This'll teach me to procrastinate in purchasing a repair manual..... I'm attempting to figure out why I have an engine surge at approx. 40 mph- while holding throttle steady. No engine light, but checked it for codes anyway and came up with code #31. Is there a site here that shows engine codes? when I put this item in 'search' it kicks me out saying I have to have a three letter word?..... Nitro

 

http://www.troublecodes.net/Lexus/

You should find your answer right here.....

 

Hey Nitro,

That surge is most likely your torque converter. Alot of older, high mileage coupes have the same problem, including mine. Right at 40mph you can feel the car jerk or sputter. I am assuming this is the same issue you are experiencing.

To date, I don't think there is any remedy except for replacement of the torque converter. Try searching the forum, alot of previous posts on this issue.

Just my guess, sounds like the same issue alot of other SC's are experiencing. Hopefully someone with better knowledge can chime in.

Thanks
LexusBiz

 

If it does turn out to be a torque convertor, be sure to read some threads about after market, high performance convertors. You might as well upgrade while you're at it.
Let us know how you make out.

Tim

 

Yes, this'll be interesting. I have an appointment with the lexus dealer in a couple days. From what I've been able to garner through this site, the Air Flow Meter will also cause surging. I wish I knew how to diagnose the AFM myself to see if it's related or not. The car has less than 90k on it and it's a shame anything is wrong. Nitro

 

You could try taking a look at the air flow meter to see if it is need of cleaning or not. Try taking a look at it. It's possible that some crap that went past the filter is on your meter and cleaning might be the easiest and cheapest fix.

 

Ahhh good info Tggoodrich/Nitro,

Never even thought of the air flow meter possibly causing the surging. Man I sure hope this is the issue and not the converter. I'll try cleaning mine out to see if it helps.

Thanks
LexusBiz

 

You may want to do a search first b/c I remember that you are only supposed to use a certain "safe" solvent to clean it. I think there is something sensitive or a seal or something (can't remember) that if you use too harsh a cleaner it will eat away at that.

Good luck

Tim

 

Any results from either of the two having the probs?

 

Okay, I got my SC400 back from Freeman Lexus in Santa Rosa, CA. The code 31 problem was not related to the surging issue. What WAS related is that the mechanic who did my 90K service, he used aftermarket cap, rotor, plug wire. They were not up to the needs of our SC's. After that $400 dollar replacement service my ride is MUCH more noticebly smoother. I havn't been able to drive it to much to see it the surging is all cured or not, but there is a big difference in the smoothness of how the engine is running. I've seen this in the past with some Honda Civic applications, but didn't even think about it with this issue..... Nitro

 

Did not have a chance this weekend to clean out the MAF. Hopefully sometime this week or weekend, I'll keep you posted.

Thanks
LexusBiz