Okay, here's the deal. 98GS400, if I got stuck in the traffic, and I am moving like 15 -25 MPH, when I let go the gas, you will see my engine drops the rpm to about 700, feels like I was in N in stead of in 1st or second gear, and I have to step on the gas pretty hard to get it moving again. When I drive on the freeway going like 60MPH or above, and if I let off the gas pedal, the rpm will drop a little like it supposed to do, and seems normal to me.

I hope I am making sense here, and can someone tell me if this is normal?

Thanks

 

umm.... just curious..... when you talk about the low rpm, do you have your AC on? not really relating to anything, but trying to gather more info

 

no, my AC was not on. so, as soon as i take the foot of the gas padel, the PRM will go from like 2000 down to 700 right the way, so, i have to push the gas a little harder to get it going again, so, it's not smooth. Like I said, if I am driving on a higher speed (40+), the PRM doesn't drop nearly as quick.

Thanks,

Dillon

 

ok, try this next time. keep the AC on, and let go of gas when it's ging very slow, and see if the rpm stays higher and more on the "normal" range

 

wow, that was quick. So, if the AC is on, and it's in the normal range, what does it mean? or, if it's not in the range, what could it be. I just notice this morning, when it's cold, like 30 degree, it will actting up lot more, means drop the rpm lot quicker.

Thanks again,

Dillon

 

yeah people say i have no life, just stay on the forum all the time

if that helps, i thikn it's close to the common low "idling" proble, though your case seems more serious coz' your car isn't idling. maybe you can try to clean the throttle body, check the o2 sensors, clean the air filter, etc...

now if that doesn't help.... that seems like some more serious problem that i can't think of a reason yet..

 

Might be low on tranny fluid...did you check?

 

Cleaned the throttle body, put a new K&N cold air intake about 1K miles ago. Changed the tranny fuild about 1K ago, as well as the spark plugs. I am hoping there's nothing wrong with my tranny. i might take it in for a flush.

 

yeah you might wanna flush the tranny fluid too, do a clean flush if you can, more money but cleaner

and just try the AC for the heck of it

 

Okay, I have tried the AC today, and it's helpping a little, the rps doesn't drop as quick, but, it's still dropping. I am thinking it might just be the way Lexus works, before as soon as I got up to like 35MPH, everything seems normal to me. How about you guy's car? what does it do when you let go the gas when you are going 5-10MPH? Does the RPM drop too?

Thanks,

 

i can try it on my car tomorrow. but then i have the diff gear, so it might be a bit diff. but i definitely don't have that "push the gas harder to keep it going" feel though

maybe should try a tranny flush and see what's up