Fuel pump failing?

[bringthenav]

I have a issue where when going up hills after coming to a stop the engine seems to shudder for a minute.. suspect from a lack of diesel being pumped thru on time.

When moving off its got a bit worse lately, where i might need to pump the accel a few times to juice it up enough to move off smoothly.

Its generally fine while driving around. Was blowing lot of black smoke under serious load or going up hills. Egr blocked temporarily for testing purposes until i buy a whole new egr & now not seeing much smoke anymore like it cleared alot of the gunk in the motor out. Truck goes much better also. Fitted a catch can.
And a 9 drive. Much less smoke, much more power, much smoother ride. Idles perfect.
Always did. But this odd fuel issue remains.
300,000 high km motor.

Was getting limp modes, found i had slight loose intercooler etc clamps while fitting a boost gauge. Tightened all pipes up.
The limp mode went away!

I was stoked, but after week its back! But for a different reason.
I had a limp mode come on going up a freeway hill and luckily had free lanes to pull it over.. so i dont want that to occur again as it was very dangerous big issue to have so randomly at 100 on a freeway.

Thinking i have a bad fuel pump..!?
Hoping thats all it is!?

Few things i have noticed:

*Bit of diesel seepage around one the injectors? on top the rocker cover.

*Diesel Primer bulb noticed being soft at various times.. does usually always start A- OK.. might have been a case of low fuel other day, fuel light on (not past empty) then filled it, maybe going up some hill with the fuel temporarily tipping back caused a small amount of air in the tank-primer? thats caused the limp mode.

*When i was pulled over broken down i couldn't restart the truck, itd just turn over but not fire up

*After a couple minutes i tried it again and it started up

*Limp mode again later that day, this time at 60kmh.

*That night primed up the primer bulb a few times til it was solid, smelt a slight diesel smell on my fingers after.. not sure if thats normal? .. probably is.

*Now the truck fires up super fast and smoother immediately on keyturn & haven't had a limp mode happen again, seems to drive better and smoother too again.

*But yet the issue after going up any hills when coming to a stop remains,
It can be sluggish when moving off, then suddenly start hauling ass, as if juice wasnt getting thru quite enough. Its not intermittent, pretty much occurs everytime after any hill or being under load then coming to a stop, or anytime I'm off accel between gear changes uphill.

I am not getting any Cel codes come up by the way.

One of the following would likely solve it, though i am low and time and moneys not too good either to go and do all the following currently, so i really would want to nail the exact issue & replace all the other stuff in order asap.

What do people think?

Fuel pump ?
Pressure control valve ?
Suction control valve ?
Something else ?

 

[Old.Tony]

Hi, if you're getting diesel on your fingers while priming, then your primer bulb probably has cracks in it.

 

[BarneyB]

I have a issue where when going up hills after coming to a stop the engine seems to shudder for a minute.. suspect from a lack of diesel being pumped thru on time.

When moving off its got a bit worse lately, where i might need to pump the accel a few times to juice it up enough to move off smoothly.

Its generally fine while driving around. Was blowing lot of black smoke under serious load or going up hills. Egr blocked temporarily for testing purposes until i buy a whole new egr & now not seeing much smoke anymore like it cleared alot of the gunk in the motor out. Truck goes much better also. Fitted a catch can.
And a 9 drive. Much less smoke, much more power, much smoother ride. Idles perfect.
Always did. But this odd fuel issue remains.
300,000 high km motor.

Was getting limp modes, found i had slight loose intercooler etc clamps while fitting a boost gauge. Tightened all pipes up.
The limp mode went away!

I was stoked, but after week its back! But for a different reason.
I had a limp mode come on going up a freeway hill and luckily had free lanes to pull it over.. so i dont want that to occur again as it was very dangerous big issue to have so randomly at 100 on a freeway.

Thinking i have a bad fuel pump..!?
Hoping thats all it is!?

Few things i have noticed:

*Bit of diesel seepage around one the injectors? on top the rocker cover.

