Zd30 fuel primer function

[ShortyNavros]

Hi Guys,

So occasionally I have been getting the dreaded 0707 error code which often occurs with pump fair or air in fuel lines or dirty fuel. I believe its the original pump at 190k so who knows it could go at any second haha. The fuel is fine I have checked, there is new filter on there. So that leaves me with the fuel lines or the primer.

The primer is a POS as everyone knows. How can you tell if it is leaking under vacuum? The stupid thing drains back into the tank unless you clamp the inlet side, you would think a fuel primer would have an anti drain back valve in it, this is why the primer is so shite, it pumps the fuel fine but as there is no drain back valve is just moves the fuel back and forth getting it nowhere.

I found this out when I fitted some clear hose after the primer and tried to prime the filter and got not fuel. Sucked it through with my mouth and it works fine. Now there is fuel in the clear line try using the primer and it just pushes the bit of fuel in the clear line back and forth (with it looped up), is this the normal function of the primer or is it actually defective?

My 0707 code has just popped up randomly like yesterday it did it idling into my garage not even in gear, no evidence of engine splutter at all. Previously it happened about 2 months ago when trying to start the car and it wouldnt fire after about 10 cranks, stopped and re cranked it and started fine but then had the engine light on with the 0707 code.

I'm thinking about just replacing all the stock fuel hose from the tank to the pump. The piece from the primer to the pump is new and the piece from the fuel tank to the hard lines is new cos I put a long range tank in and had to put in new hose to fit, the long range tank install is irrelevant cos I have had the 0707 error before the install and after. The hard lines appear fine, ie. No rust or cracks visible. Also the sender looked fine when I swapped in from the old tank into the new long ranger? Not that inspected the pipes meticulously as this before I started investigating it.

Any thoughts?

Cheers
Shorty

 

[tweak'e]

sounds like the one way valve in the primer is not working.

easy fix here is to fit a one way valve down by the tank.
a great fix is to fit a lift pump. that will pressurizes the lines and keep air out. easy to spot fuel leaks, difficult to spot vacuum leaks.

 

[ShortyNavros]

Tweake I knew you would come to my rescue, I used the clear vinyl trick and can't see any air bubbles, I got a tiny bit of air when I reved the engine right up to 4k but not enough to even make the engine splutter. Right so the primer should have a one way valve in it then? You can still use the primer as I think the priming motion pulls in slightly more than it let's back but it's not exactly efficient, using the suck through method is way easier then priming for the last bit. I'll replace the only piece of remaining oem fuel hose there is as a preemptive measure and also replace the shitty Nissan clamps, as even when in place you can twist the fuel line easily the clamp just stops you being able to just pull the hose off the barb.

A one way valve by tank is a bloody excellent idea. Also I have already done the spill line return mod. The return line isn't as important as air leaks here aren't going to matter so I don't need to go insane fixing all that up unless it actually springs a leak and I start losing fuel yeah.

The lift pump is a great idea and I have read about it but I have spent an absolute fortune on this car already and can't justify the extra money and extra time trying to fit it, like where would I even mount the bloody thing? There is no room near the tank, I have seen it done on tray back utes because of the surplus of room under the tray. Not as easy for me with a tub

 

[Horatius]

Hi Guys,


The primer is a POS as everyone knows. How can you tell if it is leaking under vacuum? The stupid thing drains back into the tank unless you clamp the inlet side, you would think a fuel primer would have an anti drain back valve in it, this is why the primer is so shite, it pumps the fuel fine but as there is no drain back valve is just moves the fuel back and forth getting it nowhere.

I don't know how to check it for a leak under vacuum. Mine isn't that old, but if I change a filter and don't bother clamping it the fuel in the line obviously runs back to the tank, but then it pumps the fuel up and fills the filter very quickly and without running back to the tank while doing this.

Can see how a faulty one way valve would cause starting issues, not sure how it's going to give that error message while it's running? I could be wrong though.

