ser spec v problems

[Arm&hammer]

my ser spec v is havin some problems everytime i come to a stop and put it in neutral it turns off and then wont come back on and then i barely get it to turn on and when it does run its so slow it balerly pulls past 3000 rpms idk what it could be ive turned it off of safe mode and nothing im stuck any help would be good

[Shift_2WIN]

sounds like your MAF is dirty or bad. When u drive it wont go above 3000rpms? Or does it struggle to but still make it above that? When the MAF is bad or so dirty that the ecu thinks its bad, the ecu limits rpms to 2000-2500, at least in Maximas. Seeing as how Nissans are very similar in the way they do things, maybe check that out first. Any codes? Maybe you need to clean your TB, IACV too. If the MAF is filthy, then chances are so are your TB and IACV.

[Arm&hammer]

[QUOTE=Shift_2WIN;38833897]sounds like your MAF is dirty or bad. When u drive it wont go above 3000rpms? Or does it struggle to but still make it above that? When the MAF is bad or so dirty that the ecu thinks its bad, the ecu limits rpms to 2000-2500, at least in Maximas. Seeing as how Nissans are very similar in the way they do things, maybe check that out first. Any codes? Maybe you need to clean your TB, IACV too. If the MAF is filthy, then chances are so are your TB and IACV. My MAF is dirty and it sometimes does this, I need to clean everything and i have a replacement MAF ready to go in, just to cold right now.[/QUOTE

what is the maf is that the mass airflow sensor? and that might be it cuz ive cleaned it before and the car turned on for a lil bit

[Arm&hammer]

it does go above 3 grand but there is no point to it cuz of lack of power

[Shift_2WIN]

yes the MAF= Mass Air Flow Sensor, TB= Throttle Body, IACV= Idle Air Control Valve. Try cleaning all of the above 1st.

[Batlground]

There should be a check engine code.

[Shift_2WIN]

Not if its dirty but still functional, like mine is. I have no codes....but then again I can rev as high as the limiter lets me and my power is fine, so yea maybe you should have a code. Do you? If so get it read and tell us what it says.

[Theycall_Metue]

yea like they said, clean them and recheck. make sure its plugged up also. the more you give it gas the more it bogs at low rpm right? it should feel like your running hella rich

[Arm&hammer]

Not if its dirty but still functional, like mine is. I have no codes....but then again I can rev as high as the limiter lets me and my power is fine, so yea maybe you should have a code. Do you? If so get it read and tell us what it says.


it throws a code for misfire on cyl. 2 its not the coil pack i fixed that now its still barely pulling

[Arm&hammer]

yea like they said, clean them and recheck. make sure its plugged up also. the more you give it gas the more it bogs at low rpm right? it should feel like your running hella rich

yea the more gas the more it bogs but i cleaned every sensor the iac maf, everything and all it helps is it cranks a lil better but still pulls slow. since the car broke down in ky im going there tonite to check the compression see if it blew up does anyone know what the compression shold be?

[Theycall_Metue]

look it up on wikii
or google the engine spec
it should tell you the compression ratio

[Shift_2WIN]

Try going to these forums and asking as well...http://www.b15sentra.net/forums/showthread.php?t=177917 http://www.b15u.com/forumdisplay.php?f=30&order=desc&page=2
http://www.b15sentra.net/forums/forumdisplay.php?f=2

[Andr3w]

Do you have a header installed on the car? What year is it and how many miles?

normal compression should be 181 across the board. No lower than 150 and no more than 14 variance between the cylinders

[Z U L8R]

those cars are notorious for the catalytic converters coming apart, clogging, and some even trash motors.

federal law states the manufacturer must cover the catalytic converters 8 years or 80,000 miles.....

with a good scanner you can drive the car monitoring the datastream and isolate the problem, or lack thereof, then investigate the mechanical failure further.

another thing is, since those cars are drive by wire, the ecu controls how much the throttle opens along with the idle. basically the idle air control valve is built into the throttle body. and since it is all electrical it could be failing....

however since it throws no code, and since the ecu controls the throttle body, it could also be a bad ecu. that's usually the last place to check though since there's no real test for an ecu other than trying a known good one, which would mean you'd have to get one from a junk yard so you wouldn't pay 234e32432424 million dollars at the stealership, however you'd need the new ecu to be reflashed to use it.

first thing i'd do is unbolt the cat and run open header and see if the car has power. that will deduce that as the culprit.

well actually the first thing I WOULD do is hook up the snapon modis scanner and look for pending codes, then monitor the datastream while driving it...but if you don't have access to a scanner then start with my first suggestion and unbolt the cat.

tell you what, do that then post back with your results.