*Diesel Primer bulb noticed being soft at various times.. does usually always start A- OK.. might have been a case of low fuel other day, fuel light on (not past empty) then filled it, maybe going up some hill with the fuel temporarily tipping back caused a small amount of air in the tank-primer? thats caused the limp mode.

*When i was pulled over broken down i couldn't restart the truck, itd just turn over but not fire up

*After a couple minutes i tried it again and it started up

*Limp mode again later that day, this time at 60kmh.

*That night primed up the primer bulb a few times til it was solid, smelt a slight diesel smell on my fingers after.. not sure if thats normal? .. probably is.

*Now the truck fires up super fast and smoother immediately on keyturn & haven't had a limp mode happen again, seems to drive better and smoother too again.

*But yet the issue after going up any hills when coming to a stop remains,
It can be sluggish when moving off, then suddenly start hauling ass, as if juice wasnt getting thru quite enough. Its not intermittent, pretty much occurs everytime after any hill or being under load then coming to a stop, or anytime I'm off accel between gear changes uphill.

I am not getting any Cel codes come up by the way.

One of the following would likely solve it, though i am low and time and moneys not too good either to go and do all the following currently, so i really would want to nail the exact issue & replace all the other stuff in order asap.

What do people think?

Fuel pump ?
Pressure control valve ?
Suction control valve ?
Something else ?

How old is the fuel filter?
First thing I'd be changing. If it's got more than one, change both.

If you're driving around with bugger-all fuel in the tank & putting the boot into it up a hill, you might be gulping air & causing the loss of power?
The other day I was pushing my luck with the fuel light and it started to "miss" a little at the top of a hill right before the servo.

If it's an automatic trans car and it shudders as you move off it could be solenoid or torque converter related....

If it's a manual trans car and it shudders as you move off it could be DMF or clutch plate wearing out...

Disconnect the throttle controller while you're diagnosing. It just muddies the water.
(if you suspect the TPS signal is going bad you can watch the signal as a trace on the torque app via OBD2)

Rocker cover seepage around the injectors is usually lube oil getting past the rubber grommets in the cover. If it's fuel it'll be around the rail & the HP lines between the rail & the squirters.

Sometimes random limp symptoms can be caused by intermittent rail pressure relief valve failure. There's a process to test the valve to make sure it's not lifting early....search the forum....I think it's on here somewhere.

Anytime you go near the filter, the fuel tank cap, the primer bulb, the pump at the servo, the Navara itself......your hands get a slight smell of diesel.
So unless you've got fresh, wet diesel on the bulb I wouldn't read too much into it. But as Tony mentioned, the bulbs do get old & crack so have a good look at it.

Could be sticky SCV. You can throw some fuel conditioner/injector cleaner at it (yes, those additives do work) ...or remove the SCV & inspect.

The HP pumps on modern CR turbo diesels like ours are incredibly robust & pump failures are rare. Most pumps outlast the engine.
Pump failures are usually either just bad luck (1 in a 1000 scenario) or you've accidentally fed it a lot of petrol or water.

Check and double check all vacuum lines if it's a pre-2010 YD25.

EGR - maybe causing the issue but it doesn't really fit in my mind. I don't have much experience with troubleshooting EGR issues because I removed mine completely.
I know the ECU will throw a code if it's not happy with the EGR on the later models (from 2010 onwards I think?)

HTH.
Please reply when you have solved the issue so we can all benefit. There's far too many posts on here asking for trouble shooting help with no follow-up when the issue is fixed.

 

[bringthenav]

Hi, if you're getting diesel on your fingers while priming, then your primer bulb probably has cracks in it.

Thanks. I think it was actually coming from the fuel filter above it,
Which is new.. well last Sept.
10,000 ish old at best.

I notice the primer bulb soft every time though, ive pumped it up before every drive last week & seemed to help me not go into limp & the car went alot better.

