GU Patrol 2.8 fuel issue
Submitted: Saturday, Nov 21, 2015 at 11:20
ThreadID:
130945
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7
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michael d3
Hi All,
I am having a fuel issue with our 2.8 GU and though perhaps you could assist with diagnosis.
I have just had the injectors removed and checked and found them to be operating perfectly. On reinstalling injectors the system was bled of air and the engine started up without fault and it continued idling for approx 5 mins then stopped.Symptom was as though it ran out of fuel ... started missing and engine gradually slowed to a stop after 5-6 seconds. Engine will now run but only after re bleeding air out of the systen and then it will run for approx 10 seconds and stop again. I Connected a bottle of diesel via a hose directly to the fuel pump inlet line thereby removing all connections/lines/filter etc between the tank and the fuel pump but the problem still exists. There is no guaze filter in the fuel pump intake.
Prior to removing the injectors the car was running fine and this was more of a maintenance
check rather than due a pre existing fault. From here I have no idea where to go or what to do and any help/ advice would be greatly appreciated?
Thanks
Michael
Reply By: Member - Warren H - Saturday, Nov 21, 2015 at 11:45
Saturday, Nov 21, 2015 at 11:45
Know nothing about diesels, but you could see if you can find some info on the patrol 4x4
forum, here's one poster with an
issue after an injector service.
AnswerID:
592966
Follow Up By: michael d3 - Saturday, Nov 21, 2015 at 12:31
Saturday, Nov 21, 2015 at 12:31
Thanks Warren,
On the back of your reply, I have popped a post over at the 4x4
forum , I'll see how I go.
Regards
Michael
FollowupID:
861155
Reply By: Been-Everywhereman - Saturday, Nov 21, 2015 at 11:53
Saturday, Nov 21, 2015 at 11:53
Sounds like a classic case of sucking air from somewhere. Something must have been upset during the process of injectors. If you have a (cat style) glass fuel filter I would be checking for slight cracks in that area or some joins leading to filters or hoses you may have played with. Quite often you won't see a leak because it is to busy sucking air. Only has to be slight. Just my 1 cent worth. Been caught by that before.
AnswerID:
592968
Follow Up By: michael d3 - Saturday, Nov 21, 2015 at 12:29
Saturday, Nov 21, 2015 at 12:29
Thanks Been-Everywhereman,
Yes those were my thoughts as
well and I have no doubt there is air entering the fuel pump either by a leak or by cavitation. But after bypassing the entire fuel intake (filters lines etc) and plumbing direct fravity feed to the fuel intake I think I have eliminated the leak theory. Typically a leak downline (injector side) of the pump will not introduce air into the system,excepting in some circumstances where the leak off lines plumb back into the intake line. Ours run back to the tank however so I don't think it likely to be a source of air intake.
Which perhaps leaves the pump .... coincidental it should develop an issue 5 mins after injector installation, I'm not so sure
FollowupID:
861154
Reply By: Roachie Silverado - Saturday, Nov 21, 2015 at 12:44
Saturday, Nov 21, 2015 at 12:44
Not sure I can assist, because of your "test" which sort of proves it may not be air getting into the system prior to the IP. So, it does sound like the IP might be the problem.
However, I have a basic theory about diesel engines and it goes along the lines of: Don't rely on the IP to draw fuel from the tank to quench it's thirst!!!
As such, I like to install a lift pump near the tank, which supplies a POSITIVE fuel feed to the IP via the filter.
In the case of my current truck (a 2012 Chev Silverado 6.6 Duramax), I have installed one of these:
http://www.fassride.com/shop/fuel-air-separation-systems/fass-titanium-series.php which provides more than enough fuel for the engine AND the fuel is pre-filtered AND (most importantly) it supplies AIR-FREE fuel to the injectors:
https://www.youtube.com/watch?v=x4LCbGsujdU
You wouldn't need the 150 for a Japanese vehicle, the FASS 95 would do the trick.
Sorry, it may not solve your current problem (but it MAY...???? who knows). Might be worth fitting one anyway and if it saves you from having to get your IP re-built then it would actually save you money!!!
Good luck,
Roachie
AnswerID:
592971
Follow Up By: Member - John - Saturday, Nov 21, 2015 at 13:41
Saturday, Nov 21, 2015 at 13:41
Roachie, hi, just a quick question if I may? Any reason you chose the FASS over other brands? I have specified the AirDog system for my Duramax in the Patrol, not sourced yet, am interested in your thoughts on the FASS. Thanks in advance.
FollowupID:
861156
Follow Up By: Roachie Silverado - Saturday, Nov 21, 2015 at 17:26
Saturday, Nov 21, 2015 at 17:26
John,
I think it might be a bit of a "Ford V Holden" thing to be honest.
I didn't know much about either brand....just what I'd been reading on various US forums.
It seemed to me that there were more "yays" for the FASS than there were for the Airdog....but I have no personal reason to believe that one is better than the other.
I can only imagine how pleased you will be with the torque you have available when you get the Duramax fitted to the Patrol. They are a great donk for sure. The only reason I didn't go down the same path is weight. I think there is already too little payload available on Japanese (and other brands) 4x4s, so adding the extra weight of the 6.6 would (I assume) detract from the amount of gear you can have on the Patrol. (??) I would happily stand corrected.
