07 Reving Problems?

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Feb 25, 2007 | 01:11 AM

#21

ReV2Red

I haz da turbos

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From: In the basement

Quote:

Originally Posted by Enron Exec

First of all, i wouldnt free rev a motor too high or too much, especially on a new motor. Your spinning the motor but not putting any of the normal loads on it. Its better to let the bearings see only the normal forces it is expected to experience throughout its life instead of all sorts of forces. This is even more true on heavily modded cars and FI'ed cars.

I think what your seeing, when the tach is dropping, is just the ECU keeping the car from dropping revs too fast to where it will stall the motor.

Exactly. Most cars do this. Just to prevent the engine from stalling if the revs drop to fast.

Feb 25, 2007 | 02:42 AM

#22

JunJTan

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Joined: Oct 2005

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From: OR

yes, most car do that when engine isn't warm enough. my 06 does it too.

Feb 25, 2007 | 09:07 AM

#23

Sharif@Forged

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Forged Performance

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From: Marietta, GA

Nothing is wrong with your engine...but first of all..congrats on teh VQ35HR.

You are one of the first to roll around with that engine in a 350Z.

When you decel, the ECU will fuel cut, and at 1500rpm or so, the fuel kicks back in, which causes that slight pause. No worries...its all good.

Feb 26, 2007 | 07:26 AM

#24

nismology1

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Joined: Jul 2004

Posts: 332

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From: South Fla.

Quote:

Originally Posted by Sharif@Forged

When you decel, the ECU will fuel cut, and at 1500rpm or so, the fuel kicks back in, which causes that slight pause. No worries...its all good.

+1. This is the correct explanation. As the engine revs down, it's in the "coast" fuel trim where injector pulse width is very very very low. When it reaches around 1500 RPM it enters idle fuel trim.