Other day I noticed the fuel filter drain valve round thing was slightly loose ! So i hand tightened it up a bit more as much as i could.

Might been getting slight seep out the o-ring on that.

Primed up the primer. Had a few drives, havent primed it in few days, hasn't limped again. Touch wood that solved that issue.

So i think the slight diesel smell, slight dampness was coming from that & not the primer.

As usual when i open the bonnet next, i imagine the primers still going to be soft which isnt right is it?

I bought a new one off ebay to replace with, hopefully its a decent part.. cant see why not, fingers crossed.

Will swap it & prime it up and test that new one (and keep the old one on hand as its oem & might be nothing wrong with the old one)

 

[bringthenav]

How old is the fuel filter?
First thing I'd be changing. If it's got more than one, change both.

If you're driving around with bugger-all fuel in the tank & putting the boot into it up a hill, you might be gulping air & causing the loss of power?
The other day I was pushing my luck with the fuel light and it started to "miss" a little at the top of a hill right before the servo.

If it's an automatic trans car and it shudders as you move off it could be solenoid or torque converter related....

If it's a manual trans car and it shudders as you move off it could be DMF or clutch plate wearing out...

Disconnect the throttle controller while you're diagnosing. It just muddies the water.
(if you suspect the TPS signal is going bad you can watch the signal as a trace on the torque app via OBD2)

Rocker cover seepage around the injectors is usually lube oil getting past the rubber grommets in the cover. If it's fuel it'll be around the rail & the HP lines between the rail & the squirters.

Sometimes random limp symptoms can be caused by intermittent rail pressure relief valve failure. There's a process to test the valve to make sure it's not lifting early....search the forum....I think it's on here somewhere.

Anytime you go near the filter, the fuel tank cap, the primer bulb, the pump at the servo, the Navara itself......your hands get a slight smell of diesel.
So unless you've got fresh, wet diesel on the bulb I wouldn't read too much into it. But as Tony mentioned, the bulbs do get old & crack so have a good look at it.

Could be sticky SCV. You can throw some fuel conditioner/injector cleaner at it (yes, those additives do work) ...or remove the SCV & inspect.

The HP pumps on modern CR turbo diesels like ours are incredibly robust & pump failures are rare. Most pumps outlast the engine.
Pump failures are usually either just bad luck (1 in a 1000 scenario) or you've accidentally fed it a lot of petrol or water.

Check and double check all vacuum lines if it's a pre-2010 YD25.

EGR - maybe causing the issue but it doesn't really fit in my mind. I don't have much experience with troubleshooting EGR issues because I removed mine completely.
I know the ECU will throw a code if it's not happy with the EGR on the later models (from 2010 onwards I think?)

HTH.
Please reply when you have solved the issue so we can all benefit. There's far too many posts on here asking for trouble shooting help with no follow-up when the issue is fixed.

Thanks Barney for that whole bunch of info! Thats alot to take in
Where do i start to reply!
Thanks, well...

Fuel filter still new-ish late last year, maybe Sept.
Prior to fitting i used injector cleaner & fuel sys cleaners a few times.
That seemed to help somewhat.

Ive used them again recently & its seemed to help alot.

I keep seeing the primer bulb soft.
I pumped it up last week before every drive & the car ran better.. usually...
As if it was getting better fuel pressure and was heaps more effortless at the accelerator to drive.

Despite that, every time i opened the bonnet the primer bulb was soft.

I also had a couple random limps.
Even without it doing it with the usual but of a bootfull when it normally may happen.

I saw a post here about someone saying o-ring on fuel filter can be leaking...

I checked for that as i suspect the very slight dampness & diesel smell after priming it was coming from there.

Sure enough the round dial itself seemed to turn to the right when i applied a little pressure.

I read how to posts before installing that fuel filter myself..
So i would have done the o-ring tightening & whatever procedures to it while fitting the filter correctly as far as i know.