Cheers and good luck with the conversion.
Roachie
FollowupID:
861158
Follow Up By: Member - John - Sunday, Nov 22, 2015 at 02:14
Sunday, Nov 22, 2015 at 02:14
Roachie, not all that much difference in weight, but just to be sure have had a GVM increase done as
well as a double cab ute cut with alloy tray. Got rid of the dual wheel carrier, 80kg, drawers another 70kg and a lot of sheet metal. Should be
well under GVM when fully kitted for extended touring. Engine and gear box being rebuilt, ready in Feb, 650HP all up. With the old tunes 430HP but buggered injectors etc, got 9.85lt/100kms, sitting on 110, the ADC blokes reckon towing Aussie Swag should see 10lt/100kms, not towing 6-7lt/100kms. Fingers crossed.
FollowupID:
861168
Reply By: Member - Peter G20 - Sunday, Nov 22, 2015 at 11:09
Sunday, Nov 22, 2015 at 11:09
Hi there
I own a 2.8 model too! Bought it new in 1998 and its covered near 400K without any issues!!
I'm thinking your fuel filter may not be primed properly!
When I service my patrol I find it hard to prime the new fuel filter using the manual
hand pump.
I find that you need to keep the exit line disconnected while hand pumping until you see the fuel squirting out!!
Once you have achieved this reconnect the line and the engine will bleed itself and settle quickly.
I hope this may be of some help.
Cheers
Pete
Pete
AnswerID:
592994
Follow Up By: michael d3 - Sunday, Nov 22, 2015 at 18:09
Sunday, Nov 22, 2015 at 18:09
Hi Peter,
Thanks for your
feedback.
I believe by connecting a fuel supply direct to the Injector Pump, thereby bypassing the fuel filter/primer and supply lines, I have eliminated any priming issues normally encountered .
The symptom still exists after removing these items from the equation.
I can get the engine to run , and, providing I leave one injector line cracked the engine will continue to run. This would under normal circumstances bleed any air out of the system if it were not primed correctly. On tightening the injector line however the engine then slowly shuts
down as outlined in the opening post.
I will keep looking
Thanks
Michael
FollowupID:
861192
Reply By: pop2jocem - Monday, Nov 23, 2015 at 10:45
Monday, Nov 23, 2015 at 10:45
Michael,
I'm not familiar with the 2.8 Nissan fuel pump so the following may or may not help much.
Is it a rotary or inline type IP? Most rotary pumps have their own internal lift pump. Most inline pumps have a lift pump mounted on the side. If you have connected the independant fuel supply to the inlet side of the inline style lift pump and it is still running out of fuel I would suspect that the lift pump is faulty (coincidence?) or some foriegn body is caught under either the inlet or delivery valve.
Inline IP will not lift fuel without the externally mounted supply pump.
Just a thought
Cheers
Pop
AnswerID:
593027
Follow Up By: michael d3 - Monday, Nov 23, 2015 at 20:39
Monday, Nov 23, 2015 at 20:39
Hi Pop,
It runs the rotary type, and as such has no external lift pump.
Thanks
FollowupID:
861228
Reply By: Rob K (VIC) - Monday, Nov 23, 2015 at 14:29
Monday, Nov 23, 2015 at 14:29
Hi Michael, I'd be going back to what you "checked" - the injectors.
I'm not familiar with the 2.8 litre Patrol but have assume they might be mechanical injectors which have pre-set break pressures to manage the fuel load going into the engine. If so, when you had them "checked" what work was done on them and is it possible the settings have been upset with either refitting them or having them "checked"? Alternatively, has the IP lost it's ability to achieve the break pressures when you undid the lines and took the pressure off the downstream side of the IP?
Just some thoughts if you believe there are no blocked filters of air leaks between the IP and fuel tank. I'm not a mechanic either but an interested observer with a Toyota 1HZ engine with mechanic pump and IP.
Best of luck.
Rob K
AnswerID:
593030
Follow Up By: michael d3 - Monday, Nov 23, 2015 at 20:45
Monday, Nov 23, 2015 at 20:45
Hi Rob,
Thanks for your
feedback.
Yes injectors have set break (injection) pressures and speaking with the pump
shop today the boys said no adjustments were made as the injectors were operating as per OEM spec.
There may be an issue with the IP but it just seems to coincidental that it would start playing up just after r&r the injectors.
My next step will be to install some clear tubing in the lines (supply and return) to see if I can identify the origin (if any) of air in the system. I am back at work for 9 days now but will post up developments for anyone interested when I return
home next week.
Cheers
Michael
FollowupID:
861229
Reply By: michael d3 - Wednesday, Dec 02, 2015 at 21:52
Wednesday, Dec 02, 2015 at 21:52
Hi All,
Been off to work,
home again and back to the fuel problem and thought I would give you an update
So during the removal process the injector leak off rail cracked at one of the joints which wasn't a big deal and we got the local engineering
shop to braze it up. Didn't realise it at the time but it seems when they did the job they blocked the line. Result : engine wont run. It was only when testing for leaks that we found the blockage. Purchased a new rail and presto, fired up straight away and all good
Thanks for your
feedback
AnswerID:
593338