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Discussion Starter #1
Hello fellow and former 2.8 enthusiasts,

I am having some trouble with what I think may be a fuelling issue with my Y60 2.8 (Mechanical Injector Pump).

Ill start from the beginning..

I bought the car roughly a year ago and she has been a great, reliable bus. It has been serviced every 5000kms and very well looked after (I have an inch thick stack of receipts). Because of all the issues about cracked heads I had read about, I replaced the entire cooling system upon buying it.

Shortly after I added a boost gauge, boost tee, pyrometer, temp guages, snorkel, zd30 airbox, K&N filter, 3" turbo back exhaust. I then started playing with fuel and boost and making some really great gains.

Looking at the service receipts I noticed she had never had a new set of injectors (315,000 on the clock). So i decided that before I really start going all out with tuning I should get new injectors. Got the injectors changed, and much to my surprise nothing really changed, no extra power and now it blows a little white smoke now and then. My thoughts are the old ones must have been fine.

Now that I had everything needed for proper tuning it was time to go get it properly dyno tuned, so I booked it in at United Fuel Injection. They were only able to squeeze a few KWs out of it. They said no matter how much they increase the fuel or adjust the boost compensator they couldnt really get any more power out of it.....and then they showed me this..



There is a worrying drop off in torque at around 2800rpm, it shouldnt be like this. It should keep going and going. After seeing this I fully noticed it in the driving. I knew it had a flat spot in that rev range before but now it was very apparent to me that something was wrong. I thought it might have just been my titting around with the boost compensator and fuel screw, but now I know there is an issue.

The tune itself was useless, they had put the boost up so high (14psi) that on full boost the car was getting no fuel, and i couldnt even get it over 100kms/h flooring it and temps were rising fast. The mix was so lean your could feel it. As soon as i got home i wound the boost back down to around 11psi, and I was back where I started, decent power and a good AFR mixture but really not what it should be.

After all this I have come to the conclusion that for some reason shes not getting enough fuel on full boost. Its like the main fuel, boost compensator etc have no effect on the fuel delivery after 2800rpm at full boost. If i turn main fuel up I can definitely feel the difference before the turbo kicks in, but not after.

Has anyone out there experienced a power drop like this before?
Did the new injectors have something to do with this?
Can anyone suggest possible reasons for any of this happening?
Where should I start looking? Timing? Pulling injectors again?

I should mention the injector pump was reconditioned in 2013 so its not leaking.

Thanks for reading all, any knowledge on this would be very well appreciated.

Regards,

Col

 

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Hey Col

I don't know whats happening there at the moment and won't say too much. But I have had 2 dealings with United and both have not gone well. I heard they were the best so maybe they have new employees.

I might add I have spent over $2200.00 with them so I am not just throwing rocks. I think there is an issue when you get the truck back worse than when it arrived.

But here is the thing when I did complain they did listen so maybe take it back and explain your situation. I think its only fair to let them address the issues you have AS they have been around for a long time so reputation is important to UFI.

We also use the same company for our requirements in the mining industry, and have had no real problems there. So like I said maybe there is staff changes or another explanation.

But let me say this, I fully understand the frustration mate.

It would be more useful if some of the members on this site who understand your variant of engine would comment, in regard to your torque curve.
 

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HMMM...this could be interesting.
Start looking for signs of hoses being sucked in (collapsed)...both intake and fuel. Check the tank vent breather inside the rear back guard for free air flow.
I run a 3'' dump on mine for a length of about 18 ''...and then its a 2 3/4 inch (63mm) all the way till tailpipe...where it goes back to 3'' because it exits out the side behind back wheel..pointing at ground on an angle so as to not cover my van in soot. The muffler is there for looks only. The reason for the smaller pipe dia for most of the length of zorst is coz my zorst builder says 3'' all the way kills the little diesels at higher revs..coz of "dead air" at all the bends..as the smaller engines don't have enough flow to keep it going along. Almost like a really restrictive muffler he reckons.
Anyway ..it works ok ...as my 2.8 will rev and pull really well to at least 4000..dunno wot its like past that as I never go there.

HTH.

Cheers Keith
 

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There is a very good thread on the injector pump in here. It deals with increasing the fuel and adjustments to the aneroid, thingy that increase the fuel as boost increases.

You may have a hole in /leak around the diaphragm that is in the aneroid.

Check out the thread it is great source.

This may also be the problem. When mine is really pushing on max boost the safety valve in the front of plenum chamber vents. That could be your problem, sound is very obvious of a gas escaping. Watch your boost gauge to see if it drops off when you get up to full noise, you may need to back off the boost just a little.
 

