Slow Acceleration

[yiujai86]

This started to happen about a year ago. I have no idea what might be causing it but I'm guessing some sort of sensor. It's hard to explain so I'll give an example.

Lets say I drive for 30 minutes. I turn the car off and go somewhere. Five minutes later, I'm back and I start up the car and pull out of the driveway. I floor the gas and it accelerates without a problem and the new tires actually lose grip. The problem is 2 minutes later at a red light/stop sign etc, the vehicle no longer has the acceleration and feels really sluggish up until 4k rpm.

So pretty much, anywhere between the time i start the car and 1 min, the car accelerates fine and yes the engine is warm because its been running for 30 minutes already.

Does anyone know specifically what might be causing this? Any input is appreciated, positively or negatively. Thanks

No! It's not because I have an ES 350 and that thing flies. I've driven the Camry for about 5 years now.

Things I've done:
Sea Foamed - All three options - Gas tank/ Engine Oil / Brake Booster
New Spark Plugs
New Engine Oil
New Transmission Oil
Flushed Radiator
New Tires/ Checked Air Pressure
New Air/ Filter
Removed two 12' Sub woofers w/box. Amp and Full Sized Spare.
I always run Premium Fuel

[new echo owner]

MAP sensor, maybe? Or restricted vacuum supply to sensor?

N.E.O.

[Luckynumber5]

Originally Posted by new echo owner

MAP sensor, maybe? Or restricted vacuum supply to sensor?

N.E.O.

The v6 Camrys don't have map sensors noob

I say try cleaning the MAF sensor with some electrical cleaner.

[new echo owner]

Ah, I just read LE and not the other part that said V6. Beside the slow acceleration, how does the car run? Any roughless or misfiring?

Blind in my right eye, can't read with my left. BTW, what the hack, is noob. I know what 'n00b' is, but not this one.

N.E.O.

[Luckynumber5]

I was just teasing ya man don't worry

[yiujai86]

Other than that, my car runs great. Ill try the MAF. Thanks for the input.

[Eye8Pussies]

do you smell any fuel when that happens?


it sounds like the symptoms of a knocksensor pulling timing and dumping fuel- mostly because you say that the car has absolutely no power until 4K, which is basically what it feels like when the knock sensor is going on the fritz

not sure why it would do that in your case though, since your car seems pretty well maintained and the mileage isn't that high

[Luckynumber5]

You might still be on to something there Eye8, a bad knock sensor can happen at any mileage but don't they usually throw a code pretty quick when something isn't right?

[new echo owner]

I was thinking of the EGR valve sticking or the coolant temp sensor out of range; however, either one would have cause some type of running problem beside slow acceleration.

N.E.O.

[Eye8Pussies]

Originally Posted by Luckynumber5

You might still be on to something there Eye8, a bad knock sensor can happen at any mileage but don't they usually throw a code pretty quick when something isn't right?

well, that's one of the misconceptions about knock sensors....just because they're "hearing" something and throwing your car into semi-limp mode by temporarily pulling timing and dumping fuel, they won't throw a code

the only time that you'll get the dreaded (especially for us boosted guys) p0330 or p0325 is when the knock sensor is actually "dead" or actually on its way to dying. Basically, when that happens, the knock sensor doesn't send any signals to the ecu- also another reason why we can't just pull the sensors out and drive without it. The ecu needs a constant variable signal from the knock sensors to keep it happy....which is another reason why we can't just stick a resistor in there and call it a day either.

But as much as it sounds like the symptoms of a knock sensor, I don't see why he that would happen to him either...usually, when a knock sensor is about to die, it'll randomly throw the p0330 or p0325 code every once in awhile and then eventually it'll stay on and they're done for sure.




As for what NEO said....I can see them as possibilities too, but the coolant temp would just make the car run richer, but shouldn't be to the point where you feel like the car isn't going. and as for the egr stuck open, possible if we're talking about low throttle, etc, but if even at full throttle it's like he's describing, then it's not the egr valve sticking open, as at WOT, the egr valve would be fully open anyway due to vacuum pressure from both openings on the TB

[new echo owner]

I agree with your assessment on those items, as I had mentioned, there would have been other symptoms besides slow acceleration if either one of them is the cause.

I wonder what his IAT is when he is having problem.

One more item to throw in for speculation, ACIS, what would happen if the valve stuck open?

N.E.O.

[Luckynumber5]

Nothing, it closes to modify the powerband up top. Even if it were stuck open or closed it wouldn't make much of a difference.

[ASG14]

Yup, Eye said exactly what I was thinking. I have a blown knock sensor right now, and lemme tell you, there is NO power till 4k RPM's.

The followinf video is my '96 V^ with a supercharger at full throttle with a vlown knock sensor:

[new echo owner]

I was under the impression that ACIS effective change the intake length by its operation; opens up to allow more air to enter into the engine at high speed and increase the air speed at low speed. Thus resulted in a wider power band.

N.E.O.

[Luckynumber5]

It does, but a malfunction won't cause serious symptoms and would be one of the last things to consider. not to mention to check it is as simple as messing with the vacuum lines and moving the actuator by hand to see if it is stuck.