Engine Performance problem
2004 Nissan Sentra 4 cyl Front Wheel Drive Automatic 77000 miles
I bought this car a week ago and it runs really smooth but sometimes I have problems getting it started. I can't say that happen when it's cold or warm, because it can start perfectly all day and the other day it won't, When I can't get it started in the first try, I always get it on the third.
I did the Accelerator Pedal released position learning and the Throttle valve closed position learning and after that the car starts fine, the one I can't do (Don't know why) is the Idle Air Volume learning (the MIL doesn't blink as described in the manual). I have no codes. Can you help me please?
The timing is of utmost importance when carrying out the process.
Do you need any info on how to do it?
What manual are you using?
July, 10, 2009 AT 12:49 PM
HI, I'm using a clock but I'm not sure if i'm doing it right, the manual is the Nissan service and repair manual.
July, 11, 2009 AT 6:44 AM
I have the IAV learning porcedures here. Check if it is the same.
July, 11, 2009 AT 3:50 PM
It's the same procedure, anyway yesterday I crossed the border so I did a one hour line aproxx and the car was fine but when I shifted the car to Neutral at the Inspection booth and started to rev up and rev down, almost stalling, and in Parking the car stalled. When I took the Highway the car was doing fine but when I stopped and shifted again to Parking, the car went dead. I let it rest for 2 hours and then the car was doing fine in any position again, do you think is the Fuel Pump?
July, 12, 2009 AT 1:03 AM
Since engine was running well on the road and problem occurs only when stopped, it should not be the fuel pump. I would suspect the idling system is at fault and as no codes were recorded, the most likely cause would be idle air flow.
Your initial post mentioned that the problem was improved after doing the accelerator position relearn, I would suggest looking into this first.
It could either be a fault with the Mass Air Flow or Throttle Body.
Let us start with the throttle body.
Remove the air hose from throttle body and visually inspect the inner bore. If there are dirt accumulation, clean it and do relearn procedure and retest.
Spray some carb cleaner into the bore and any other ports in it. Let it soak for a while. Use a piece of clean rag and spray some carb cleaner onto it. Gently push onto the throttle valve and use the rag to scrub out any dirt accumulation. Spray some carb cleaner to clean and wait for the carb cleaner to dry out slightly.
Reinstall the air hose and restart to test. If the carb cleaner has not dried out yet, you might have difficulty starting. No worries about that.
July, 12, 2009 AT 1:34 PM
OK, I'll go to Autozone to get the Carb cleaner and I'll do what you adviced me, I'll let you know when I'm done. Thank you : o)
July, 13, 2009 AT 1:25 PM
Hi, I cleaned the throttle with carb cleaner and I also noticed that the hoses connected to the EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE (that's a long name) were connected in the wrong position, the engine was getting air for that situation, when I connected them correctly, the engine ran more smoothly. I think the problem was solved. Thanks, you saved me a $400 fuel pump
July, 13, 2009 AT 6:30 PM
You are welcomed and glad that your problem has been taken care off.
Yes, quite often when connecting hoses, reversely connecting them can cause problems which is never easy to resolve as it is easily missed.