Please help - poor performance after filter change - SOLVED

[arrowkarts18]

hi all your help would be muchly appreciated, i have recently just purchased a new (genuine) fuel filter from nissan for a 2007 spanish built navara d40 2.5 manual. i fitted it today primed her up and she started no worries. i then took her for a drive and suddenly huge loss of power. i have a boost gauge fitted and for some reason it seems like the turbo aint even working or anything, this may be limp mode im notsure? it hardly revs and the engine itself sounds alot louder than usual. i have tried resetting ecu using the procedure and i cant seem to get it to work no codes come up or anything. so i then tried disconnecting the negative terminal from the battery and switching on the ignition to reset the ecu and also put the brakes on to drain excess power. i then hooked battery back up started her and went for a drive and still same problem no power at all no turbo coming in louder engine noise etc. i have been reading numerous forums about fuel filter changes but cant seem to find much people in my position. i believe there could be air in the fuel lines but unsure. also i put old fuel filter back on just to check it wasnt the new fuel filter and still the same problem. please guys anything you may know that could help would be greatly appreciated. cheers

 

[grasshopper]

Did you fit the two "O-rings" ?
As per the very recent post by someone about the fuel filter replacement procedure.

 

[Old.Tony]

Welcome to the forum.

Okay first things first - let's check for air in the fuel line. Pop the bonnet and reach under for the primer bulb and count the squeezes until it gets hard (I am talking about the car). Under 6 squeezes = good, it isn't air. 6 or more squeezes you may have a leak.

If you find it's got a leak: the inner seal in the fuel filter is the finickiest bloody thing on the planet. I can't believe that they designed something that could cause so much grief - but there you are. Disassemble the filter, check that the seal is in place and perfectly clean then reassemble carefully. Reprime & test drive it. It might NOT be the seal - it could be the hose clamps are too tight (pinched hose = leaks). It could be a hardened/cracked hose = leaks. Could also be a loose hose clamp = leaks. It's all on the suction side so you'll never see diesel coming out, but it'll suck like a Dyson.

If there's no evidence of an air leak, I'd check the turbocharger actuator. The vacuum pump is down near the oil filter (below the fuel filter) and the vacuum hoses run up and over the motor. It's an easy thing to dislodge them. They can also be suffering from heat and age and may be easy to turn on their barbs or may be cracked or split. This will prevent the turbocharger from being used properly and will definitely provide the symptoms you have described - you should see a large amount of black smoke on an attempted hard take-off.

Try that, there's more to think about too so don't despair.

 

[kernels]

If you just replaced the fuel filter you also want to do a ECU reset, it is possible that you could have gone into limp mode if your rail pressure was suddenly much higher than the ecu expected due to the new filter, but if that were the case you probably would have had a CEL.

 

[arrowkarts18]

solved!

Thank you all so much for the quick responses, the problem ended up been the vacuum line that runs from the turbo to the engine it was completely snapped off. Silly me has obviously knocked it as I pulled the old filter out. So old.Tony you hit the nail on the head mate you where a great help thank you all cheers.