# I've got an intake problem...



## nissanchik25 (Dec 21, 2004)

january 2nd i put in my new aem cold air intake in my 05 spec-v. i followed directions and i everything went smoothly... until i started it. my car wasnt breathing right. the rpms went crazy, and it was idling really funny until it would just die. so i thought maybe i just had to drive it around. so i did, but the funny thing was that i couldnt go above 2500 rpms... and if i tried, my car sounded like it was going to blow up. i pull back in my garage and took out the whole thing and put it back on. everything was tightened right, and the mas air flow censor was in place. can anyone help?


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## chimmike (Oct 17, 2002)

which way is the arrow pointing on the MAF?

unplug your battery for 10 mins or so to reset the ecu, and make SURE the MAF is pointing in the right direction.


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## pete? (Jul 6, 2004)

dosent the maf only go in one way? meaning you need an adaptor on one side and a sleeve on the other? make sure it is pluged in tightly, i know with my car (tho it is a b14) the plug dosent allways want to snap in. also the filter wouldnt have any type of shrink wrap or anything on it of that nature would it?


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## nissanchik25 (Dec 21, 2004)

i finally got it... i found out that the older sentras censor can face any direction like hondas...in the newer sentras the censor has to face a certain way so all i had to do was to turn it around. it took me forever to figure out something so freakin simple. now my car sounds like a wrx... you can hear the cvtc scream at 5000 rpms. thanks guys!


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## Jasper (Apr 2, 2004)

^ lol isnt that what mike said?
glad ya got it fixed.

hmm, hearing cvtc from 5000 up? i thought you didnt notice cvtc as much, since it was continuous. i know in my 1.8, you feel and hear the timing advance (right around 4500rpm or so, if my ear serves me right)...i didnt think it was quite as sudden in the cvtc motors.


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## chimmike (Oct 17, 2002)

nissanchik...hondas don't have MAFs. they have MAP sensors.


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## skatehard90 (Dec 20, 2004)

Do you have any problems with 'detination' on your 05 spec V with the air intake system?

cuz with the 05's spec V's will retard the engine when it senses 'detination'. . . and increased horsepower leds to 'detination'. . . 

and i don't think the knock dummy sensors work for the 04-05's . . . or am i wrong ?


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## skatehard90 (Dec 20, 2004)

Jasper said:


> ^ lol isnt that what mike said?
> glad ya got it fixed.
> 
> hmm, hearing cvtc from 5000 up? i thought you didnt notice cvtc as much, since it was continuous. i know in my 1.8, you feel and hear the timing advance (right around 4500rpm or so, if my ear serves me right)...i didnt think it was quite as sudden in the cvtc motors.


 Continuously Variable Valve Timing Control System 
Nissan's Continuously Variable Valve Timing Control System (CVTCS) electronically measures throttle position, vehicle speed and engine rpm, then adjusts the moment each valve breathes in. And it does this throughout the power band — from that first boost off the line to when you approach redline. Response time and efficiency are optimized. Power and torque, too.


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## chimmike (Oct 17, 2002)

skatehard90 said:


> Do you have any problems with 'detination' on your 05 spec V with the air intake system?
> 
> cuz with the 05's spec V's will retard the engine when it senses 'detination'. . . and increased horsepower leds to 'detination'. . .
> 
> and i don't think the knock dummy sensors work for the 04-05's . . . or am i wrong ?


detonation isn't caused by increased horsepower.

detonation is caused by using lower octane gas which can cause hot spots and preignition of the fuel before spark is activated.

higher octane gas is recommended in the manual because higher octane gas burns slower and therefore prevents detonation.

the 04 knock sensor is perfectly fine and does its job properly. No need to screw with it. Any car with a knock sensor will retard timing when detonation occurs.

Please do some more research before making statements like that next time


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## chimmike (Oct 17, 2002)

Jasper said:


> hmm, hearing cvtc from 5000 up? i thought you didnt notice cvtc as much, since it was continuous. i know in my 1.8, you feel and hear the timing advance (right around 4500rpm or so, if my ear serves me right)...i didnt think it was quite as sudden in the cvtc motors.



wrong and wrong.

1) CVTC isn't what you hear at 5000rpm. it's the butterfly valves opening up the secondary intake runners.

the next person I hear say they "hear cvtc" and KNOW what cvtc stands for is gonna get slapped.

2) Jasper, what you hear at 4500rpm is the slight butterfly in the QG opening fully to allow full flow into the engine from the intake manifold. NOT nvtc.


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## Zac (Mar 10, 2004)

chimmike said:


> wrong and wrong.
> 
> 1) CVTC isn't what you hear at 5000rpm. it's the butterfly valves opening up the secondary intake runners.
> 
> ...


I thought the secondaries opened at 5200?


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## chimmike (Oct 17, 2002)

I'll open your secondaries up permanently


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## Zac (Mar 10, 2004)

chimmike said:


> I'll open your secondaries up permanently


 :crazy: That sounds like a threat to me. I may have to get an APEXi-V-TEC AFCII to combat this...or then again I can always defend myself with the high quality SS autochrome or OBX header that cracks in 2.


