recently i bought a 02 maxima with a 6-speed. it was owned by an older person and the car had never been modified. i bought a open air filter with the correct adapter. then i removed the baffle from in front of the intake and replaced it with a chrome tube. looks good and sounds great. i also took the tube off the valve cover that leads to the airbox and installed a K&N breather(air filter)

Heres the problem. i noticed when i first start the car...be it cold or warm outside....when i take off...i get 1/3 into the throttle and the car hesitate's for a brief moment then takes off...after several moments of driving...and when the car is warmed up....this doesn't occur.

did i affect something in removing all the stock plumbing for the air intake?

 

I believe that's your problem right there, reverse that and see what happens.

 

Any pics of this set-up? Is everything hooked up properly?

 

Nope. I have that installed, too. No issues here.

 

could it be sensor related? maybe something got hosed with the MAF. check sensor wires and vac lines

you mentioned K&N. you're using a dry filter, correct? the "rechargeable" filters are wet and the oil will foul your MAF over time

 

Reset your ECU.

Did you touch the throttle body at all while installing this? Or clean the MAF? Don't take these questions as a hint to do so, cause you can cause damage that way.

 

CAN foul your MAF. IF they're over-oiled. You talk about it like it's bound to happen if you use an oiled filter. This is not the case.

 

~everything was brand new
~checked the mass air flow and it was clean.
~never touched the throttle body

why would venting the valve cover(crank case) cause an issue?




....and i don't have a "check engine " light...so should i still reset the ECU...and just how do i do that?

 

Are you absolutely positive the MAF is clean? Looks can be deceiving...

I'd take a can of CRC MAF cleaner...you can get it at Wally World, I think, for about $4, and spray down your MAF just for the heck of it. It doesn't hurt.

I thought my MAF was clean, and when I sprayed it down, actually gained some gas mileage back.

 

i vented my valve cover once and ran into the same problems...installd the hose onto the intake again and ran perfect again

 

I don't see how a breather filter could possibly affect driveability, as it functions the same way as the hose that runs from the valve cover to the intake.

The only difference between the two is that the hose creates a vacuum and sucks the pressurized air/oil mixture out of the valve cover and back into the engine where it gets burned up, where as the breather vents it directly to the atmosphere.

 

I'm not alone on this. To the OP reverse it and see what happens since its not that hard to take off the little filter and reattach the hose.

 

Yea but it sounds like he stuck a filter with a maf adapter so the hole for the hose on the air intake running from the air intake to the valve cover sounds like it is open.

 

Clean your MAF sensor, odds are that is the problem. Had a slight hesitation after installing a brand new K&N filter and when I sprayed my MAF with CRC's cleaner, I could see red running down the MAF. No problems since.

 

 

i am going to get a can of MAF cleaner today and see what that does...and reverse the valve cover breather

from the beginning i kinda ruled out a sensor issue mainly because:

1) i didn't get any type of engine code...even after 3 weeks of this issue
2) sensors (to me) are kinda on or off componets...either its bad and you would get the hiccup all the time or you wouldn't...not just when it cold.

as far as removing the breather. i race motorcyles and saw ..on the dyno..a 3 hp gain taking that hose out and removing that hot ,oily gas for reentering the engine. i figured if it gains on a bike...should work in theroy on a car...yes? as far as i know...its only for emissions reason, but upon thinking about it...maybe the car is set up where it needs that hot air on start up and for the 1st few minutes of run time...
something to think about...

keep you posted!

 

 

ok...i cleaned the MAF yesterday and this morning...smae hiccup..(note) hiccup starts around 3800...when the secondaries kick in). i rerouted the crankcase vent back into the intake and tomorrow morning i will see if thats the issue.

PS..whats the deal with the 3800 rpm secondaries..can they be eliminated or do they make power. on suzuki's..we remove the secondaries and it increases flow rate and midrange power...making the power curve on the dyno come in sooner..hp and torque. doesn't make any more hp. but for drag racing we do this mod all the time on newwer suzuki's

 

Why do people replace their vacuum hose wiu breather filters? It's there to suck up extra unburned stuff and reburn it. When you do take that pipe off, the stuff that was usually sucked back into the intake and burned is stuck either on the breather filter itself or in the opening. Plus it kinda helps with idle and stuff too. I'd advise you to take the lil mushroom off and reinstall the vac hose. Plus when you don't let that stuff burn up then it gunks up your valve cover and everything inside that

 

It's proven fact that hot oily hair ,taken from the crankcase ,reduces horse power and efficiency of the motor .crank aces are bent it back into the air box for missions purposes only .as far as I know ,no gain from this design.
colder the air the more oxygen contained within it .also remember that nitrous is nothing but frozen air mix it with fuel when you have a great power additive,but by itself it's still nothing but frozen air .

 

ok...problem solved.removed the K&N filter from the valve cover and rerouted the crankcase vent back into the intake and no hiccup this morning...so now i know thats where the issue is. there must be some sort of sensor in the throttle body that measures air temp or something and makes the car go lean or rich until it sees warmer air.

 

It's because the filter on the VC causes a lean condition since it's drawing in ambient air & pressure, vs vacuum under part throttle. There is no sensor in the TB aside from throttle position. The IT is in the MAF, but your problem was the breather causing a lean condition.

I had the same problem, went back to the PCV line where it should be and I'm fine now.

 

I was right

 

Anytime you pull in unmetered air, you will get a lean condition. In acceleration, the PCV should be closed. However, with the crank now having to force internal pressure build up out instead of it being pulled out through the intake.....this condition may allow the PCV valve to not seat closed and possibly pop open. This may be (or be part of) your "hiccup."

 

THANK YOU for finally saying it