Baby ///M3

I have a late production 03' SC430 and it's just passed 94k miles on the clock. The car's been very smooth for the past 20k miles except for one thing.

Lately I've begun to notice that when I slowly accelerate the car from a stop, if I were to very gently tap on the gas pedal the car would stutter (it feels like a very light tremble) for a bit, as if it's running out of gas. However, it only happens when I apply the gas pedal very gently.

Also, when I shift the transmission into D position, the car would suddenly surge forward for a bit, as if some invisible force was stepping on the gas pedal for me.

I can't seem to figure out what seems to be the problem. I've recently had a 90k mile service performed (timing belt/water pump/belts, etc.).

Has anyone had this problem before?

Thanks!

Jon

playa3uhh

Hm... This sounds odd. I would check the spark plugs & wires. Also try checking the fuel filter/system. I would suggest bringing it to the Lexus dealership and let the experts take a look. Just my two cents.

Yes

sometimes when they change the timing belt, it throws the timing off causing hesitation. i'd have the dealer start there.

tromly

+1, best to have the dealer handle this one as this is peculiar

Baby ///M3

Thanks! You guys are great!

I'll check with the mechanic who worked on my car to see if the problem can be traced.

Jon

scdroptop

iTrader: (1)

considering how much that 90k service is, I would absolutely start with them and tell them that this problem did not exist before you brought the car in.

If they tell you it's a coincidence, follow it through and see what they think the fix is...hopefully it's small like spark plugs, fuel pump, etc. Maybe a plug wire is not on tight?

scorpio74

The 06+ transmission is better in term of shifting into manual mode since it has 6 speed thus smoother transition.

Baby ///M3

scdroptop: You're going to laugh at me for this one. I actually intentionally told my mechanic not to replace my spark plugs, as they still had 30% or so life in them, and I was tight with money. So... I guess it might have been the belts.

scorpio74: Believe me. If I had a choice I would've bought a 07' white Pebble Beach car with all the more recent gadgets. However, I am now using the SC430 for my long distance commuting so I have to stick with my current ride.

Jon

antigeek

Have them check the TPS (throttle position sensor) as well. I had an intermittent problem that caused a quick drop in power after the car sat for a while. It never did throw a code.

scdroptop

iTrader: (1)

no laughing matter at all...i was cheap on my 30k service and tried to buy the plugs and DIY, that didn't work. Then I went to my "local shop" and had them take a look and they said it would be like $300...finally I took to lexus for $350 and they did it! lesson learned from me

antigeek

Would you elaborate, please? What went wrong with changing the plugs yourself? Access? Complexity? Too much potential to break something?

I found this thread for a '99 GS (nothing as illustrative or for SCs):
https://www.clublexus.com/forums/per...for-gs300.html