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Discussion Starter · #1 ·
Hi I have a 1999 toyota camry LE 4cyl, I have a short ram intake and I notice once I get to about 70mph and I floor it, the rpms jump up to about 4000 and it just seems to hesitate and the tach will actually jump down a few hundred rpms to about 3800 (all while pushing down 100% on the gas pedal). I just had my 90k service done on the car including timing belt and it seemed to help a little and the rpms dont jump down quite as much but it still happens and makes for a hard time passing on the freeway. I had the service done at the toyota dealership and they pretty much looked over every engine component as part of the 90k service and said everything is perfect. So I was wondering would the short ram intake be causing the problems at higher speeds? The car runs perfect, gets good gas mileage, and runs perfect at lower speeds.
 

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Breakin' necks since '02!
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rev limiter? I have slow acceleration after 100mph...it'll take about 20 sec to get from 100 to 110.
 

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Discussion Starter · #3 ·
thats impossible, wouldn't the rev limiter just keep boucning off at a certain rpms and then I wouldn't even be able to get past 70mph... When i'm crusing at around 65 and floor it, it will go up to about 4k rpms, and slowly accelerate and creep down to about 3800 rpms but after that it continues to accelerate past 4k rpms. I noticed when it does that and if I slightly lift off the gas then apply it down maybe 90% it will actually accelerate faster than if I just left it floored.
 

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cause your car isnt downshifting.. if you want it to jump to past 4000 rpm then either press overdrive off.. or let off the gas and floor it.

maybe your using the a/c.. if your using the a/c.. the car wont tend to downshift as quick
 

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Discussion Starter · #6 ·
AC is off, 2nd gear goes to about 75mph if you leave the shifter in 2nd and take it to redline, it does down shift to 3rd though (whether OD is on/off) if you just leave it in drive and floor it, either way what would cause the rpm to jump to 4000 as your flooring it and about 1 sec after its been floored to jump down to 3800 and then continue to accelerate, but if I lift off the throttle to the point it does not upshift it will actually bring the rpms up past 4000 where the powerband seems to be and accelerate decently... hopefully this is all making sense
 

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I noticed that my car tends to accelerate faster (from a stop) when I'm not flooring the gas pedal. Work the gas pedal and acceleration is fast and smooth. On the highway, once I give it more gas, the transmission shifts immediately.

The only thing I can think of for your situation if the timing. Get it rechecked by the Toyota and clarify the situation with a technician. They'll probably be able to diagnose the situation immediately. Good luck!
 

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1, ur pullin a 3000+ lb car
2. u have a 4 cylander
3. u have an auto...big power loss
4. ur pullin that underpowered 3000 lb at over 70mph in 4th gear, 3rd if u have ect on or OD off
5. ur coeffiecient of drag is greater than .38(?)...that adds up to huge losses at speeds above 50-60
6. short ram, given its an even half decent filtration system will be better than stock, nothing truly noticeable though, so no worries ther
7. as for RPMs going down that could be quite a few different things....nothing clearly identifiable though in my book
 

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Discussion Starter · #10 ·
ag6286 said:
1, ur pullin a 3000+ lb car
2. u have a 4 cylander
3. u have an auto...big power loss
4. ur pullin that underpowered 3000 lb at over 70mph in 4th gear, 3rd if u have ect on or OD off
5. ur coeffiecient of drag is greater than .38(?)...that adds up to huge losses at speeds above 50-60
6. short ram, given its an even half decent filtration system will be better than stock, nothing truly noticeable though, so no worries ther
7. as for RPMs going down that could be quite a few different things....nothing clearly identifiable though in my book
I realize this, but any normal car should not be driving down the road at 4000 rpms and then go down to 3800 rpms while maintaining constant throttle position plus like I said if I lift off some what it will actually accelerate faster than if I just keep it floored. Even though it is not changing gears at all during this whole process
 

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^^sounds like a sensor reading error.....it still reads so ur engine light wont come on however it is probably causing error in caculations for feul/timing/o2 levels/basically anything relating to ignition and feul levels

