Help - Navara in limp mode day after purchase

[Honeybee]

Hi there - in the last 2 days I've read heaps on this forum (thanks so much for the info). I've just bought a 2014 Navara ST-R (converted to a flat-tray), that's done 85K kms. It came down from QLD to Tassie with the seller so had to have a roadworthy after I agreed purchase. To pass the roadworthy the EGR plates were removed. I picked it up a couple of days later and first trip out it went into limp mode. No engine malfunction light or code. Re-blocking the EGR hasn't helped. Has removing the plates after 80,000kms upset some sensor or other? Feeling very miserable about my purchase at the moment

 

[Old.Tony]

Welcome to the forum.

It might be unrelated, like a fuel line issue (small leaks will allow air in, so you won't see diesel fuel leaking, but it'll cause problems). Does it stall or anything? Is there any smoke, and what colour? How much fluid is in the radiator overflow bottle? If you prime the fuel system about 15-20 times, does any diesel start leaking?

 

[Honeybee]

Hi Old Tony (on a side note I can't work out how to change my name here to something a little more anonymous ), I've already seen you are the fount of all knowledge . It only stalls if I don't carefully feather the clutch because the power and revs are so low and take so long to increase when I press the accelerator. No smoke. Engine looks clean as a whistle. Radiator full - checked that yesterday and there is some fluid in the overflow. All levels in other fluids look good. Don't know how to prime the diesel but I can look it up. Seems strange something like that could happen so suddenly though. I'm suspicious because when my old Colorado went into limp mode with no engine light, I tracked it to the EGR and when we gave it a really good clean, problem was solved. Local garage wanted to charge $1200 to replace it . EGR in Nav clean because was blocked both sides. Grateful for any help because at present I can't use it - we have lots of hills around us and live in rural area - I can barely get up our drive, let alone to a mechanic. Happy to do diagnostics/ work ourselves as much as poss.

 

[Old.Tony]

I'm not sure of the exact location of the primer in the 2014 D22, someone else will need to help there.

It certainly does sound like it's starving of fuel. Smoke would indicate not enough air (which is the same as too much fuel). EGR leaking would result in black smoke. If the turbo was not producing enough boost it would smoke as well.

 

[Damian m]

Primer is on the passenger side near the firewall with the filter under it.

 

[Honeybee]

Thanks Old Tony and Damian m, will go looking for fuel primer and any leaks/ trapped air. Have also disconnected batteries overnight to see if it's just an ECU hiccup. Have ordered EGR delete plug-in in case it's the EGR sensor. At least I've got things to try now so feeling far more heartened - thank you!

 

[BarneyB]

Any luck?
Which part of Tas are you located?

 

[Honeybee]

Hi Barney - no luck I'm afraid! We're in the Huon Valley, near Huonville. Disconnecting the batteries overnight didn't help (long shot). Also, can't find the primer for the fuel lines. I've identified the fuel filter and fuel lines but there doesn't seem to be a primer bulb anywhere ... Do you have any other ideas?

 

[Honeybee]

Hi there Damian - no luck finding a primer bulb, despite locating fuel filter and fuel lines and feeling all around filter and along the fuel lines. Not sure where else to look.

 

[BarneyB]

Hi Barney - no luck I'm afraid! We're in the Huon Valley, near Huonville. Disconnecting the batteries overnight didn't help (long shot). Also, can't find the primer for the fuel lines. I've identified the fuel filter and fuel lines but there doesn't seem to be a primer bulb anywhere ... Do you have any other ideas?

Checked the top of the fuel filter for a hand pump?

I was thinking if you were not too far from Launceston I'd drop by with my OBD scan tool & see if it's stored any codes. I know you said it hadn't triggered the CEL....but sometimes there is historic codes stored in the memory that serve as clues (sometimes not).
But Huonville (return) is quite the drive from Launnie (sorry, I'm a single Dad this month....time poor!)

Another simple check - follow the engine harness around and make sure every significant connection is secured/clicked in.
Cam sensor, MAF sensor, oil level/pressure etc etc.
Sometimes when someone has been working in the bay (like removing an EGR plate) a harness connector is either disconnected & then forgotten about (when the phone rings).....or accidently bumped. (ask me how I know).

If the local Nissan dealer are good people, they may be able to tell you each & every condition that triggers the limp mode...? Then you could rule out the weird unrelated stuff & check the likely systems?

 

[Honeybee]

Thank you Barney - yes the trip here and back to Launceston is an endurance test! OK, I've been looking for a bulb so I'll look for plungers/ levers/ hand pumps! The harness tip is a good one, will try that too. Cheers

 

[Old.Tony]

Jenny, check near the top of the forum display on the right hand side, there should be a little envelope to the right of your name, and it should have a number ... click on it for me!

 

[Honeybee]

Update: reset ecu, fitted EGR delete on MAF sensor, checked all connections, established that fuel filter wasn't changed at recent service, pumped primer on fuel filter and checked all hoses/ pipes for leaks. Still no change from limp mode. Video shows the issue. When I first try from cold, I can't get above 2,500 revs, when it's a bit warmer it gets to 3,000, but takes ages. Any more ideas gratefully received

 

[Old.Tony]

I wonder if the NPS is faulty.

I think it's a blue plug on the gearbox (can anyone confirm that?). Just unplug it, all it will do is remove the neutral position detection. In neutral, the engine is operated differently so that you can't overrev the engine or provide excessive boost when it's not needed. If the ECU is seeing "neutral" all the time, it'll do this protection thing all the time.

 

[Honeybee]

Ok, interesting - another thing to try, thank you

 

[Newnav100]

I wonder if the NPS is faulty.

I think it's a blue plug on the gearbox (can anyone confirm that?). Just unplug it, all it will do is remove the neutral position detection. In neutral, the engine is operated differently so that you can't overrev the engine or provide excessive boost when it's not needed. If the ECU is seeing "neutral" all the time, it'll do this protection thing all the time.

Easy way to check the NPS is flick the heat switch on in neutral. Then try putting it into gear. If the NPS is faulty the revs won’t drop

 

[gjr]

I have seen similar on vehicles with a blocked muffler

 

[Honeybee]

Didn't know I had a heat switch - ok thanks! I don't have high hopes because at present it's not only that it won't rev, but that there's a several seconds delay on the gas pedal. Put pedal to the floor and it's really slow to respond- takes 2 or 3 seconds to get past 1,000 revs ...

 

[Honeybee]

Ok thanks. Could that happen so suddenly? Driving great day or two before. Between me agreeing to buy it and getting it, it had a service, something lifted to stop the big wheels rubbing on bodywork, EGR plates removed and the Tas roadworthy inspection. I did one 50km round trip, then a couple of days later I go to use it and it's in limp mode.

 

[Honeybee]

When you pump the plunger on the fuel pump should you get to a point where you can't press it any longer? With mine I can pump it and it gets difficult to press, then a few mins later, I can pump it fairly easily again.