Occasional power loss - 08 SpecV

[MNSpecV]

Hello all! I've been reading the forum for a while, but still have not posted pics or replied to many threads. Pics coming *soon*... I have owned this 08 SpecV since June, and am loving it. The only issue that I have is that occasionally, I experience drastic power loss between 2k and 2900 RPM. It happens randomly a few times a week. I read up on the QR25DE a little, and was wondering if this could be the "power valve screws/butterfly screws" in the intake manifold? Any thoughts? Thanks in advance! -M

[Sentraserxxx]

Do you have any mods like a short ram intake or cold air intake?Asking cuz when I first put mine on i didnt tghten everything up god and the filter fell off and it would have like no power at all but then it would kick in after like 2 sec.

[cycspec-v]

hey man its some bull s*** problem in our ECU's ... you can get a re-flash from Nissan ...but its costs like 500 bucks .. mine happens after i drive like a steady speed for a little while and then it does it when i slow down and start to go again .. but if you turn your car off and turn your key on and off like three times and reset everything it will go away for a few days / minutes depending on what kind of driving your doing .. Sorry man just a stupid B-16 glitch

[MNSpecV]

I do not have any mods. The car is bone stock. It does the same thing to me after I drive steady speeds, so you must be right cyc... Would a warranty cover such a thing as re-flashing the ECU, or am I just boned? Also, if I did get it re-flashed, would this be a recurring issue? Thanks for the help.

[gray07]

Hello all! I've been reading the forum for a while, but still have not posted pics or replied to many threads. Pics coming *soon*... I have owned this 08 SpecV since June, and am loving it. The only issue that I have is that occasionally, I experience drastic power loss between 2k and 2900 RPM. It happens randomly a few times a week. I read up on the QR25DE a little, and was wondering if this could be the "power valve screws/butterfly screws" in the intake manifold? Any thoughts? Thanks in advance! -M

we have a single intake manifold... the butterfly screws are on the older qr25de...

look at courtestparts.com for a full parts on the web.

also http://www.nicoclub.com/FSM/Sentra/2007_Sentra/

i also experiance the power loss every now and then.. I notice it after the car sits for a while at a light. and with the K&N SRi it makes it worse.

I used a friends MSD dash hawk and i can see the Intake temps rise almost 20-40 degrees while sitting at a light.. Unfortunitaly the IAT is built into the MAF sensor and cant be moved to the bumper to read a lower intake temp.

maybe someone can put a resistor ont he correct wire to make the IAt read a lower temp... but.... do this whith caution becasue if the air is too hot and it reads a low temp you can possibly create a too rich condition and pop goes your motor.

it is not Nissan's tunning that is bad... I have experianced this in my wifes CX-7 which has the same motor as the speed 3/6. her does this a lot until I put a full cold air intake and drew air from a much colder area.
Modified by gray07 at 8:41 AM 10/22/2009

[MNSpecV]

I guess I notice it not only when the car is stopped at a light, but also notice the power loss in 6th gear running in the before mentioned RPM range (2k-2.9k RPM). I'm sure the outside temperature doesn't make a huge difference, but this has happened from 85 degrees down to 25 degrees(it's already been that cold this year...). I'm going to bring it into the dealer regardless, and I'll have a talk with the mechanic there as well.Thanks!

[nametakennow]

we have a single intake manifold... the butterfly screws are on the older qr25de...

look at courtestparts.com for a full parts on the web.

also http://www.nicoclub.com/FSM/Sentra/2007_Sentra/

i also experiance the power loss every now and then.. I notice it after the car sits for a while at a light. and with the K&N SRi it makes it worse.

I used a friends MSD dash hawk and i can see the Intake temps rise almost 20-40 degrees while sitting at a light.. Unfortunitaly the IAT is built into the MAF sensor and cant be moved to the bumper to read a lower intake temp.

maybe someone can put a resistor ont he correct wire to make the IAt read a lower temp... but.... do this whith caution becasue if the air is too hot and it reads a low temp you can possibly create a lean too rich condition and pop goes your motor.

it is not Nissan's tunning that is bad... I have experianced this in my wifes CX-7 which has the same motor as the speed 3/6. her does this a lot until I put a full cold air intake and drew air from a much colder area.

Reading a lower temp will cause the ECU to push more fuel, not lean the mixture out. Cooler air is more dense -> more air + more fuel = same ratio. Resistors in the IAT wiring are a proven way to lose horsepower and gas mileage. The relatively minor change is definitely not enough to harm your engine, though.

Your intake temp rises at a light due to a phenomenon often referred to as heatsoak. This happens because there is no outside airflow coming through the front of the car to push the engine-warmed air under the hood out. It is perfectly normal.

Anyway, to the OP: Take it to the dealer and have them take a look at it under warranty. It could just be a reflash of the ECU, which they sure as Hell shouldn't charge you for. Also, as someone said, the butterfly screw issue was for 02-06 QR engines.

[MNSpecV]

I appreciate all the advice, and the info on the butterfly screws. That's a weight off of my mind!

[gray07]

Reading a lower temp will cause the ECU to push more fuel, not lean the mixture out. Cooler air is more dense -> more air + more fuel = same ratio. Resistors in the IAT wiring are a proven way to lose horsepower and gas mileage. The relatively minor change is definitely not enough to harm your engine, though.

Your intake temp rises at a light due to a phenomenon often referred to as heatsoak. This happens because there is no outside airflow coming through the front of the car to push the engine-warmed air under the hood out. It is perfectly normal.

Anyway, to the OP: Take it to the dealer and have them take a look at it under warranty. It could just be a reflash of the ECU, which they sure as Hell shouldn't charge you for. Also, as someone said, the butterfly screw issue was for 02-06 QR engines.

I had a typo... I fixed it... It should have said... "too rich not too lean" I had corrected myself in the first post by lutting the rish after the lean.. but forgot to take out the damn LEAN in the sentence!!!!

Anyway.. MNSpecV. dont worry about it most cars with IAT this way have the same problem. unless you can move it or re-tune with a piggy or re-flash from Nissan... just get a CAI and it will help clear it up a bit in the warmer temps!!

and as for doing ti in the colder air.... not to sure...

MAKE sure you run 91 or aboe gas, becasue it could be as simple as running better gas!!!