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Discussion Starter #5
Hey guys,

Thanks for your replies.

maysy1:

I would go back there but I got the feeling they are way too busy to give any 1 car real attention, especially an old one with a small engine that is hated by most. Not to mention the high prices (don't want to take it back and end up getting slogged for thousands with no results) I have given A1 Diesel Injection a call and spoken with John at length over the phone, he suggested checking the timing and is only charging $150 to have a look at my pump and adjust the timing, I will see how this goes.

Thanks for your input and comments. How is your truck going by the way? Last time we spoke you were having overheating issues if i remember correctly?

Keith:

All the intake hoses are good and I'm convinced there is no problem with air, it's gotta be fuel. As far as fuel hoses go, where should I be looking? I'm not familiar with the tank vent breather, how would this affect fuel flow and how do i go about checking it?

I have a Scott's Rods 3" Exhuast which I read reviews on prior to buying and all the guys with 2.8s that have them don't seem to have problems. I am familiar with the dead air theory but I don't think thats what is happening here, maybe I'm wrong.

The thing is that no matter how much I turn up the fuel I can't seem to ever create any black smoke, its just not getting enough fuel to smoke up.

Snail:

Are you referring to the diaphram thingythat the fuel pin moves up and down on? It's like no matter what I do with that thing there is no obvious change. I have turned it round a full 180 degrees with no real gains.

My boost holds steady when im flooring it, there is no PSI drop at all. Im pretty sure it should only vent if it spikes over 14PSI, mine never goes over 12. Correct me if im wrong.

The drop of power after 2800rpm is not sudden, its more of a gradual decline in power.

Below 2800 rpm i get that grunty fuel burning vibration feeling, and it pulls like a train, and after 2800 the grunty feeling goes away. Its like you can feel the mixture has just leaned right out, plenty of air, but the pump won't give it the fuel it seems. Maybe lowering the boost more will help.


Also, my revs seem to fluctuate A LOT at idle, I have to constantly ride the throttle just to keep it at my desired RPM. I'm starting to think it may be a faulty injector spraying fuel intermittently, as I can't seem to remember any of this happening prior to them being installed.

This is so frustrating!
 

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Hmmmm...where to look for collapsing hoses....prolly anywhere really....try anywhere near were the hoses go onto fittings...anywhere that they may have been squashed after fitting or repairing anything ...and so on. From memory ..I don't think there is a filter/strainer in the tank with diesels, but maybe someone else on here will clarify that.
The vent for the tank is inside a plastic guard that is in the RHS rear wheel arch .
It has a foam filter which clogs up /carks it after a while. I changed mine out to a boomspray nozzle filter ...fitted pointing down. There is also a filter inside the return Banjo on the back of the injector pump on these donks....but I would think if its blocked up you would get heaps of black smoke...which seems your not...but again...I stand to maybe be corrected on this hey. There is some threads on this filter on here...can be a PITA to clean (from experience).
Your problem is ..IMHO.. a rare one as usually it is the other way ..ie...too much fuel/smoke.

Cheers Keith
 

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Thanks for your replies.



Snail:

Are you referring to the diaphram thingy that the fuel pin moves up and down on? It's like no matter what I do with that thing there is no obvious change. I have turned it round a full 180 degrees with no real gains.

My boost holds steady when im flooring it, there is no PSI drop at all. Im pretty sure it should only vent if it spikes over 14PSI, mine never goes over 12. Correct me if im wrong.

The drop of power after 2800rpm is not sudden, its more of a gradual decline in power.

Below 2800 rpm i get that grunty fuel burning vibration feeling, and it pulls like a train, and after 2800 the grunty feeling goes away. Its like you can feel the mixture has just leaned right out, plenty of air, but the pump won't give it the fuel it seems. Maybe lowering the boost more will help.


Also, my revs seem to fluctuate A LOT at idle, I have to constantly ride the throttle just to keep it at my desired RPM. I'm starting to think it may be a faulty injector spraying fuel intermittently, as I can't seem to remember any of this happening prior to them being installed.

This is so frustrating!
Yes,

If adjusting this makes no difference, that is likely to be where to look. This device is supposed to increase the fuel as the boost increases. The spring tension is adjustable, did you find the tread in here? I have not had to fix mine so I cannot help further. Good luck

Re the rough idle, try bleeding the injector lines, sometimes air can be in the line and this will cause problems. Crack the line at the injector and turn it over to pump fuel.Cover the loosened connection with a rag or fuel will piss out everywhere.
 

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Is it intercooled?
What is stock boost?
Where were the injectors from?

Just cause something is new or reconditioned doesn't mean it is without faults....

