Problem with car around 4K rpm

[Scion1738]

In first gear when I accelerate my car at around 4K to 5k the rpms rise very slowly then when I'm in second gear at the 4K range I feel as if the rpm meter bounces and I don't know how to explain it but my foot that's giving gas feels like less power is being sent to the engine.. My car has 30k miles and it has nothing done to it other than a intake and catback.. I have headers and everything and I was planning on putting it on today but ever since I started noticing this problem I'm sketched out about doing the parts I will be getting a tune for the headers and everything in less then two weeks ? But if anyone has the same problem or can explain what it is that would be awesome thanks =)

[pantdino]

Originally Posted by Scion1738

In first gear when I accelerate my car at around 4K to 5k the rpms rise very slowly then when I'm in second gear at the 4K range I feel as if the rpm meter bounces and I don't know how to explain it but my foot that's giving gas feels like less power is being sent to the engine.. My car has 30k miles and it has nothing done to it other than a intake and catback.. I have headers and everything and I was planning on putting it on today but ever since I started noticing this problem I'm sketched out about doing the parts I will be getting a tune for the headers and everything in less then two weeks ? But if anyone has the same problem or can explain what it is that would be awesome thanks =)

Sounds like the engine isn't making power above 4-5K. Could be mixture or ignition, both of which are electronically controlled in this car. The bouncing tach needle makes me think of a rev limiter, which is also part of the ECU in this car.

[Ultramaroon]

How long have you owned the car?

[Scion1738]

A year and 4 months I'm the third owner

[Scion1738]

A ecutek stage 2 tune would it be able to fix this?

[pantdino]

Originally Posted by Scion1738

A year and 4 months I'm the third owner

I gather this is a new problem.


I think the answer is "take the car to the dealer." Hopefully their computer will be able to discern the problem.

[humfrz]

Originally Posted by pantdino

I gather this is a new problem.


I think the answer is "take the car to the dealer." Hopefully their computer will be able to discern the problem.

I agree, especially if this is a new problem.

Have you changed gasoline suppliers lately .. ??

I'd suggest you get the engine "right" before you start in with the headers & stuff.

An aftermarket tune may straighten up the engine.

humfrz

[Ultramaroon]

Originally Posted by Scion1738

A year and 4 months I'm the third owner

I asked because I wanted to make sure you weren't just describing the dreaded torque dip.

You're not going to get any love from the dealer with the aftermarket parts and tune. Not talking warranty, I'm just saying they won't know how to deal with it. Even if they could reflash back to stock tune it would run like shit because of the bolt-ons.

Maybe an air leak downstream of the MAF? Accidentally filled with regular gas? That would practically bring it to its knees.

[steve99]

Originally Posted by Scion1738

In first gear when I accelerate my car at around 4K to 5k the rpms rise very slowly then when I'm in second gear at the 4K range I feel as if the rpm meter bounces and I don't know how to explain it but my foot that's giving gas feels like less power is being sent to the engine.. My car has 30k miles and it has nothing done to it other than a intake and catback.. I have headers and everything and I was planning on putting it on today but ever since I started noticing this problem I'm sketched out about doing the parts I will be getting a tune for the headers and everything in less then two weeks ? But if anyone has the same problem or can explain what it is that would be awesome thanks =)

If the power drops off substantially over 4k and it just wont rev past about 4500 its probably in limp home mode, is the check engine light on ??

read engine codes woth scanner

[stevesnj]

Sounds like an electrical issue, coil pack maybe. If you have a multi meter test it out. Also could be vacuum leak, airbox leak.

[Sigh-on-Rice]

Sounds like the torque dip.

Or do you already know what torque dip is like for this car and still think this is something else?

[DustinS]

Is it a bump or a momentary pause in the acceleration? Does it happen every time?

I have been having intermittent pauses in acceleration at right around 4k RPM for as long as I can remember. Been through multiple tunes N/A and turbo and it's still there. I have caught it in a log and it just looks like everything pauses for a few seconds, then continues as if nothing happened. It's not something that is repeatable with any certainty. It just happens sometimes. Wondering if it is the same thing.

[Scion1738]

It's hard to explain but it basically just slows down in acceleration as if gives no power. It sorta feels like passing the red line limit just not as bad. As soon as it gets to 5k it's normal again

[Ultramaroon]

Was there a sudden change in performance, or is it possible that you noticed something that crept up slowly?

Seems silly but check your air filter.