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## skatehard90 (Dec 20, 2004)

chimmike said:


> detonation isn't caused by increased horsepower.
> detonation is caused by using lower octane gas which can cause hot spots and preignition of the fuel before spark is activated.
> higher octane gas is recommended in the manual because higher octane gas burns slower and therefore prevents detonation.
> the 04 knock sensor is perfectly fine and does its job properly. No need to screw with it. Any car with a knock sensor will retard timing when detonation occurs.
> Please do some more research before making statements like that next time


well duh, i didn't explain myself well enough for you! 
I know what detonation is, but what i was trying to see is that mods usually lead to a higher probability of detonation. . . 
example! 
---> turbo on QR25DE, giving 3-5lbs boost=increased compression=increase horsepower=increase chance of detonation
you'd have to run a higher octane to compensate for the turbo. . . or you'll be detonating left and right

so unless that is all wrong and i'm 'makin this up' then i'll write up a full report next time


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## skatehard90 (Dec 20, 2004)

chimmike said:


> wrong and wrong.
> 1) CVTC isn't what you hear at 5000rpm. it's the butterfly valves opening up the secondary intake runners.
> the next person I hear say they "hear cvtc" and KNOW what cvtc stands for is gonna get slapped


was this dis for me too mike? cuz i don't know what you are talking about. . . i just simply stated a simple understanding of what CVTC was because i thought the other kid got confused with continuously variable transmission CVT. . . 'hint' Ford Freestyle

oh well. . . have a nice day

sorry to upset you chimmike *praises* lol


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## chimmike (Oct 17, 2002)

no the dis wasn't for you.

boosting a QR doesn't give it more compression, it gives it more air, and at a higher temperature even with an itnercooler. the hot air gives a better chance for detonation en mass than does cooler air, hence why intercoolers are commonly used.


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## jamesdean (Jan 4, 2005)

chimmike said:


> detonation
> 
> the 04 knock sensor is perfectly fine and does its job properly. No need to screw with it.


Correct me if I'm wrong, I thought that the knock sensors were a little over sensitive in these cars. They can pick up normal engine noise and mistake it for pinging. Especially since the QR25 isn't a smooth or quiet running 4-banger. I read up somewhere that you can use a resistor that will slightly desensitize it which would be better than relocating it to the firewall.


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## Mr SEntra (Oct 7, 2002)

jamesdean said:


> Correct me if I'm wrong, I thought that the knock sensors were a little over sensitive in these cars. They can pick up normal engine noise and mistake it for pinging. Especially since the QR25 isn't a smooth or quiet running 4-banger. I read up somewhere that you can use a resistor that will slightly desensitize it which would be better than relocating it to the firewall.


That was primarily for the '02 and '03 QR's. From what I know, the knock sensors were replaced and are much better now.


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## skatehard90 (Dec 20, 2004)

jamesdean said:


> Especially since the QR25 isn't a smooth or quiet running 4-banger.



you don't think the QR25DE is a smooth running engine ? how so? . . . cuz the stabilizers it's equiped with does a great job at making it nice and smooth. . . and for a 4 banger, it's really smooth, no vibration at idle, none on the hwy, etc 

have a nice day


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## Zac (Mar 10, 2004)

The engine itself is relatively smooth...the transmission isnt as smooth....a lot of this depends on the driver's ability to shift. IMO polyurthane motor mount inserts from ES or PTI make the car overall smoother other than at idle. Even with out balancer shafts removed, the car isnt horribly unsmoothe. Keep in mind, inline 4 cylinders tend to vibrate significantly more than other engines.


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## jamesdean (Jan 4, 2005)

Put the QR up against an Acura or Toyota 4 popper. You will notice a big difference. Large displacement/long stroke=vibration/noise in I-4 engine. Even with the balance shafts. The 2.5 is a brute, not much refinement like other Japanese engines.


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## skatehard90 (Dec 20, 2004)

jamesdean said:


> Put the QR up against an Acura or Toyota 4 popper. You will notice a big difference. Large displacement/long stroke=vibration/noise in I-4 engine. Even with the balance shafts. The 2.5 is a brute, not much refinement like other Japanese engines.


well first of all. . . Toyota 4 bangers don't come close in size(L) or stroke(mm), so proportionately the QR25DE seems better in smoothness 
on the other hand. . . the only acura i can think of with same size is the TSX, but still i don't think the stroke is near the spec V's. . . yes yes yes the acura and toyota engines are smooth, but come on, they don't possess the torque that the QR25 has. . . 

lets put it this way. . . the engines from acura and toyota are like puppies in torque. . .while the engine from nissan is a big dog for torque. . . which would be easier to control? puppy i think! so nissan does a good job at controling and smoothing out their great dog. . . lmao

i'm sorry but vibration and noise for the specV is not a problem at all ! 
it's just a great engine. . . so get over it
the transmission on the other hand. . . well *cough* that's another story . lol


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## jamesdean (Jan 4, 2005)

It's obvious you love your Nissan. That's cool, I like mine too. Let's make a better comparison though. Take the QG18 from a Sentra and put it up against the Toyota 180hp 1.8L in a Celica. Same displacement. The Nissan 1.8 makes much less power (hp and torque), but I bet you will find the Toyota is much smoother. The point I'm trying to make is, Nissan builds kick ass engines and a decent cars around them. But they lack the refinement of other Japanese automakers. Nissan engines are louder and vibrate more, which effects the knock sensor retarding the timing. Do a little research. A stock QR is a very inconsistent in dyno readings. A QR with the KS relocated or slightly muted is one of the most consistent engines you will find.


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## SR20dee (May 1, 2002)

Continuously variable timing Control?

butterfly valves?

Knock?


"detination"?

<--- confused


why is this still open


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