The curve looks kinda similar in shape to my GQ TD42 with a/m turbo and stock fuel pump, basically I can't get enough fuel on a stock 10mm pump.
An air restriction or collapsing intake hose could become problematic at higher RPM too. Just a rough diagnostic only but remove the air filters and do a hot lap to see if the flat spot and higher RPM is still an issue.

What are your EGTs doing?

UFI have a good reputation for a reason, I would be at least talking to them again and explain what's going on and what your expectations are. Taking it elsewhere could create other issues, not that they are not good but picking up someone else's work is not always easy. Did you explain to UFI that you had adjusted the settings yourself prior to taking it to them? It may change what they do for diagnostics.

I'm not a guru but it does kinda sound like fuel, is the filter good? Having the tank breather blocked can create a suction in the tanks and restrict fuel flow so maybe try going for a hot lap with the cap loose?

Just a couple of things to think about
 

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Hey Col

my over heating issue was fixed by reconditioning my long motor:headwall:. I have since fitted a recon fuel pump and turbo. I have had issues with the turbo as per my pm to you. My beast also has an intercooler fitted.

By the sounds of things your pump may be due for a recon though the mechy you have now should be able to confirm. I would wait and see what they come up with. My recon pump was $1500.00. The pump was long due for mine and the turbo was done as a precation due to all the work I had done to the engine.


Paul
 

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Hi Col


any updates with whats going on with your Patrol mate?



Paul
 

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Discussion Starter #11
Right,

They reckon its definitely the pump causing the issues. Funny thing is I have a receipt from the previous owner of the pump being rebuilt 2 years ago. $1200 receipt. I guess they ripped the previous owner off, coz the pump is phucked! I did some more tweaking with it. I have now screwed in as much fuel as i can with no more idle adjustment available. It should be smoking like a chimney, but no, little puff at takeoff and no smoke on boost AT ALL.

Looks like I'll just have to bite the bullet and do the pump...when i can afford it.
 

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Hey Col

there is light at the end of the tunnel if you do get a recon pump. I must admit even though I have had some drama with my engine rebuild the thing goes like stink. It actually brought a smile to my face. I think you either love or loath the 2.8s in my case I like something different I don't like what everyone else does. Sometimes this impacts on my sanity but when the little 2.8 sings its note through the 3 inch system and that cool intercooled air rushes through the engine I know why I love the the little 2.8. Let us know how you go with the recon pump?

Paul
 

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Discussion Starter #13
Is it intercooled?
Just cause something is new or reconditioned doesn't mean it is without faults....
This is very true, it was done by the previous owner. All I have is a receipt, so I have no way of knowing exactly what was done to it. It simply says "remove and refit pump $1200"

Is it intercooled?
No, but i plan on doing so once these issues are sorted.

What is stock boost?
I believe around 10PSI, if i turn the boost tee down it doesnt seem to go below 10-11. Theres not even enough "on boost" fuel delivery for 10PSI, even with a few turns of the fuel screw and 180 degree turn on the diaphram.

Where were the injectors from?
Total Fuel Injection Balcatta. Cost me $500 to replace 6 incl. labour

The curve looks kinda similar in shape to my GQ TD42 with a/m turbo and stock fuel pump, basically I can't get enough fuel on a stock 10mm pump.
An air restriction or collapsing intake hose could become problematic at higher RPM too. Just a rough diagnostic only but remove the air filters and do a hot lap to see if the flat spot and higher RPM is still an issue.
You'd have to make the following assumption with any setup:
Air restriction = not enough air = too much fuel = heavy smoke....correct? If im right it cant be that.

Also, my turbo is not AM, its stock, therefore it should get a good curve if everything is working correctly. P.S have you tried reducing your boost pressure a bit? That might help with your curve.

Took your advice and did a lap without the filter, the turbo definitely spools quicker/less lag, and maybe 5% more power (however it was a very cold morning). Still not what it should be...

What are your EGTs doing?
EGTS are being really gay. Before the new injectors the truck happily cruised at 300deg at 100kms, now its cruising at 380-400deg. This is on a flat.

Up hill is horrible, if i put my foot down up hill at high speeds (long country road steady hill climb) the truck just doesn't go anywhere. The boost pressure maxes out but at those speeds because im doing over 2800rpm, the flat spot kicks in and the car just cannot increase speed. EGTS could easily climb to 650 if I pushed it. I havn't let it go over 550 though for obvious reasons.

At low speeds EGTs are great. Cruising at 70kms an hour in 4th i get around 220 deg. Still have plenty of power at that speed too, because my revs are not as high.

Can you see what all this is pointing to?

