Troubleshooting loss of power at upper RPM

sk66 said:
FWIW, when I checked the banjo bolt on my IP it had the filter screen internal and non-removable... now I'm wondering if there isn't another one behind it like you found.
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The IN on mine had the spring and filter under the bolt. Which is where I found the clog.
The OUT had a filter built into the banjo bolt itself, it appeared to have 3 tiny flanges that hold the screen inside the cavity of the bolt. Could likely be removed if you bent the flanges that lock it in place.
I felt it was not worth the trouble since it appeared to be clean and brake cleaner passed through the bolt and shot out of the tiny passage on the side of the bolt shank with no trouble.
 
Just checked, that's why I didn't remember the screen like you found; my inlet side doesn't have it.
I think I'm going to add one of those in-line filters and leave the bolt unscreened (I can't find the parts in the diagrams anyway). Seems like a better solution than messing w/ crush washers and tiny parts that are easy to loose.
 
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I have noticed it takes more turns of the starter to get the engine going now...maybe I need to make sure I tightened the bolts down enough...or replace the crush washers...or re-anneal them at least.
 
sk66 said:
Did you bleed the line when you reconnected it?
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Yeeeaaahh, i should do that.
‍:cool:
In my excitement to see if the clog was the culprit I just started’er up and moved on. Probably a bubble that finds its way back to the line after it sits for a bit.
 
sk66 said:
Did you bleed the line when you reconnected it?
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Hah! Pretty much every time I pull a fuel hose off, reconnect it, and start the engine I think "I really should have bled that". About an hour later. ;-)

A small amount of air in the IP will stay near the top and make its way out the overflow port at the back, the fuel level shouldn't get low enough that air makes it to the high-pressure plunger (and from there to the injectors). No need to bleed the injectors for a mere fuel line change, but pumping the fuel filter pump a bit to cycle the air through wouldn't hurt.
 
Growlerbearnz said:
Hah! Pretty much every time I pull a fuel hose off, reconnect it, and start the engine I think "I really should have bled that". About an hour later. ;-)

A small amount of air in the IP will stay near the top and make its way out the overflow port at the back, the fuel level shouldn't get low enough that air makes it to the high-pressure plunger (and from there to the injectors). No need to bleed the injectors for a mere fuel line change, but pumping the fuel filter pump a bit to cycle the air through wouldn't hurt.
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I did bleed it, some air came out...not all that much but I’m still having the increased starter effort.
Turn the key, wait for my GP relay clicks, turn it over a couple seconds, kinda stumbles like it wanted to start but dies. Kill the power at the key, wait a couple seconds, repeat starting process, takes 2 or 3 tries doing this, then starts and runs normally.
Before fooling with the IP screen filters it started up right away...
 
Growlerbearnz said:
Ah, I embedded it too subtly in the text. https://www.amazon.com/Dorman-HELP-55241-Glass-Filter/dp/B000CO95SC
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Annnnd this is in my Amazon cart now. $10 is worth it to have not only a easily inspected area for debris in fuel, water or air ingress....but also has a much larger filtering surface area than the tiny filter in the pump, you could probably have 20X the debris I found in my pump filter and this larger one would still supply enough fuel to not give issues....I like it!
 
DelicaStuff said:
I did bleed it, some air came out...not all that much but I’m still having the increased starter effort.
Turn the key, wait for my GP relay clicks, turn it over a couple seconds, kinda stumbles like it wanted to start but dies. Kill the power at the key, wait a couple seconds, repeat starting process, takes 2 or 3 tries doing this, then starts and runs normally.
Before fooling with the IP screen filters it started up right away...
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Sounds like fuel is bleeding back... the restricted IP outlet is supposed to prevent that; and since you disturbed it that would be my next suspect (the outlet banjo not completely sealed). If it restarts easily unless it's been sitting a good while it wouldn't have to be that prominent of a leak. And if the inlet isn't quite sealed it could be pulling a bit of air.
Re-used crush washers.... (I did the same thing).
 
sk66 said:
Sounds like fuel is bleeding back... the restricted IP outlet is supposed to prevent that; and since you disturbed it that would be my next suspect (the outlet banjo not completely sealed). If it restarts easily unless it's been sitting a good while it wouldn't have to be that prominent of a leak. And if the inlet isn't quite sealed it could be pulling a bit of air.
Re-used crush washers.... (I did the same thing).
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Yeah I’m probably going to see if I can get a little more umph on that out banjo bolt. Need to find a better socket/extension combo to get seated nice and square on the head...it’s dodgy getting to it even with the oil dipstick removed. Might as well go ahead and remove it completely again and at least hit the crush washers with a torch to give them some squish again.
 