*if it is

con: cant locate it unless u test like every sensor and know wut it should read at a given point, gl with that

pro: the sensor possibly linked could give way or fall out of an ideal range preset by the ECU software and u can identify it from engine light

con: it could just stay that way
 

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Discussion Starter · #12 ·
ag6286 said:
^^sounds like a sensor reading error.....it still reads so ur engine light wont come on however it is probably causing error in caculations for feul/timing/o2 levels/basically anything relating to ignition and feul levels
what sensor do you think would most likely be going out? And is there any way to test it besides replacing it?
 

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honestly, like i said, it could be basically anything, will it slow RPM's everytime u press the pedal down...take notice carefully......ud need to describe other symptoms in detail since this could be related to many many of the sensors, ther are so many factors its hard to pinpoint
 

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Give us more details. Could be a Stator problem in the torque converter.

The stator is mounted on a 1 way roller clutch.

a seased stator will give you normal acceleration and poor cruise speed.
a freewheeling stator will give shitty acceleration and normal cruise.
 

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IMO most cars that i've driven do not accelerate at maximum speed with the gas pedal all the way in the floor. Every car has a sweet spot on the pedal where you will get the most bang for your buck no matter how fast you are going. I too suggest you make sure your timing is correct. But besides that try not flooring it to pass on the hi-way.
 

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Discussion Starter · #16 ·
Reppinshadyvill said:
IMO most cars that i've driven do not accelerate at maximum speed with the gas pedal all the way in the floor. Every car has a sweet spot on the pedal where you will get the most bang for your buck no matter how fast you are going. I too suggest you make sure your timing is correct. But besides that try not flooring it to pass on the hi-way.
yeah its not a really big issue I just want to know why the rpms would just drop like that since its not like this happens in every car. I just want my car to run as efficently as possible. This is the only speed this issue arises in, car accelerates fine in every other gear/speed other than this one issue there is no other problem with the car that I can tell, its running perfect and averages around 30mpg.
 

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V8'sRGone
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two things, Converter and Intake

infox,
I am no expert on the cam auto pwr button but here is one thought. Once the ECU does its math on the intake vacum and decides it is stable it sends a signal to the trans to engage the clutch in the converter. That 200 RPM drop is your torq converter locking and saving you gas $$$$!

Hook a vacum gauge to the intake and tell us what the value is at WOT. For the most part. WOT will be zero vacum under max acceleration. As the engines makes power the vacum will climb. Again - the ECU is making the call about when to engage the converter.

Try gently taping the brake, many cars this will disengauge the lock up converter. If you can trigger the electrical connection to the ECU without actually applying the brakes, you may continue to feel the acceleration.

Then agian I could be way full of SH^T and find the cam don't even engage the L/U while at WOT!? Talk to the ECU, it will tell you....

OK - so the other thing is at WOT your new intake is not making as much power/torque. Bigger is not always better, that is a smaller diameter intake could have higher velocity inside and promote a better burn as it is mixing the fuel from the injectors better and stuffing the cylinder better. Advance your CAM timing and it may pull more RPM (this may just make hit the rev limiter quicker and not make the car any faster). Retard the CAM timing and it may make more torque (need to advance ign timing too).

Do you see what i am saying. There is more to it than shoving an intake and filter on it and the "seat of the pants" feeling is not always accurate. Get a stop watch or a puter and stop guessing, plot some data and record everything. From this you will have knowledge.

Just some thoughts, hope it helps....

/randy
 

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2010 Camry SE V6
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That happend to my 05 camry. It was a speed sensor in the transmishion. I changed it and then went on the highway and flored it. BAM!!! there wazz so much more pickup and it went much faster. i dont no if they are the same cods but the code was p0500
 

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Well I have a Gen 4. When it reach above 120km/h and u release the gas a bit, the car will decrease the speed significantly. I guess it's because it only has 4 speed I think. Anyone justify this?
 
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