[marvakov]

Hi to everybody!
I own nissan sentra 2000gxe 1.8l
Recently it startet to have missfiring cylinder 4
The car is not moving properly since then like it.s bad idle then work good for some time and goes bad agein
Anyone has idea what can coast this problem
I was told it may be the injector
If it is what is the reasonable price for it the dealer ask for 170
Thanks

 

[i68k]

with a misfire, you really need to diagnose it. have you changed your cam and crank sensors recently? have you tested your coilpacks? did you pull the plug? hows the compression on 4? does it misfire say when you start it up when the motor is cold, or does it misfire randomly while driving? usually the injector is either clogged or not, its not usually happening randomly, but could be an electrical connection somewhere as well.

 

[marvakov]

I have change only vaccum cut valve recently dont think this matters
Yes the coilpack was check change #4 with #3 still missfiring in number
The car is doing it mostly when driving or stop on red light ussually when the weather is cold.
Dont know about the compression .
How can i check the wires which one you mean from the injecktor

 

[i68k]

it could be electrical to either injector, coilpack, or even the cps missing. usually if it misfires for a few seconds at startup, then goes away, is normally the coilpack failure, this is because the capacitors dont hold a charge when theyre old and cold. how bad does it idle, does it idle bounce 1krpm-2krpm? how does it idle in neutral when its acting up? have you changed the cam and crank sensors recently? it could possibly be vacuum related, usually you will get a vacuum code or loss of idle, not a misfire code. not sure which you mean by vacuum cut, theres the vent valve on the evap canister and the pruge valve on the intake....?

 

[marvakov]

Yes the car is bouncing.sometimes it just do it 1-2times and goes away.but sometime it start bouncing waile i am drivinv 40miles /h.and it does it countiniously for 2-3 hours
Whe the car is not moving it bounces and if i put neutral gear is like it goes away but no as soon as i start drive there it goes.
I havent change neither cam or cranc sensor .the one i change is called vacuum cut valve bypass valve.not the one by the cannister it located by the rear driveer side tire

 

[i68k]

so the entire motor is bouncing? or just the idle is bouncing? automatic or manual?

have you checked/cleaned out your egr and iacv yet? you should change both cam and cranks sensors if youve never changed them, those are common issues and they do control your timing. you can download the fsm for free around here somewhere as well:
nicoclub.com/fsm
allsentra.com/fsm
there should be troubleshooting in there somewhere. hopefully you dont have a bad headgasket.