Acceleration and RPM Performance Question
#1
Driver School Candidate
Thread Starter
Acceleration and RPM Performance Question
Ok,
I'm having issues with accelerating and my rpm gauge is too high when on certain speed.
Firstly, not sure if my 91 LS400 should be driving at 2500rpm when I'm crusing at 60mph. I think that's too much. But I'm not sure. Also the foot pedal feels hard when I accelerate. On my brothers 90 LS400 the pedal is light and just a tap will accelerate the car. Mine doesn't accelerate fast. Not sure what the issue it. I mean it could be quite a few things but wanna know where to start. Everything else is fine. Fires up with no hesitation. Idles normally between 600-800rpm and stays very steady and quiet.
I already replaced the dirty air intake filter. It helped alot BUT still it doesn't accelerate fast and RPM is still at 2500rpm when I'm going 60mph. It's been eating alot of gas lately. Where should I start with diagnosis?
A tune-up? Check/clean throttle body?
I'm thinking both of those. Any other suggestions? Thanks in advance.
I'm having issues with accelerating and my rpm gauge is too high when on certain speed.
Firstly, not sure if my 91 LS400 should be driving at 2500rpm when I'm crusing at 60mph. I think that's too much. But I'm not sure. Also the foot pedal feels hard when I accelerate. On my brothers 90 LS400 the pedal is light and just a tap will accelerate the car. Mine doesn't accelerate fast. Not sure what the issue it. I mean it could be quite a few things but wanna know where to start. Everything else is fine. Fires up with no hesitation. Idles normally between 600-800rpm and stays very steady and quiet.
I already replaced the dirty air intake filter. It helped alot BUT still it doesn't accelerate fast and RPM is still at 2500rpm when I'm going 60mph. It's been eating alot of gas lately. Where should I start with diagnosis?
A tune-up? Check/clean throttle body?
I'm thinking both of those. Any other suggestions? Thanks in advance.
#2
Lexus Champion
I already replaced the dirty air intake filter. It helped alot BUT still it doesn't accelerate fast and RPM is still at 2500rpm when I'm going 60mph. It's been eating alot of gas lately. Where should I start with diagnosis?
A tune-up? Check/clean throttle body?
I'm thinking both of those. Any other suggestions? Thanks in advance.
A tune-up? Check/clean throttle body?
I'm thinking both of those. Any other suggestions? Thanks in advance.
on the tune-up parts, the caps, rotors, and engine coolant temperature sensor need to be the real Toyota part (easy to find at 25% off from online parts departments of Lexus dealerships such as Sewell, Park Place, etc.)
the wires and plugs for the tune up just need to be Denso or NGK, no need to go through a dealership
if all of that doesn't fix it, come back and we will get to the bottom of it!!
PS - on the 2500 rpm at 60mph, either your tach is not reading correctly or your car is never going into overdrive. (the latter is more likely)
Last edited by LScowboyLS; 09-18-13 at 01:38 PM.
#3
Driver School Candidate
Thread Starter
Thanks cowboy. Yeah the next thing up for this vehicle was gonna be the tune-up for me. Ok so I'll go ahead and do it.
But the O/D issues...guess I'll need to look into it. The O/D light never came up on the dash but I'll see what I can find. Thanks.
But the O/D issues...guess I'll need to look into it. The O/D light never came up on the dash but I'll see what I can find. Thanks.
#5
Driver School Candidate
Thread Starter
Alright guys, need a lil help quickly. Cleaned the throttle body and putting it back together as I post this. There is a cable I can't seem to identify which is hanging loose. Can anyone help me? Not sure if I disconnected it or where to plug it in. I attached a quick video showing it. Can someone tell me what this wire is for and where it gets connected to? Thanks in advance.
#6
Driver School Candidate
Thread Starter
NVM. Looks like I got another wire on the other side just the same also disconnected. I think they were like that. Anyways fired the car up without a problem. The pedal still feels hard. I'll take it for a drive tomorrow sometime after work and see how it does.
#7
Pole Position
There shouldn't be any extra wires hanging in the engine bay, every wire is for something. Although, that isn't the way it came from the factory with that much wire exposed and with tape on it. It looks like it might go into the firewall b/c of the grommet it has on it. Maybe the previous owner had some kind of aftermarket stuff there, like an alarm horn. People do put some crazy aftermarket stuff in their vehicles. Mine was wired up with lights and siren, previous owner was a detective. I removed all that so I wouldn't be tempted to use it and then get arrested.
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