2006 Pathfinder: trouble starting when cold

nissan
pathfinder

#1

2006 Nissan Pathfinder
153K miles
Remote starter installed

Toady it was 22 degrees outside in the morning.
I tried to start the car: cranked 1/2 second as usual, not even thinking - no start.
Not turning ignition off, simply making a second attempt, this time around 3-4 seconds cranking - no start.
Turned ignition off, waited 5 seconds -> started in 1/2 second, as usual, stable idle and good performance when driving.

Getting car remotely started over cold days before - sometimes it would not be running by the point I get outside, so considering that remote started is doing 3 attempts, increasing crank time by 1/2 second every next time (0.5 / 1 / 1.5 sec) - looks like today is not the first time it happens. Initially I though remote’s signal did not get to the car, apparently it was not the case.

When temperature is above the freezing point - never have this problem.

Car operates just fine: warms up to operating temperature in under 2 miles, then has 16 MPG in city cycle, which is normal for this gas hog.

Previous maintenance included new NGK Iridium plugs, cleaned injectors, new PCV valve, all new A/F and O2 sensors, new cats on bank-1, new air filter in last 2000 miles.
Had compression checked when worked on other repairs: solid 190-195 PSI all cylinders.

Any ideas what can cause this “delayed start” ?


#2

The next morning when you go to start the engine, turn the ignition switch to the on position so the dash lights come on for two seconds, and then turn the ignition switch off.

Repeat this a half dozen times, and then try starting the engine.

If the engine starts right up, it points to a problem with the anti drain-back valve on the fuel pump assembly.

Tester


#3

you may be right !!

when I was removing fuel injectors rail to clean/calibrate injectors, I was surprised I had absolutely no fuel pushed from the tubing, so likely it is the cause

other than inconvenience, this problem seems innocent enough, is it ?


#4

Innocent as long as anyone who uses the car is aware of the need to do the key dance.

You may find it less necessary in warm weather and with a gas tank that’s not low on fuel.


#5

yes, incidents seem to correlate to outside temperature falling, likely causing a reduced vapor pressure from the tank


#6

I think the above diagnosis is correct. This can be shop-verified by a fuel pressure leak down test. The fuel rail is supposed to hold pressure even when the engine is turned off, sort of like a balloon stays inflated for a week or so. It will always leak a little of course; the leak down test tells you if the balloon is leaking too fast. The injectors can leak too, but that is less common reason for a failed fuel rail leak down test.


#7

I know it leaks to zero pressure almost instantly. When I was removing high-pressure pipe before: it had zero pressure in half an hour after engine shutdown.

Now I will wait until weather improves, scratching my head if I really want to go into dropping off a fuel tank myself or getting some shop to do it.


#8

You’re probably right to guess it is the parts in the gas tank that’s the problem. But it still might be a leaky fuel injector. It would bea shame to go to all that work and find out that’s not the problem. Maybe somebody here knows otherwise, but I’m not aware of any method to test if it is the injectors leaking or not, other than removing the injectors from where they seat , pull them out, pressuring the fuel rail, and looking at the tips to see if the are leaking.


#9

good perspective, George…

probably what can be done:

  • get fuel line disconnected from the rail
  • get some stopper on the line
  • pressurize
  • check in an hour or so if fuel gets out under pressure once stopper is removed

now I have to invent what to use as a stopper…


#10

To check for leaking fuel injectors/fuel pressure regulator, locate the rubber fuel line between the steel fuel line and engine.

With a pair of hose pinch off pliers,

https://www.otctools.com/products/10-inch-hose-pinch-pliers

turn the ignition switch on so the fuel pump runs and then squeeze off the rubber fuel line with the pliers.

The fuel injectors are now isolated from the fuel tank.

Tester