Sure enough it seemed to turn under hand pressure & the diesel smell and slight dampness appears to actually be coming from there.
More so than the primer which us under that as u know.

I have tighten the fuel filter round dial hand tight, quite a bit, clockwise,
Without overtightening and potentially snapping and breaking something. Its probably not completely tight...
but is alot tighter.

I primed it up, still damn well soft primer every time i try it
Which hardens after a few pumps.

So i primed it up & went for a few drives for close to a week now..

Havent had any more limp modes
(I better touch wood! And keep my fingers and toes crossed)

Possibly this round filter dial seeping slightly might been contributing to my issue. Could air have been getting in there slightly & causing some air in the fuel system.. i dont know,
But so far the cars been going okay unchecked & unprimed for a few days, and hasn't limped on me.

I have tipped a bit of Lucas injector cleaner suitable for diesel in when filling up at least $50-60 diesel a couple times & it seems to like it.

Soon i'll check & use maf cleaner to clean the electric connector for the fuel pressure sensor.

I'll get my mechanic to check the injector rocker cover seepage whatever that is when he services the car & run his professional scan tools etc etc etc, i notice the electric connectors on a couple the rocker cover i assume is the injectors.. (on top) sorry first Navara ive had, i am learning alot about these motors and vehicles though.. (not really by choice).. well i notice one the connectors is badly coated with the sludge thats seeped out the rocker under it, which after reading your reply, i guess i should suspect thats oil ... And not diesel as i said before.

I'll get him to clean that wiring plug, as well as the other 3 while at it.
With any luck that will solve my whole issue.

So in a nutshell theres lots of little issues could be contributing,
Needs lots of service and bit TLC,
and that seepage and being on the electric connector is the most obvious problem i can actually see..
So sorting it out so it doesn't seep any longer from under the injector round port & cleaning all the electric wiring looms should help & if i am lucky i will solve the whole issue.

 

[bringthenav]

Yes, i will disconnect the 9 drive throttle control thing before diagnosing..

Yes i will update the post if and when i solve all issues & provide info how it was done.

I agree, its always helpful when people actually follow up their post after they solve things... For the benefit of everyone else.

I have attached some pics of the seepage

 

[Mark1902]

I have a issue where when going up hills after coming to a stop the engine seems to shudder for a minute.. suspect from a lack of diesel being pumped thru on time.

When moving off its got a bit worse lately, where i might need to pump the accel a few times to juice it up enough to move off smoothly.

Its generally fine while driving around. Was blowing lot of black smoke under serious load or going up hills. Egr blocked temporarily for testing purposes until i buy a whole new egr & now not seeing much smoke anymore like it cleared alot of the gunk in the motor out. Truck goes much better also. Fitted a catch can.
And a 9 drive. Much less smoke, much more power, much smoother ride. Idles perfect.
Always did. But this odd fuel issue remains.
300,000 high km motor.

Was getting limp modes, found i had slight loose intercooler etc clamps while fitting a boost gauge. Tightened all pipes up.
The limp mode went away!

I was stoked, but after week its back! But for a different reason.
I had a limp mode come on going up a freeway hill and luckily had free lanes to pull it over.. so i dont want that to occur again as it was very dangerous big issue to have so randomly at 100 on a freeway.

Thinking i have a bad fuel pump..!?
Hoping thats all it is!?

Few things i have noticed:

*Bit of diesel seepage around one the injectors? on top the rocker cover.

*Diesel Primer bulb noticed being soft at various times.. does usually always start A- OK.. might have been a case of low fuel other day, fuel light on (not past empty) then filled it, maybe going up some hill with the fuel temporarily tipping back caused a small amount of air in the tank-primer? thats caused the limp mode.

*When i was pulled over broken down i couldn't restart the truck, itd just turn over but not fire up

*After a couple minutes i tried it again and it started up

*Limp mode again later that day, this time at 60kmh.

*That night primed up the primer bulb a few times til it was solid, smelt a slight diesel smell on my fingers after.. not sure if thats normal? .. probably is.

