[tdkclydes]

Hello , I am a new member in search of some help with a 03 Sentra 1.8 ( w coil packs ) . When the car is cold and when 1st started the engine will surge and some times die . It will take several attempts to keep it running . After 1 - 2 minutes the idle will even out . If I allow the car to sit and come up to full temp it will drive fine . If I try and drive the car as soon as the idle stops surging the car has no power and surges and bucks . I can drive the car ( reaching full operating temp ) and the condition will not change . How ever if I stop and turn the car off and restart it it will run fine . What is changing when I turn the car off and restart it ? I just had a diagnostic done and have been told it needs a new timing chain .
Prior to the diagnostic the only codes that showed were 1147 = not reaching max voltage / 0139 sensor slow responce / 0340 cam position sensor . I cleaned the connector for the cam sensor and the 0340 has not returned . I have also replaced the post cat o2 sensor .

 

[i68k]

P1147 NISSAN - Heated Oxygen Sensor 2 Maximum Voltage Monitoring Bank 1
P0139 NISSAN - HO2S12 Slow Response Bank 1 Sensor 2
P0340 NISSAN - Camshaft Position Sensor Circuit Bank 1

did you clear your ses codes after you changed your parts? they may need to be cleared, you can do the pedal dance, or use an obd scanner. once you clear them you can see if they pop up again, or if your symptoms change, when you have ses codes the ecu maybe adjusting your fuel trim incorrectly causing your idle issues. if your cam sensor codes comes back, replace both cam sensor and crank sensor, if it comes back again, you need to check your charging system, make sure your battery terminals are super tight, and has good ground contact, check your battery voltage motor on & off. otherwise you have wiring issues/bad connection/bad ecu.

im not positive, but i believe you have 4 o2 sensors, did you change both rear/post cat sensors? the code you have is for the bank1 sensor, maybe you changed your bank2 sensor...? once the car is warm, and you restart, your o2 sensors are already hot, it could be the heater on the sensor failed, which would cause it to run like doodoo when its cold, and losing timing wont help the ecu correct the problem.

also, dont forget to check your vehicle for recalls, the cam sensor has been recalled for the 1.8 motors, not sure if youve done the recall, or if it applies to your vin.

 

[tdkclydes]

No recalls on this vin # . Today I retated the cam position sensor 180 degrees . When I started the car it ran fine . Turned it off and returned the sensor to tha normal mounting position and the surging and bulking returned .
Tha sensor is flat on 2 sides ( 12 -6 ) and round on the other sides ( 3 -9 ) . The flats side are not even in regards to the airgap between the flat side of the sensor and the trigger wheel . The airgap is smaller on the side when mounted 180 degrees . Ha has any one had this experience ?
I have read on some of the sites that there is a cam position sensor made that does not have flat sides .

 

[i68k]

i dont think it matters which way you mount the cam sensor, as long as its in the cam sensor hole. its really just reading the teeth on the trigger wheel and providing the pulses to the ecu. just make sure its sealed, as oil will leak out overtime if the oring isnt set. have you checked the fsm for the specs on cam sensor spacing? it should say the space between, but i dont remember seeing this info.

both my crank and cam sensor are metal type sensors, not the flat plastic ones. im not sure if theyre still being made, or who makes them, but mine were duralast i got from autozone. basically instead of the flat plastic, it was like a metal cylinder shape. looks almost as if they fitted a metal cylinder over the plastic one.

like this one:

 

[tdkclydes]

I spoke to a service tech today and he said that the reason that rotating the sensor 180 degrees eliminates the surging is that the sensor picks up the triggers on the gear at the leading edge of the flat edge of the can sensor . When I rotate it 180 degrees I am moving the point that the sensor is reading . He said that there is a tech service bulletin that explains the procedure . In effect by rotating the sensor I am tricking the sensor into compensating for the slack in the timing chain . Does anyone have acces to this service bulletin .

 

[i68k]

i believe thats why many people have switched to the metal type sensors, metal and magnets conform to the principles of electromagnetism. as far as finding the tsb, you will need to google it, i dont think we sticky them here. it is possible to have timing chain stretch or slack and get cam codes, im not sure if your chain is the problem, but cam and crank sensors are very common problems and cheaper to diagnose/fix. you can send a message to shortcut10, i know he works at a dealership and will know more about the tsb.