Air in Fuel Line

[Nat]

Hey guys,

Car/ Navara rookie here. Bought a D40 2008 Navara and trying to get it on the road. It starts fine, but when it's cold it blows a lot of black smoke when pushing on the accelerator, and it loses power and stalls randomly. Once it's warm, runs beautifully.

Had the fuel and air filters changed, had the MAF sensor cleaned and decided to look at the SCV. The car has apparently been sitting around for about a year before we got it, so thought the bad fuel could be the issue.

Anyway, managed to take out the SCV and clean it with some carby cleaner. In the process, we stupidly unclipped a nearby hose which happened to be diesel. Connected it all back up and started the car. It ran for about 15 seconds then cut out, and sure enough wouldn't start again (would try but not turn over). Figured it wasn't getting fuel, after a bit of head scratching realised that we would have put a massive bubble in the fuel line when we disconnected that hose.

Any idea how to fix this? Do we prime the fuel using the primer on the top of the fuel filter? Or do we need to disconnect that hose again, prime it until the fuel starts flowing and reattach?

Thanks!

 

[Old.Tony]

Prime the fuel system with the bulb that's in the fuel line near the filter. That should get the fuel back into the pump.

Thinking about the black smoke issue - if it happens only when it's cold then it could be one of two things:

1) Faulty EGR valve. This one's easy to "rectify". Undo the two 12mm bolts that hold the EGR tube to the valve on the vehicle's right hand side and remove the gasket. Make a copy of this gasket out of 1mm stainless steel but conveniently forget to cut the large hole out of the centre. Reinstall with gasket cement (Permatex Ultra Blue is a good choice). The 2008 car does not have any flow sensors so it will not throw any codes or cause any more problems.

2) Faulty turbocharger. This is harder. While it could be a vac hose that seals up properly once the engine bay gets warm, it's also possible that it's some gummy deposits inside the turbocharger's bearings which free up when the oil is hot. Removal and cleaning is the fastest way to resolve it, but you might need to install a bearing kit. Find out: if you remove the air hose from the front of the turbocharger you should be able to give the impeller a wiggle and a spin. If it wiggles it's possible that the impeller has touched the housing (see below) and this will require a replacement turbo. If there's no wiggle, but it's really quite reluctant to turn, the bearings are gummed up. If it spins reasonably freely (remembering that there's cold oil in there, so there will be some resistance) then the turbo is fine.

Impeller touching the housing: easy to tell if this has happened without disassembly of the turbo. Remove one end of the rubber hose that connects from the baffle on the side of the motor near the turbocharger to the intercooler. Wipe a fingertip inside this, picking up the oil. Examine this oily residue under a bright light - if you see reflective particles, that's a sign the impeller is rubbing the housing. You'd need to replace the turbo bearings, casing and impeller = the whole thing.