A quick question for those who own the VVTi models of the 400... I find that when I let off (partially or full) of the accelerator pedal, there is a lag between that time and when the car actually starts decelerating (maybe about a 1 second delay). I was wondering if this is just normal and part of the Drive-by-Wire setup? I used to own a 98 SC300 (also Drive-by-Wire) and don't recall having that issue.

 

Mine doesn't seem to do that. Not that I've noticed, at least.

The one semi-related thing I do notice is when lightly accelerating in 1st gear (from my driveway to the end of the block) and letting off before the stop sign, there's a surprising amount of engine braking. I always have to remind myself to wait a bit longer to let off the gas because of it. I suppose that's the exact opposite of your scenario...

 

98 SC400 here, I don't seem to have that issue either., deceleration is instant as I let go off the pedal.

 

Ok, so it sounds like my situation is abnormal. I wonder if the SC ECU has the learning feature (adjusts based on the driver's driving style)? It's done that since I bought the car from the previous owner.

 

Easy way to test that theory is pull the EFI fuse to reset the ECU.

 

It should. I installed a new dbw sensor on my sc300 and it took a few days to relearn my driving style.

 

Thanks everyone. Another quick question. Resetting the ECU would be just done by just pulling the EFI fuse? I recall reading others disconnecting the battery for something like 15 min to reset it.

 

I've seen it both ways. If there's a consensus, it's news to me.

 

Battery disconnect or fuse will work. As for the ECU learning, I don't think it takes that long depending on how hard you drive it.

 

When you pull the fuse (or disconnect the battery), tap the brake pedal a few times. This will bleed off any residual charge in the system. Then let it sit for 15 minutes, then reconnect everything.
Also, our cars don't need to relearn idle characteristics. These cars like to be driven for 10+ minutes after being reset. Resetting the ecu and letting the car idle to operating temp will cause the car to idle very low

 

My '98 does exactly as you describe if I'm cruising on 4th on the expressway but the lag is less than a second.If I lock it in first while I'm on a side street, I don't perceive any delay in its deceleration.

 

I'll have to see how the car drives when I get it back from the body shop. We had to pull the ECU out to get a duplicate key made so it should fulfill the requirements of pulling ECU fuse/disconnecting battery. Hoping the lag will go away as it is just weird as heck to drive like that.

 

Pop the hood and remove the big plastic cover to expose your throttle cable, I tightened mine to where there is no slack, these cables stretch and wear out, check that out to see if it's all tightened up and working the way it should without binding, you may be able to get your throttle response back, I'd also replace the spark plugs because there's cars are getting old and need that every little bit of maintenance!!!

 

^ My "throttle cable" was pretty loose and I tightened it along the lines of the non-VVTi cables, but it made no discernible difference. Then I was informed that we don't have throttle cables per se... What looks like a throttle cable is just a fail safe, with the real work being done electronically.