Dave @ Pro Auto Care

[Andr3w]

The cat that comes apart on our cars is the pre-cat located in the exhaust manifold itself. That's why I asked if he had an aftermarket header and how many miles. Hopefully this isn't a pre-cat related issue. Awaiting on compression check results...

[Z U L8R]

oh yeah, i forgot that it's right on the head.....

well damn that sux lol, least we're on the same page

Dave

[Arm&hammer]

im going to check the compression tomorrow morning but it does have problems with the cat converter im goin to write them down here tomorrow afternoon

[Arm&hammer]

Do you have a header installed on the car? What year is it and how many miles?

normal compression should be 181 across the board. No lower than 150 and no more than 14 variance between the cylinders


it is a 04 its got 193xxx miles on it and it is bone stock we travel with it to work ad back from ky to ga

[Arm&hammer]

those cars are notorious for the catalytic converters coming apart, clogging, and some even trash motors.

federal law states the manufacturer must cover the catalytic converters 8 years or 80,000 miles.....

with a good scanner you can drive the car monitoring the datastream and isolate the problem, or lack thereof, then investigate the mechanical failure further.

another thing is, since those cars are drive by wire, the ecu controls how much the throttle opens along with the idle. basically the idle air control valve is built into the throttle body. and since it is all electrical it could be failing....

however since it throws no code, and since the ecu controls the throttle body, it could also be a bad ecu. that's usually the last place to check though since there's no real test for an ecu other than trying a known good one, which would mean you'd have to get one from a junk yard so you wouldn't pay 234e32432424 million dollars at the stealership, however you'd need the new ecu to be reflashed to use it.

first thing i'd do is unbolt the cat and run open header and see if the car has power. that will deduce that as the culprit.

well actually the first thing I WOULD do is hook up the snapon modis scanner and look for pending codes, then monitor the datastream while driving it...but if you don't have access to a scanner then start with my first suggestion and unbolt the cat.

tell you what, do that then post back with your results.

Dave @ Pro Auto Care


u got a good idea im going to try this and post back tomorrow

[Andr3w]

Well I can think of 2 problems that it could be. These 2 are very common mess ups with our car.

1. The pre-cat in the exhaust mani breaking apart and pieces returning into the engine.

2. The butterfly valve screws in the intake manifold coming out and entering the motor.

-Two detrimental things that can completely destroy the QR25 if not addressed asap.

[greengolfbal]

193k!!! Nice!!! I would check compression first with that many miles. My old civic back in the day only made it 188k before the cyclinders just couldn't do it anymore. After that, could be the mass air flow sensor. Had similar problems with a GTI VR6 I used to have and it was the MAF. Best of luck.

[greengolfbal]

Hey Andrew, do you know where I could find a write up on how to fix the butterfly screws? Going on 88k miles and haven't had a problem....knock on wood. But I'd like to fix it.



Well I can think of 2 problems that it could be. These 2 are very common mess ups with our car.

1. The pre-cat in the exhaust mani breaking apart and pieces returning into the engine.

2. The butterfly valve screws in the intake manifold coming out and entering the motor.

-Two detrimental things that can completely destroy the QR25 if not addressed asap.

[Z U L8R]

you can put mild threadlock on em. just take em out one by one that way you don't move the butterfly then your throttle binds up n stuff.

just be careful, even easier you could put a dab of silicon on the back.

the main problem i found with the qr25's is the damn balance shaft assembly.

i made 305hp @ 8 or 10psi i forget, which is pretty much double what they make stock, ends up ripping the teeth off of the balance shaft assembly and the teeth clog up the oil strainer making low oil pressure resulting in rod knock.

worst part about it was he had the jwt balance shaft delete kit the whole time but just didn't have it installed. i later installed it when i fully built his motor with custom rods and all.

hope that helps,

Dave

[Andr3w]

Here you go Dan
http://specvforum.com/viewtopic.php?f=78&t=137

I just did mine at 130,000 miles lmao. They were all there thank God.

It is a whole lot easier than it looks. Takes about 20-30min to take the IM off. It's not too bad. Be sure to use RED LocTite. Let me know if you have any more questions.

[preferredduck]

There should be a check engine code.

that's what i'm thinking, it should throw a code for sure if something is not right. clean all of the parts the other dude listed on the manifold it may have just enough room to not throw a code yet.

[Z U L8R]

i wouldn't use red loctite...blue is more than adequate...red = never get them out, in case you need to adjust it, not a good idea.

[Arm&hammer]

sorry i havent had a computer till today but im going to check the compression tomorrow and put the results on here i need help im gonna take off the cat too and the butterfly flaps too and see if that solves it

[Arm&hammer]

No compression in 2 cylinders so we gonna change the motor idk what happened to it it ran fine and now it jus took a dump while driving... can anyone tell me where I can get that motor for cheap or a 01 maxima motor ?