GFB

Hi guys!

3 weeks ago I acquired a 2005 X-Trail 2.5 that appears to be in a very good condition (done 25 000 km). Unfortunately the vehicle does have a problem we are trying to sort out (still has to find a convenient time if I ultimately have to leave it with the dealer). I did search this forum and already found some useful comments, but just maybe somebody could help us arriving at the source of the problem quicker?

PROBLEM: Difficult to start when engine is already hot and some time has elapsed.

SYMPTOMS: Have to swing engine typically 6 times (or, 3 to 4 seconds). It then starts (sometimes with a momentary hesitation - almost stalling). Thereafter it will idle and run fine. The vehicle appears to pull/accelerates normal and fuel consumption also appears normal (10 L/100km average). Cold starts are always acceptable. The battery and starter motor swings the engine well. No warning light.

WHEN: If the engine was driven in normal fashion (say for 10-15 minutes) and has soaked for some time at normal operating temperature (more easily attained on a hot day). The problem is not evident if switched off for only a minute or 3 and then trying to start the hot engine. But, having waited for say 10 minutes, and then trying to start the engine, clearly shows the problem (quite consistently). Waiting for say an hour or two, again does not show the problem clearly.

So far I made a few short visits to the dealer (still under warranty) - the TB is clean, the spark plugs were changed, throttle/idle learning was performed, and a new MAF sensor was tried out.

1. My gut feel is it is a fuel pressure problem (especially after learning the vehicle has no fuel filter) but the service supervisor does not seem to think so. He also does not belief there is any chance of vapour forming in the fuel rail. Is there any non-return valve one can replace?
2. I read on this forum it could also be a faulty fuel relay (does somebody know what the resistance should be?).
3. Or, a bad crank position sensor? (but, should this not also affect running after starting?)
4. If it is a faulty throttle body, should it not also affect running after starting?

Thank you for any good advice or experience shared!

 

GFB

Some feedback – hopefully of some benefit to somebody having to face a similar problem in future.

I finally managed to find a suitable time to leave my XT with the dealer – for them to try and do some more thorough testing / fault finding. Having measured the fuel rail pressure they found it to fall away rapidly after switch-off. They think it is a faulty Fuel Pressure Regulator. It is a relative small, separate part (22670Z) fitting on top of the strainer that goes over the fuel pump (in the tank).

They claim this type of failure is extremely rare on the X-Trail…(now, why me?!) Still needs to be confirmed, though (i.e. after fitting the new one – have to wait for the part).

flynn

Hope you get it sorted GFB.

BTW, I don't think the lack of replies is due to a lack of interest, more that no one felt they had anything useful to suggest. Good luck when it goes in.

GFB

Great! - problem solved!! Everything went well; they received the part one day later after ordering. Had a courtesy car meanwhile.

I asked the mechanic to see the culprit part - to me it looks more like a non-return or check valve (rather than a "pressure regulator" as called on their parts list). About 15mm max diameter by say, 48mm long with 2 pipe connection ports.

My confidence is restored - can now enjoy the car!

Regards

golfer

That is great the problem is solved.

Thanks for the update.

 

Sean King

Thanks alot!!
I am experiencing this same problem to the exact complaint.I am going to let them check this Fuel pressure regulator first to see if it is the problem.

My problem occurs the same way with perfect start when its cold but when it warms up and you slow down and it goes into idle mode it will either stall or have an erratic idle way below zero on the tachometer and then it levels off but with a poor idle quality.

If you switch off engine when hot the vehicle will not start until you press the accelerator and then still the idle is very erratic.

Thanks again for your help and i will be getting them to check this Pressure regulator first.

GFB

Hallo Sean.

I'm afraid your problem sounds somewhat different to me... In my case the engine always ran & idled OK after being difficult to start (when warm). Because once running, the fuel pump could keep up with what got lost at the regulator. But who knows..., perhaps it is the same problem (just worse)?

Could be the MAF sensor or dirty throttle body. Also take note of my points 2, 3 & 4 in my original post. But, I would say let them 1st perform the "throttle/idle learning" routine - they do that quite easily by plugging in a computer device named "Consult-II". I belief this diagnostic tool may also show out a faulty sensor. Another easy thing to do is to check what the spark plugs are revealing.

So, at speed the engine pulls normal? and your fuel consumption appears to be normal?

Good luck and please let us know about the outcome.

Regards

LEONGSTER

You may have a leak in your air intake system that is causing the rough idle once the engine goes into closed loop. This sometimes throws up a faulty MAF sensor code.

Either that or a clogged PCV valve.

Check for leaks first, before performing the Pedal Position/ Throttle Reset/Idle Air Learning Program.