*Now the truck fires up super fast and smoother immediately on keyturn & haven't had a limp mode happen again, seems to drive better and smoother too again.

*But yet the issue after going up any hills when coming to a stop remains,
It can be sluggish when moving off, then suddenly start hauling ass, as if juice wasnt getting thru quite enough. Its not intermittent, pretty much occurs everytime after any hill or being under load then coming to a stop, or anytime I'm off accel between gear changes uphill.

I am not getting any Cel codes come up by the way.

One of the following would likely solve it, though i am low and time and moneys not too good either to go and do all the following currently, so i really would want to nail the exact issue & replace all the other stuff in order asap.

What do people think?

Fuel pump ?
Pressure control valve ?
Suction control valve ?
Something else ?

Having problems with my D22 yd25 also.
Won't accelerate over 3000rpms when under load.
Changed fuel filter and now can't prime engine..

 

[hotshot 5691]

I have a issue where when going up hills after coming to a stop the engine seems to shudder for a minute.. suspect from a lack of diesel being pumped thru on time.

When moving off its got a bit worse lately, where i might need to pump the accel a few times to juice it up enough to move off smoothly.

Its generally fine while driving around. Was blowing lot of black smoke under serious load or going up hills. Egr blocked temporarily for testing purposes until i buy a whole new egr & now not seeing much smoke anymore like it cleared alot of the gunk in the motor out. Truck goes much better also. Fitted a catch can.
And a 9 drive. Much less smoke, much more power, much smoother ride. Idles perfect.
Always did. But this odd fuel issue remains.
300,000 high km motor.

Was getting limp modes, found i had slight loose intercooler etc clamps while fitting a boost gauge. Tightened all pipes up.
The limp mode went away!

I was stoked, but after week its back! But for a different reason.
I had a limp mode come on going up a freeway hill and luckily had free lanes to pull it over.. so i dont want that to occur again as it was very dangerous big issue to have so randomly at 100 on a freeway.

Thinking i have a bad fuel pump..!?
Hoping thats all it is!?

Few things i have noticed:

*Bit of diesel seepage around one the injectors? on top the rocker cover.

*Diesel Primer bulb noticed being soft at various times.. does usually always start A- OK.. might have been a case of low fuel other day, fuel light on (not past empty) then filled it, maybe going up some hill with the fuel temporarily tipping back caused a small amount of air in the tank-primer? thats caused the limp mode.

*When i was pulled over broken down i couldn't restart the truck, itd just turn over but not fire up

*After a couple minutes i tried it again and it started up

*Limp mode again later that day, this time at 60kmh.

*That night primed up the primer bulb a few times til it was solid, smelt a slight diesel smell on my fingers after.. not sure if thats normal? .. probably is.

*Now the truck fires up super fast and smoother immediately on keyturn & haven't had a limp mode happen again, seems to drive better and smoother too again.

*But yet the issue after going up any hills when coming to a stop remains,
It can be sluggish when moving off, then suddenly start hauling ass, as if juice wasnt getting thru quite enough. Its not intermittent, pretty much occurs everytime after any hill or being under load then coming to a stop, or anytime I'm off accel between gear changes uphill.

I am not getting any Cel codes come up by the way.

One of the following would likely solve it, though i am low and time and moneys not too good either to go and do all the following currently, so i really would want to nail the exact issue & replace all the other stuff in order asap.

What do people think?

Fuel pump ?
Pressure control valve ?
Suction control valve ?
Something else ?

Here's what I did.

Drop your tank then clean out pickup intake strainer. Make sure tank is empty otherwise it's like a full coffin.

 

[bringthenav]

That issue seems to have largely gone away after heaps of other TLC inc diesel fuel treatment again, turbo cleaner treatment, few full to brim tanks.. blowing a bit of gray-white smoke still esp after getting below half full. Probably is alot of crap in this 316,000km old tank.

Worth doing someday soon for sure anyway