Just joined here after picking up an extremely clean and well-maintained 2002 Pathfinder LE with AllMode 4WD and 102k miles to replace my girlfriend's 2001 Pathfinder LE 2WD with 229k miles (which will be for sale soon). The 2002 runs strong and smooth, but there's an issue with delayed starts only when warm. It fires right up when cold or hot, but if it's been sitting for a few hours, it takes several seconds of cranking before it fires up. I can cycle the key to get it to start quicker, or let the key stay in the On position before starting it. All of this points to fuel pressure dissipating prematurely during cooldown. I read several Nissan V6 posts online that describe this problem but there are usually other symptoms either of a failing Fuel Pressure Regulator (hesitation or lack of power), Fuel Pulsation Damper (ticking noise), or Fuel Pump Check Valve (hard starts when cold). Once it starts, it runs great, and fuel mileage when I checked was 18.8 MPG on a tank of mostly highway miles and 17.5 mixed driving. I removed the vacuum hose at the FPR and got a strong fuel smell but no sign of dampness. I removed the vacuum hose at the Pulsation Damper and also got a fuel smell without dampness, maybe less strong than at the FPR. There's a ticking noise only when cold that the 2001 doesn't make but it goes away after a couple minutes of warm up. I'm inclined to replace the FPR since it's easy and not expensive, but wanted to see if anyone has a definitive solution. Thanks!

This is a semi common issue. Start by checking the gas cap. Heat the vehicle up and turn it off and remove the cap. Does it whoosh an excessive amount of air? Also...the evap system can cause these issues. Check the charcoal canister and egr system

I bought 2002 QX4 new. During nearly 17 years I have had maybe three times of not being able to start the engine, including today: Turned the key to start the engine but absolutely no click, no other sound at all. Shifted into some other gears and back to "P", no help with starting. I know battery is about two months old but wanted to check if it was discharged. Got the meter and measured 12.4 V. Put meter back in office and came out to start the engine. It started normally like nothing happen a couple of minutes ago.

Since it happened very rarely I don't remember when was last time it happened, only remember it was exactly the same way. I am just guessing the ignition switch has got dirty contacts.

Anyone has the same experience? Thank you all for reading my post.

Make sure you are using a genuine Nissan key. I had this happen on my 2002 pathfinder. I noticed it only happened when the spare key was used. Haven’t had this issue since using the Nissan key.

I remember arming the alarm and disarming the alarm and that would work too.

Mine sometimes whooshes and sometimes stumbles on warm start. What could be causing this? Gas cap not relieving pressure (isn't pressure supposed to stay in the system and be purged?) Bad vent valve?

heavy hitter wrote: ↑

Tue Apr 16, 2019 8:33 pm

This is a semi common issue. Start by checking the gas cap. Heat the vehicle up and turn it off and remove the cap. Does it whoosh an excessive amount of air? Also...the evap system can cause these issues. Check the charcoal canister and egr system

rgk wrote: ↑

Wed Dec 28, 2022 9:26 pm

Mine sometimes whooshes and sometimes stumbles on warm start. What could be causing this? Gas cap not relieving pressure (isn't pressure supposed to stay in the system and be purged?) Bad vent valve?

Warm start stumbles are typically a fuel delivery issue with suspects like a leaking fuel regulator feeding its vacuum line, a weak fuel pump, and dirty fuel injectors. If there was any issue with any of the valves in the EVAP system, you would get a flashing CEL for some sort of DTC being flagged. The "woosh" sound when opening the gas cap is typically a vacuum noise, not positive pressure, and it is typically normal. I get more or less of that vacuum relief noise when I remove my gas cap depending on how full my tank is. There can be exceptions with anything too excessive but there would be a DTC with most anything that is.

Curious to see what heavy hitter writes, if still around. My whoosh is sometimes excessive. Injectors are recently cleaned. FPR is new. I guess I'll check the cap and the canister and maybe the vent valve and damper too. For the record I got a pending 1491 when car wouldn't start one time. Cut valve is used for EVAP diagnosis, I wonder if I'm getting the code due to sticky vent valve. Cut valve check valve is new. It would be nice to have an overview how to troubleshoot the entire EVAP system. I'll probably just look at the FSM eventually, it might be in there.