D40 starts and stalls on incline facing up

[Azi]

Hi all,
my stx Spain yd25 216 k km auto doesn't want to start only on incline.
If I switch off ( warm engine ), she doesnt start. Had to roll back to level ground for it to start.
Drives well otherwise.
Appreciate all feedback/ thoughts

 

[Old.Tony]

Let's be clear: if you've gotten it started and you're driving along and come to a hill you need to climb, does the engine stall on the way up? If so, I'd suspect a problem with the fuel pickup in the tank.

If it's only when you try to start the car when it's facing uphill, there might be a couple of possibilities:

* Dirty/faulty SCV - try a bottle of injector cleaner (Liqui Moly Fuel System Treatment is good) first and see if it improves. Try other solutions before replacing the SCV - although it's relatively cheap, it's fiddly to get to (side of the pump).

* Fuel line restriction - this could be anything from a dirty fuel filter to actual crud (like algae) in the hose. Not so easy to spot, but removing the fuel tank line from the filter and from the tank side then blasting compressed air through it will sort it out pretty quick. Also check the pickup in the tank.

* Fuel line leak - you won't see diesel coming out, but air will be getting in. Usually also causes hard starts in the morning, but since yours only happens when it's facing uphill my guess is if it is a leak it's a minor one somewhere in the hose between the filter and the tank or in the water sensor fitting. I don't suspect this as much as I do the fuel line restriction.

 

[Azi]

only when switched off up hill . I get off to open the gates . Get back in she wont start. It first happened with !/4 tank. I drove to servo ( 5km trip ) come back and same thing. I replaced fuel filter a month back. Did Syd to Queensland and back.
I suspect SCV . Will try and replace tomorrow

 

[Azi]

Hi Tony, I took out the SCV and dismantled. I couldnt see anything wrong with it. However I swapped it with another Navara ( low kms ). She is normal now. starts etc. Somehow I dont believe its a scv fault.
No error codes before I changed the scv.
Im curious to know what goes wrong with SCV and why so many people are changing it.

 

[Old.Tony]

My own SCV became the cause of some hunting (engine revs rising then falling continuously over about 300rpm range). Injector cleaner worked for a while (Liqui Moly Fuel System Treatment) but when the mechanic pulled the SCV you could see vertical scarring on the sides. I don't know what caused it.

It's not an uncommon issue and has been a diagnosis nightmare because sometimes it shows classic symptoms and other times it doesn't. Had the opportunity to meet a forum member who was having the "classic" symptoms (put foot down over 50% throttle, RPM exceeds 2,000 and boom, insta-limp). We loosened his fuel cap and the problem went away, until the fuel cap was tightened again.

I'd suggest that the tolerances in the system for a fault in the SCV are fairly low, which may be a poor design choice by Nissan (Renault) but it's something we just have to live with. They're not going to fix my 11.5 year old car by redesigning its fuel system and replacing it for me!

 

[Azi]

So Far she is running fine ( it was before as well ) . I strongly feel it had air in system.
Will post if problem happens again,
Thanks Tony . Regards