patrol zd30 fuel pump issue?

[MadDan]

guys, as the title suggests, i'm havng some drama's with my injector pump

i've just replaced my motor after it did no2 piston, all is back in the car with the exception of an intercooler that i'm waiting for (delay on cross country intercooler order) but have got the motor running without it just to ensure all is ok internally with motor

i've done the usual things regards priming fuel, and motor runs fine when i'm priming it manually but it wont stay running when the pump has to draw it's own fuel??

seems to be plenty of fuel coming out of the line from filter to injector pump and heaps of pressure when i manually prime it so i'm leaning away from supply issues (mabye?... dunno)

doing my head in... the motor runs sweet when i give the primer a hit every 5 seconds or so... but stalls if i dont

is there something in the injector pump that would be preventing it from drawing it's own fuel, but still allowing it to perform as it should otherwise??

any ideas?

[NissanGQ4.2]

Although it's not compulsory MadDan, you might get more assistance from members if you head over to the introduction section located HERE (http://www.nissanpatrol.com.au/forums/forumdisplay.php?2-Introductions) and tell us a little about yourself and your rig, we are a friendly community and like welcome in our new members :)

Cheers

Todd

[MadDan]

i'd rather not say much about my rig right now... after holing no.2 piston... now this... i'm a little annoyed with it... lol (stock 2005 zd30 motor wise up till now so not much really to write up about)

i'll get around to a write up later today if once i get back home ;-)

[Yendor]

A lot of people fit electric lift pump down near the fuel tank. This might help with your problem.

It's not a problem with the fuel tank breather is it? try running the vehicle with the fuel cap removed.

[MadDan]

it wont run with cap off, however does run when tank is pressurised

am toying with the idea of running a lift pump, however it's been mentioned that it may be the front seal of the injector pump drawing air (easier than drawing fuel from the tank)

little concerned that if i do happen to have a stuffed seal, what happens if i pressurize the pump??... will i then start pumping fuel past that seal and into the timing chain area?...

NOT looking forward to pulling the injector pump back out!!.. only just had the bastard of a thing in my hands a few days back when i swapped it from my old motor to the new reco'd one (was told pump wont need anything done as it was running fine before)

thanks for the reply Vendor.. any idea is helpfull at this stage.. really hoping it may be something simple i'm overlooking... but i'm stumped... only thing that seems to fit the problem is that front seal, but i'd like to get some more info on that before i go pulling the pump off to fix it

[Yendor]

I don't know anything about IP, all I know is that mine is a pig of a thing to bleed the fuel system every time I replace the filter and until I get every last bit of air out of the system she runs like a pig.

I would of thought if your IP was sucking in air then it would also be running very rough if it ran at all.

Is there some sort of filter in the supply line at the IP?

Your best bet might be to have a chat with the company you are going to get to overhaul your IP and see what they think before you remove it.

Good luck with it.

Cheers Rodney

[MadDan]

i wasnt planning on overhauling it, cause it runs perfect while i'm keeping fuel up to it, i'll just pop a new front seal in it (hopefully) if that is in fact the problem

your thoughts are similar to mine, if it was sucking in air i wouldnt of thought the motor would recover from nearly stalling to idling fine with a simple few pumps of the primer!

in the past i've run out of fuel (long range tank with big flat area on the bottom is prone to letting the intake sit above fuel level on angles) i've just popped the injector pump supply line off (between filter and pump) sucked fuel back up to the filter (not the best method... but hey.. it works) then re-attached and primed it while turning the motor over and it eventually fires and runs.. haven't had to touch the injectors or anything

i'm gonna swap a new filter onto it as it may of somehow become more restricted than it was prior, and fit a clear line to the fuel return off the pump to see if i do have any air coming back out of the pump and take it from there

[Brisat]

It will most likely be an air leak at the filter, mine was a real bugger of a thing to get it to seal properly

[MadDan]

i really hope it is... but there's certainly no leaks when i pressurize the line. that doesnt mean that i dont have a leak when the line is under vacuum though

will replace with clear line through the week and also replace the filter while i'm at it

i'm also going to move the spill line from the intake on the pump to the tank return line (got me stuffed why it's on the intake line anyways?)

if i still have no luck then i'll have to bite the bullet and pull the pump out i think and replace that front seal... just would like more info on that as it's not covered in the manual that i've got (sounds like a simple job.... but would like documentation just in case)

[MadDan]

problem sorted!!!!

started running through things today... put the clear hose on... plenty of fuel flow and no air... pumped any air through real quick... so nothing that side.... which made me think that... yup... gonna have to pull the pump :-(

thought id just pull the spill line off the pump and pop it into a bottle to see what was coming out that end... and just blocked that pipe into the injector pump with my finger.... and walla.... it ran sweet!!

soo... either my spill line hose is leaking (doubt it as it's in good nic and fits nice n tight) or i have a banjo washer on top of an injector not sealing... so new banjo washers on order just to be sure... and i'll plumb the spill line back to the return as i see no need for it to go back into the intake line of the pump

thank F*CK for that!!