling is knock response. If this happens, take your foot off the gas ASAP and lower your boost. Dont assume that 1xPSI is ok to "run" on these motors. Lower the boost by 1-2 psi until the problem goes away, and consider installing the tvsv led mod to see when your car is pulling timing due to knock.

Refer to this thread to read feedback from other 3sgte owners that have tired this fix.
http://mr2oc.com/showthread.php?t=285098

This post has been edited by lagos: Feb 15, 2008 - 3:01 PM

[rjbibeau]

sticky this shiznit

[malecrod]

Great job, Art. I have been under the impression that the cold motor hesitation was normal since it appears everyone with the 3sgte experiences it. Mine hesistates then surges when cold but once warmed up, it is perfectly fine. I will try this mod to see.

[lagos]

Great job, Art. I have been under the impression that the cold motor hesitation was normal since it appears everyone with the 3sgte experiences it. Mine hesistates then surges when cold but once warmed up, it is perfectly fine. I will try this mod to see.

You will be VERY surprised at how the car drives cold once you try this fix.

This post has been edited by lagos: Feb 15, 2008 - 4:07 PM

[presure2]

good job art!
stickied!