Hard to start then erratic idle?

JOE ELAM

MEMBER
2005 NISSAN ALTIMA
3.5L
V6
2WD
AUTOMATIC
140,000 MILES

This VQ35 is very hard to get started at times. Other times it's fine. When it does start it acts like it's hunting for time. RPMs are all over the place but eventually settle down. Car runs great otherwise. I've checked everything. I'm thinking the timing chains, but I don't really hear any clatter when on the throttle. Could it be fuel pressure leak down? Please help? Thank you in advance.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,755 POSTS

Hi,

If you are questioning fuel pressure drop-off, try this:

1) Turn the key from off to run (engine off) and count to 5.

2) Turn the key off and repeat step 1 a total of 5 times.

3) On the 6th time, see if it starts normally.

If there is no change, the next question I have is if the check engine light stays on when the engine is running.

If cycling the key does nothing, let's try the throttle closed and air volume learning procedures. I attached directions below. The first pic is specific to the throttle valve closed procedure. Do this one first. The remaining pics are specific to the air volume learning procedures.

Both of the procedures below don't require a scan tool. If you have one that can communicate and actuate the throttle body/PCM, let me know.

Let me know what you find. Also, let me know if you have retrieved any diagnostic trouble codes.

Take care.

Joe

See pics below.

Images (Click to make bigger)