UFI have a good reputation for a reason, I would be at least talking to them again and explain what's going on and what your expectations are. Taking it elsewhere could create other issues, not that they are not good but picking up someone else's work is not always easy. Did you explain to UFI that you had adjusted the settings yourself prior to taking it to them? It may change what they do for diagnostics.
I might go and talk to them again. It was not my intention on this thread to make them look bad at all. UFI were originally going to charge me $300 for the tune but because they couldnt get any more power they only charged me $150. That was fair to say the least. I was just a bit annoyed that on the drive home I couldn't hit 100km/h on the freeway.

I was simply stating what happened in my experience with them. UFI are definitely up there with the best. I just wish rather than doing a full rebuild they could just diagnose the problem, which may not even require a full rebuild.

I'm not a guru but it does kinda sound like fuel, is the filter good? Having the tank breather blocked can create a suction in the tanks and restrict fuel flow so maybe try going for a hot lap with the cap loose?
Mate, you don't have to be a guru to help people out, sometimes the smallest piece of advice can help out even the most knowledgable. Your advice is really appreciated.

Brand new fuel filter, thought of that first.

I took your advice and went for a lap with the fuel cap off(and the air filter out). It seemed to make a slight difference but still not what it should be (again was a 3 degree morning so that could have contributed to the extra horsies). Still had the flat spot, high EGTS and no acceleration up hill. It's possible the tank breather may be a little blocked, but phark have you tried undoing those hoses? they are seized on good for me, i was too lazy to screw around with that at the time, especially considering it didn't make a great difference.

Col
 

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Discussion Starter #14
Hey Col

there is light at the end of the tunnel if you do get a recon pump. I must admit even though I have had some drama with my engine rebuild the thing goes like stink. It actually brought a smile to my face. I think you either love or loath the 2.8s in my case I like something different I don't like what everyone else does. Sometimes this impacts on my sanity but when the little 2.8 sings its note through the 3 inch system and that cool intercooled air rushes through the engine I know why I love the the little 2.8. Let us know how you go with the recon pump?

Paul
Haha. Words of inspiration Paul! I will not give up...Yes and you'd want it to go like stink considering you probably could have bought another RD28 patrol for what you spent fixing it! But yours runs like new now so well worth it, its all about the end result. My missus sees a car as a car, and as long as it drives from A to B then she can't see why it needs fixing, she doesnt understand why I need to spent $1800 on the pump. And to be fair, if im just driving around town its never an issue, the highest speed ill go is 100.

It's only ever a problem in 2 situations:

A) Long hill climbs B) Gunning it along the beach (where its soft sand and you need to keep the revs/momentum up)

Itd actually be fine if I went 4 wheel driving on my own, but can you imagine my mates frustration when every hill on the highway my truck slows them down. They end up just leaving me behind and meeting me there. And when we get there, if its a hot day that temp guage and those EGTS start climbing due to this same problem.
 

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So just to document my findings in case anyone else is having samilar issues:

Ive done the following:

-Removed the shim from under the diaphram to let the fuel cone/pin go down further
No real change

-Checked the boost line to the compensator - all good.

-Wound the spring seat all the way down to allow the diaphram to be pushed down easier - no real difference

-Rotated the diaphram in every flippin direction, didnt really make any difference. So i had a look if i could see the slide marks - the governing pin is definitely sliding up and down on the tapered diaphram cone/pin. This tells me the boost pressure is getting to the pump.

-This next test was interesting in the findings. I completely unplugged the boost hose to the top of the pump meaning the compensator wouldn't be working. Much to my surprise it wasn't THAT much worse. Honestly it had maybe 5% less power. This tells me that the compensator is definitely not doing it's job.

-All in all, looks like its gonna be a rebuild. Although I'm considering just buying a 2nd hand pump off a rd28 wreck and taking my chances, surely its got to be better than mine haha.

-The diesel shop I took it to recently spun it to me like this "Because you have new injectors they run at much higher pressure than the old ones therefore the pump has been flogged out as a result. Really? Because everyone I know that has had new injectors installed has noticed an instant world of difference.

Should have bought a 4.2, but just like any 2.8 bloke, its hard for us to let go. :)

Col
 

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Had the same problem with mine, started to misfire and loose all power after 2600-2800rpm..

For me i had to adjust the Timing.. Try to set the cold start timing device always on. This was enough for me.
 

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Hey Guys,

I'm glad to say this has been completely resolved. It was the injector pump, needed a full rebuild. It goes like THE CLAPPERS now. Just keeps pulling and pulling well above 3000rpm.

I would highly reccommend speaking to John at A1 Diesel Injection in Redcliffe on Great Eastern Hwy. The boys there did an awesome job on the rebuild.

I'm now very happy with the performace of my truck. When I can afford it i'll put it on the dyno and get a readout for everyone.

Col
 
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