I found this out when I fitted some clear hose after the primer and tried to prime the filter and got not fuel. Sucked it through with my mouth and it works fine. Now there is fuel in the clear line try using the primer and it just pushes the bit of fuel in the clear line back and forth (with it looped up), is this the normal function of the primer or is it actually defective?

You're probably not going to pump much fuel with all the hoses on, should be enough to prime the pump though. Sounds like it's stuffed IMO. How my times can you work the plunger before it goes solid? Should only be about three times.

I changed mine because it wouldn't work properly and because I thought it had a leak (it probably did have a bit of a leak, the error message ended up being from a gut full of dirty fuel though).

My 0707 code has just popped up randomly like yesterday it did it idling into my garage not even in gear, no evidence of engine splutter at all. Previously it happened about 2 months ago when trying to start the car and it wouldnt fire after about 10 cranks, stopped and re cranked it and started fine but then had the engine light on with the 0707 code.


Any thoughts?

Cheers
Shorty

If the fuel is good, then it's more likely not holding pressure because of a leak somewhere. Worth checking all of that stuff before going to the pump, obviously. Big bickies there.

 

[Horatius]

Hi Guys,

The fuel is fine I have checked, there is new filter on there. So that leaves me with the fuel lines or the primer.

ps. How did you check the fuel? Last batch of crap fuel I got gave no real indication at the filter itself. In the tank itself was a different thing though.

 

[ShortyNavros]

I literally just installed the long range tank probably 2 tanks ago. There was still some rust and debris in there so I ran the tank right down from the top and drained the last 10L. Obviously the fuel cycles continuously so the filter had a whole bunch of rust and liquid crap in there. The 10L I drained from the tank was clean as a whistle. Obviously the long range tank let's me drain via the bung. With a fuel primer you wouldn't expect the fuel from the filter to drain back to the tank, its counterintuitive, like even the simple fuel bulb primers in boat fuel systems have a valve in them to stop draining backwards. No idea how to tell if the primer is actually cactus. I could just get a bulb style primer and fit it inline before the filter? No idea if anyone has done that?

 

[ShortyNavros]

https://www.ebay.com.au/itm/Fuel-Fi...036443?hash=item34065cad9b:g:mKoAAOSwAzVch2QM

Shit this would be the go, it's a td42 primer which looks identical except it has a bleed screw! Not that this would help bleeding after the filter but the assembly still takes a z332 by the looks of it and it's cheaper than the zd30 primer filter assembly which usually sells for close to 200 bucks. Would mean if you could remove the filter without disconnecting any lines you could pull fuel into the new filter and bleed the air from the filter. I pretty much always have to remove the assembly to change the filter cos mine is located in a very tight location near the brake lines just behind the battery.

 

[ShortyNavros]

Also I have never actually checked the rubber seal on the inside of the primer which seals around the central threaded portion. Are they something you can replace?

 

[tweak'e]

Also I have never actually checked the rubber seal on the inside of the primer which seals around the central threaded portion. Are they something you can replace?

they typically do not have that rubber seal as most filter seal on the threads.
those that require them the filters usually come with that seal.
old designs may have loose machining tolerances so the filters don't seal on the thread hence the need for the seal.

also it won't fix the primer problem an it won't stop air being sucked in.
that inner seal only stops fuel from bypassing the filter.

 

[tweak'e]

I could just get a bulb style primer and fit it inline before the filter? No idea if anyone has done that?

yes thats been done. if i remember right they have a built in check valve.
i would install it by the tank.

 

[Horatius]

I literally just installed the long range tank probably 2 tanks ago. There was still some rust and debris in there so I ran the tank right down from the top and drained the last 10L.

You might have some crap in the fuel lines? I had to take my tank out and lift the sender unit, to drain it, but it wasn't enough. Took it out again and found that draining it still left a thin layer of grime/dirt around the tank that wasn't easy to see, until wiped it with a rag. So had to give it a thorough clean. Got to say that it wasn't easy to clean properly. Had to blow out the fuel lines as well. That got rid of the alarm/code/engine light. All from topping it up with about 1/4 tank of crap fuel.

