ZD30 CRD possible fuel starving loss of power problem with no codes

[R055IE]

Hi Bill,

Yes I changed the filter , it was clean , I pulled the tank out on Friday and it was spotless inside, I was hoping to find a rag stuck to the pick up or floating around....

I just went out and bled the filter to see if there was any air and I have noticed that the fuel bulb pump no longer gets firm after a couple of pumps ??

I took the outlet off the filter (hose to engine) and it is pumping good amounts of diesel when squeezed with no air present.

I hooked it back up and took the return off the filter and pumped the bulb but no return came through ??

The bulb doesn't firm up and I have no return ??

[Bidja]

Certainly do not rule out possible fuel issue.

With engine at idle is your actuator rod lifting and dropping all the way when you connect and disconnect vac hose at actuator?

Check and see if the electrical connector for the VNT vac solenoid is securely plugged in. CRD need this plugged in with manual boost control, DI do not.

[Bidja]

Maybe air trap.

FWIW

For me, previous fuel filter changes have had no problems, but the last filter change, the primer bulb would not come up firm. Was cranking with main battery and was quickly fading so paralleled up Aux. Only a couple attempts and decided not good.

Ended up removing both fuel tank filler caps and primed up by leaving larger filter metal outlet hose off and squeezed primer bulb letting the filter vent thru outlet pipe, then placed finger over the metal outlet pipe while letting the bulb expand to draw fuel into and thru filter (many pumps). Pressure in bulb came up when the filter was near full and when I had a visual of fuel put hose on, primed bulb further maybe 6 times and came solid. Glowed / cranked and eng started straight up and then pumped primer a few more times at idle and all was good there after..

[R055IE]

Hi All,

just went and took the black return valve thing off the top of the fuel filter and pumped diesel out of the filter through that hole , got a bit of air out, put it back together and have pressure in the bulb now.

Bidga, the connector is connected and the actuator rod is moving about 15mm

NOTE: this problem only started after I fitted the 3" exhaust , could of been a coincidence , maybe not ??

[Hodge]

NOTE: this problem only started after I fitted the 3" exhaust , could of been a coincidence , maybe not ??

Again, you mentioning this, it triggers possible overboosting , hence possible limp mode again. Larger exhaust obviously promotes more flow through the snail, hence more boost, which possibly triggers limp mode.
One of limp modes primary triggers is overboost. ZD30 crd are very sensitive to this...



However... You mentioned it played up idling this morning ??? When you say idling, you mean putting along slowly out of driveway?

[R055IE]

Hey Hodge,

The boost is now set at 15psi.

I am onsite now but the problem happens straight after start up as you go to drive out of the carpark, it doesn't matter about the rev range, the speed, the gear or the terrain , it just does it

[Bidja]

@R055IE

As you got a solid primer bulb "Pump it at idle" several times to purge a bit.

As Bill @BillsGU, suggested clean you boost controller (Tillix/Dawes).

Try your testing with you needle valve fully closed, CRD can handle max spool.

If still no joy we can isolate manual boost control and run actuator direct off vac line. Hold off on this at this stage, need to very careful not to overboost.

What boost gauge U have and what is the max scale reading?
What max boost or bounce are you getting with quick full pedal with slight eng load (say 40-50%)?

Out of interest, have U blocked your EGR?

[R055IE]

Hi All,

I pumped the bulb at idle, pulled the boost controller apart (all clean) and reset to 15psi, closed needle valve and went for a drive.

No throttle response at all , dead pedal , zero boost , reset needle valave and still no throttle response, dead pedal, zero boost,

Fault code PO123 is now coming up but I am unsure if this is just an offshoot of something else.

I have already replaced the throttle pedal TPS assembly.

wont even get home tonight if it doesn't get sorted today.

Going to go and try the vac line to the actuator see if it can move at least....

[Hodge]

Hi All,

I pumped the bulb at idle, pulled the boost controller apart (all clean) and reset to 15psi, closed needle valve and went for a drive.

No throttle response at all , dead pedal , zero boost , reset needle valave and still no throttle response, dead pedal, zero boost,

Fault code PO123 is now coming up but I am unsure if this is just an offshoot of something else.

I have already replaced the throttle pedal TPS assembly.

wont even get home tonight if it doesn't get sorted today.

Going to go and try the vac line to the actuator see if it can move at least....

Hey mate. When my fuel relief valve on my CRD blew open, I was getting that code, 0123 and 1089 at the same time. I think i still got photos at home when I replaced mine. Geez been a while i dont remember the instructions for it. From memory it's check that there is NO fuel going through the valve at approx. idle pressures.

Not sure whether it's worth checking that out perhaps...

[Bidja]

P0123 Throttle/Pedal Position Sensor/Switch A Circuit High Input.

Suggest you clear all trouble codes and start from there as you have stated that: have already replaced the throttle pedal TPS assembly.

Yeah bypass manual boost control. There is a vac hose that runs along front of motor may have broken but you said that actuator is working with vac hose on/off actuator (check operation again).