Gs300 Hesitation And 1-2 Shift Delay; Fixed?

[captaincrunch]

So, I have had this 1-2 shift delay, and acceleration hesitation problem for some time. I've read some about it on this forum and went through the "usual suspects". TPS checked and adjusted, MAF changed, reset ECU, all to no avail. Then saw something about the Accelerator Pedal Position sensor on a 400. I posted a question if the 300 has one. Must have been a dumb question, I got no responses. So, (I'm so brilliant), I called the dealer and, yep . . . it does, but they really think a lot of them!

Anyway, at $403 ea I began to rethink this thing.

So, I figured that the APP sensor tells where the pedal is, so it must be connected to the cable going to the throttle body. And, probably has something to do with the transmission shifting positions, also. So just to see what would happen, I loosened the cable out as far as I could (lots of slack in the cable), and drove it.

The 1-2 shift delay went away, but I had a lot of play in the pedal. So I began to slowly tighten the cable, maybe a 1/2 to 1 turn at a time until I was satisfied with the response.

Now, no 1-2 shift delay. No hesitation on acceleration either. The only thing is the pedal tension doesn't seem strong enough. I feel I have to hold my foot up while driving or I end up going 90+ MPH. I will try to tighten the spring one turn (read that here somewhere, too) and see if that helps.

My diagnosis: Over time the cable stretches out and gets the APP sensor out of sync with the TPS. I don't know that it's true, because it's so simple one would think that the Lexus techs could have figured this out. I also think the spring looses tension and causes the "feather touch" pedal effect.

So far it performs well for me now. I haven't researched to see what the "Lexus approved" adjustment process is for the cable yet, but will . . . . . . at some point.

[sakataj]

congrats on getting this resolved....let us know on any updates if anything changes

[captaincrunch]

UPDATE:

the only time I feel the hesitation and shift delay is when I'm easing around a parking lot, going less that 10mph with a lot of stop/starts. I took it to Lexus of So Atl and they said the ECU was really out of date and they did a re-flash. So far I can't really tell a big difference with that either.

The biggest thing is that the pedal is extremely light. Just barely pushing it and the car jumps. I have to hold my foot up off the pedal while driving, very uncomfortable. I've still gotta look into tightening the spring tension.