With a fuel primer you wouldn't expect the fuel from the filter to drain back to the tank, its counterintuitive, like even the simple fuel bulb primers in boat fuel systems have a valve in them to stop draining backwards. No idea how to tell if the primer is actually cactus. I could just get a bulb style primer and fit it inline before the filter? No idea if anyone has done that?

You sure wouldn't expect that, there is obviously something weird going on there. Then again, your not the first person to have all sorts of issues after fitting a long range tank. Have heard of it before.

ps. With all hoses connected and engine off after it has been running, how many times can you work the plunger before it goes solid? Should be no more than about 2-3 times.

 

[ShortyNavros]

Yeah I get about 3 plunges max. Tweake is there a reason I should put the primer bulb by the tank? I got one from a boat builder joint. I was gunna just stick it inline on the piece of hose which goes from the hard line to the fuel filter as there is a space there plus I could use it to prime a new filter is the filter/primer ever actually shits itself and stops priming all together. Also apparently they work most effectively vertical so they you aren't solely relying on the spring valve as gravity works to close the one way valve as well as the spring?

 

[ShortyNavros]

I should also mention my fuel filter location is on the other side of the engine bay to stock so I no longer use the hard pipes which travel along the firewall. The filter is connected directly to the hard pipes on the chassis rail near the drivers feet

 

[tweak'e]

Tweake is there a reason I should put the primer bulb by the tank?

yes.
its very hard to suck fuel (and air) uphill. the fuel come down out of the tank fills the primer rather easily. also down at the bottom is an ideal place for a one way valve. this way you can disconnect the hoses at the filter and not have fuel run back to the tank.
downside its a bit of a pain for priming the pump as you can't see fuel coming out of the filter.

 

[ShortyNavros]

Okay sweet well ill put the primer in down just next to the tank before the start of the hard lines. Had the error code come up again today just idling up to a roundabout no engine issues at all, drove for about 10mins after to my destination and pulled the code sure enough the 0707 code was there again. When I fit the primer bulb I will purge the lines with an air compressor and pull the fuel filter out and check the inside of it through the bottom. When I ran the first tank of fuel through after the long range tank install it had a fair bit of gunk in there which was left over from me first flushing the tank with water then letting evaporust sit in the bottom of the tank as this was where most of the rust particles were. After all this I put 3x5L lots of diesel into the tank, tumbling it over and over and then draining before I fitted the tank.

 

[ShortyNavros]

I do have ecu talk. Is there something I can look at gauge wise to see if the fuel pump is on the way out? Like the icv%

 

[ShortyNavros]

Did some reading on the patrol forum. And saw ranges of 40-70 icv% was normal, local diesel specialist said lower end for d22s was 35% at hot idle. Mine at hot idle is 7 or 8% which ain't good and my cruising numbers at between 10 and 15% at say 2k revs cruising at 80 or 100kph. I will eliminate the fuel system by running the fuel line inlet and return directly in a clean container of diesel and see what the icv% is at hot idle then. I do suspect the pump however as I did the clear hose trick and saw no bubbles between the filter and the pump. It's just so strange that as it seems the pump is on the way out but there are no noticeable symptoms with the cars performance being pretty well normal?

 

[ShortyNavros]

Ran the pump direct from a container of diesel to rule out an air leak in the lines. The icv% was identical. At warm idle after the drive home it was better at 14% but still way out of spec. Car still runs and drives fine and no error codes even though on the drive home I saw the % drop to 4 or 5 multiple times.

 

[Boogieboots]

Yeah I recall reading on Bailies Diesel that below 25 is considered a dead pump. 0707is the code to expect. That is an expensive fix, but cheaper than a new bus!

 

[tweak'e]

keep in mind what your reading the icv with. i think ecutalk reads it back to front, theres info in the patrol forum on that.