zd30 stalling randomly

[Jakeex]

hey guys,
been having a bit of a tricky problem for a few weeks now and can’t find any answers

back story.
so the nav, zd30, used to be my daily but now i have my own business and drive a van for most of my travels. nav sits in the garage on charge and i drive it every few weekends.
been extremely reliable.

drove to my sisters a few weeks ago, (25mins) got there fine, sat for around an hour and when i got back in, it cranked but wouldn’t start. primed it, checked all the fuses but no luck. then 5mins later it just started. took off and it stalled out the driveway. same thing, cranked for a while and then after a minute or two it started.

drove to my in laws place with no issue (20mins) then parked for about an hour again, and wouldn’t start. this time no luck, waited 20mins or so and tried again but just cranked over.
luckily my house is a 10min walk so i went home and a few hours later went back, it started as normal, drove home no worries.

did the obd diagnostic with pins 1 and 8 and found 0407 iirc, crank angle sensor. cleared the code, ordered a new one and while i had time, changed the fuel filter since it was due.

got the new sensor, installed it, went for a drive, maybe 10 mins in, it stalled. jumped out, primed it and it started. then stalled again 10mins later.
did a big block a few times and it was just random, sometimes i’d get home with no problems, sometimes it would stall, sometimes just stutter and keep running. but then the last 2 blocks i drove, i had no problems, so i thought maybe i didn’t prime it enough when i changed the filter and it was just a coincidence. checked again and no codes.

it sat for another week or so, i checked the battery, it was a little low so i thought maybe low voltage was the issue. but then disconnected the alternator, had it idling at 12v and then turned on everything i could and got it down to 11.1v with not even a hiccup.
charged it anyway.

drove back to my sisters place with no problem, sat for a couple hours. on the way home it stalled but it fired straight back up (with the key) while still rolling. did it again in 50m, started it and drove the next 15mins home without a problem.

googled for hours and a few people suggested clear hoses at the primer to check for air (it does sound like air in the fuel to me)
i have the inlet side with only very very small bubbles, basically solid fuel delivery. and the outlet side of the primer is foamy like a kitchen tap, big bubbles randomly etc.

thought that was 100% my issue, so ordered a new primer (non genuine unfortunately) installed it, made sure the filter was all on correctly, but with clear hoses it’s exactly the same.
both primers prime hard though, and with it idling and holding revs at about 2k, even with the bubbling outlet line, it sounds perfectly fine, no stutters, stalling etc.

i haven’t had time to drive it yet with the new primer, but chasing any other ideas on what this could be. really hoping it’s not the injector pump, but with the list of codes i figured if it was, something would show up.

sorry for the long read, but i figured more info is better

thanks for any help in advance!

 

[tweak'e]

a common place for air to be sucked in is the filters bottom o ring. people forget to change them, or install them twisted. check the hose ends, a few people have found them split at the end. also double check its the right filter, i had one wix filters list the wrong one before. same fittings but different filter.

any sign of diesel bug? i wonder if you have got something clogging the pipe down by the tank or even the tank pickup.

 

[Jakeex]

thanks for your reply

never even considered diesel bug, will have a bit of a read into that
thought about pulling and cleaning the tank just as something to do anyway so might have to now.

i’m sure the filter came with a new bottom o ring and i always coat it in diesel before fitting to lubricate it. wondering if the water sensor is letting air in too, but haven’t found much online saying anyone has had issues with them

fuel lines, i’ve replaced the outlet side with another piece of hose as a test, didn’t have enough on me to do both but with clear hoses the inlet side had very little air and the outlet side had a lot, so assuming it’s not a hose causing that

 

[Erick]

The best diagnostic tool for all the problems you have written about is an in-line low pressure pump. Depending where you instal it, you can find out delivery volume (blocked pickup/fuel line), instal before/after filter to create vacuum /positive pressure to check for air leaks, etc. You can run vehicle with pump going or not if fuel delivery system is good.

 

[Jakeex]

hey mate, that sounds very interesting, can you elaborate on this a little? is this something you’ve done?

i’m pretty mechanically minded, i understand how that would be an upgrade but can’t picture how this would work as a diagnostic tool though. like how do you work out what is happening with the pressure, by installing the pump?

is this in conjunction with the clear lines? moving the pump causes air bubbles in different spots, or eliminates air bubbles, etc?

thanks!

 

[Erick]

hey mate, that sounds very interesting, can you elaborate on this a little? is this something you’ve done?

i’m pretty mechanically minded, i understand how that would be an upgrade but can’t picture how this would work as a diagnostic tool though. like how do you work out what is happening with the pressure, by installing the pump?

is this in conjunction with the clear lines? moving the pump causes air bubbles in different spots, or eliminates air bubbles, etc?

thanks!

In reply. Yes I have inline pump permanently installed. Does not have to be operational, I have a seperate switch Since I sorted some problems a couple years ago I have not used it. I got rid of the primer bulb set up and use a generic filter/water seperator.
If and I say if your problem is air in fuel, the inline pump can be used as you suggest to see flow rate ( possible blocked line, etc) or air entering system. The zd30 is pretty basic compared to newer vehicles, the other things I can suggest is check earth points and wires at the three points along intake manifold in particular and the connector/wiring down to the injector pump. Although your experiment with running down the voltage seems to indicate all is well there.
The other thing to check is the duty cycle (IDC) of the pump. Need to go to a Bosch diesel place, but the check is just a plug into your diagnostic port in the cab. As the pump gets older it may be having trouble picking up fuel.
It is possible the injector bleed off line running from front top of cylinder head is leaking. For some reason they run it to the intake banjo on the injector pump. And there is a small filter there as well.

 

[tweak'e]

commonly its the primer, that leaks. or the filter orings. checking the water trap valve is a good idea.
i have a thread on here where i removed the primer, welded a plate on top and used an outboard motor type squeeze bulb back at the tank as the primer.

if you fit a fuel lift pump, if the leak is big enough it may leak and you can find it. a good thing to test, but what often happens is the leak seals itself.

having some fuel pressure on the injection pump is a good idea. there should be a few threads on it.
you would need something like a holley high flow pump, some one way valves as bypasses (in case the fuel pump is off). a way to power the pump and have it shut off in an accident. spill line mod (move the spill line from the ip inlet to the ip outlet).