Quote:
Originally Posted by Tom_O370
But if the car sits for 30 minutes to 2 hours after being driven, it takes a few seconds to turn over and when it does its very hesitant in doing so. Also, i want to mention that after being started, then turned off, and started again, it will start right up. !
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Is the cranking speed the same in each example?
As for fuel pressure, her is what I have measured from my 2011 G37 last month:
• When the engine is turned off it drops to about 46 PSI from 51 PSI with the engine running.
• After 30 minutes: 45 psi
• After 1 hour: 30 psi
• After 2 hours: 16 psi
• After 3 hours 9 psi
•*After 4 hours 4 psi
• After 5 hours < 1 psi
(This was measured using a Honeywell 100 PSI pressure sensor with CJ Motorsports 2 port fuel tap and my data logger sampling once per second)
There is a TSB (EC07-016A) for the Nissan Versa and it mentions that fuel system pressure needs to be > 29psi after 30 minutes from when the engine is off.
Since that fuel system is very similar to ours (51 psi), I suspect it is a good rule of thumb.