Regarding your new starting trouble: try pumping the fuel filter pump before starting the engine. If it starts right up, that would confirm that the problem is air leaking into the IP.

DelicaStuff said:
Yeah I’m probably going to see if I can get a little more umph on that out banjo bolt.... ...atleast hit the crush washers with a torch to give them some squish again.
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I'd start by annealing (or replacing) the washers, and leave overtightening the banjos as a last resort. Banjo bolts give me the heebie-jeebies.
 
Growlerbearnz said:
Regarding your new starting trouble: try pumping the fuel filter pump before starting the engine. If it starts right up, that would confirm that the problem is air leaking into the IP.


I'd start by annealing (or replacing) the washers, and leave overtightening the banjos as a last resort. Banjo bolts give me the heebie-jeebies.
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Couldn’t agree more on the banjos...which is probably why it may be getting air, I was conservative on the original tightening. Ran it down and gave it just a bump past full rundown....which will for sure be better practice with a crush washer with some crush left in it.
Good idea on the priming at the housing just before starting! Been working long hours the past few days so I’ve just accepted the new startup procedure for now (daily driver), at least its consistent. lol
Monday is my first day off so I’ll dive in then, cause if it’s not as simple as I’m suspecting I’ll be manic and have to figure it out right then...and I’m working 12s right now...need my Zzzzzs, and I’ll obsess over it.
Being logical about the whole thing it makes most since that it will be the issue, nothing else was tinkered with that would cause it.
Thanks for the help and suggestions guys!
 
Hello, I'm having the same issue on my 2.8 Pajero. Before, it used to go past 3500 RPMs no problem. Now it's as if I'm capped at around 2800-ish RPMs; it pulls nice from 1500 (with the boost compensator diaphragm adjustment). I'm suspecting a lack of fueling as well (not noticing much smoke as well). the fuel filter was changed around 8000k ago; the previous one seemed like it was a factory filter :oops: (since 1999 lol), I even found brown fuel in it. So I will be looking into that small screen at the pump inlet (Not sure of its location, but I'll try and find it).
 
parttimewizard said:
Hello, I'm having the same issue on my 2.8 Pajero. Before, it used to go past 3500 RPMs no problem. Now it's as if I'm capped at around 2800-ish RPMs; it pulls nice from 1500 (with the boost compensator diaphragm adjustment). I'm suspecting a lack of fueling as well (not noticing much smoke as well). the fuel filter was changed around 8000k ago; the previous one seemed like it was a factory filter :oops: (since 1999 lol), I even found brown fuel in it. So I will be looking into that small screen at the pump inlet (Not sure of its location, but I'll try and find it).
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Inlet may have a screen, outlet/return definitely does... either being plugged causes problems.
 
Does anybody happen to know the torque specs for the inlet and outlet banjo bolts? Or could you point me in the right direction? I’ve looked at a few fuel system manual online and checked every post pertaining to IP banjo bolts on this forum and I still can’t find it. Also, when removing both of these, do I just need to bleed the outlet?
 
Jackson Hellums said:
Does anybody happen to know the torque specs for the inlet and outlet banjo bolts? Or could you point me in the right direction? I’ve looked at a few fuel system manual online and checked every post pertaining to IP banjo bolts on this forum and I still can’t find it. Also, when removing both of these, do I just need to bleed the outlet?
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18-24Nm; 13-18ft.lbs.
I would bleed the inlet first and then the outlet... no point pushing an air bubble at the inlet all the way through the pump. BTW, yiou probably don't need to be too concerned with it... the system is pretty good at bleeding itself of small amounts of air.
 
Hell yeah, I've been chasing a rough idle problem and decreased power. The outlet banjo screen had a bit of a buildup; seems to be accelerating better and engine is a lot less shaky. That's good to know about the IP bleeding itself. A lot of people make air in the fuel system sound like a nightmare.
 
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