Author Topic: injector pump blowing return lines  (Read 5669 times)

June 20, 2011, 01:16:03 pm

playit

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injector pump blowing return lines
« on: June 20, 2011, 01:16:03 pm »
I just got done replacing My old 1.6 ecodiesel pump with a reman turbo pump 2 weeks ago. Ever since I had it running its been building pressure in the braided return lines and blowing them off. The engine runs perfect and I replace all the fuel lines under the hood. I also blew some shop air through the fuel lines, valves and fittings to make sure they are clear.

Anyone else have this problem?

thanks, Tim B.

Reply #1June 20, 2011, 02:09:02 pm

RabbitJockey

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Re: injector pump blowing return lines
« Reply #1 on: June 20, 2011, 02:09:02 pm »
or wrong banjo bolt in the pump possibly
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Reply #2June 20, 2011, 07:08:36 pm

playit

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Re: injector pump blowing return lines
« Reply #2 on: June 20, 2011, 07:08:36 pm »
I used the banjo fitting from my eco pump.

Reply #3June 20, 2011, 07:28:06 pm

Dakotakid

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Re: injector pump blowing return lines
« Reply #3 on: June 20, 2011, 07:28:06 pm »
Or do you simply have the two banjo bolts in the wrong holes.....inlet vs. return.

The inlet is unrestricted....the outlet is reduced as I recall. Been awhile.....
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Reply #4June 20, 2011, 10:32:44 pm

ORCoaster

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Re: injector pump blowing return lines
« Reply #4 on: June 20, 2011, 10:32:44 pm »
If the banjos were  swapped I don't think it would run very well as internal IP pressure is regulated by that out banjo is it not?  I would consider drawing a vacuum on the line to the tank into some sort of reservoir and see what kind of hairball you catch coming out of it.  It should be an unrestricted flow back to the tank.

Reply #5June 20, 2011, 10:36:53 pm

fatmobile

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Re: injector pump blowing return lines
« Reply #5 on: June 20, 2011, 10:36:53 pm »
Yep, the OUT bolt should be on the output.
But the problem is most likely a plugged check valve in the line going back to the tank.
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Reply #6June 21, 2011, 03:33:27 am

Mark(The Miser)UK

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Re: injector pump blowing return lines
« Reply #6 on: June 21, 2011, 03:33:27 am »
If the banjos were  swapped I don't think it would run very well as internal IP pressure is regulated by that out banjo is it not?  I would consider drawing a vacuum on the line to the tank into some sort of reservoir and see what kind of hairball you catch coming out of it.  It should be an unrestricted flow back to the tank.

I think you'll find internal pressure not regulated by the banjo. Even the bolt with the metered hole has a limited effect. The output bolt controls the flowrate of excess fuel, for cooling of pump and warming of fuel back at the tank and anything else I haven't thought about. The regulator near the pulley dominates the internal pump pressure. Otherwise accidental blockage of the output gauze would lead to an exploding pump.

If the  output of the banjo back to the fuel tank gets clogged [not sure how] then back pressure will enter the push on lines on the injectors, and cause them to leak etc. If I remember correctly, the orifices on that banjo are sized about 20 : `1 or was it 30 : 1, never seen anyone able to swap those lines over, as to get a 1/4"od, 1/16" ID rubber hose over  a 3/8" barb would take a skill beyond my own...


Of course I could be wrong...

EDIT  Is there something in the line going back to the tank that could  block? Blow down it? Is your system including one of those fuel preheater things that rest on top of the fuel filter and that the return fuel has to go through?
You could try running back to the tank a new return line, or for a short test run run a return from the banjo fuel line into a milk bottle.
The 'KATE' is poor on pictures of the return banjo for this setup and only shows a single barb, but doesn't show where the injector returns attach, so do the returns enter the main flow elsewhere?
« Last Edit: June 21, 2011, 05:22:45 am by Mark(The Miser)UK »
Mark-The-Miser-UK

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Reply #7June 21, 2011, 01:56:37 pm

playit

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Re: injector pump blowing return lines
« Reply #7 on: June 21, 2011, 01:56:37 pm »
I feel like such a retard....That's exactly what I did.

could I have harmed the pump?

Reply #8June 21, 2011, 03:23:55 pm

Mark(The Miser)UK

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Re: injector pump blowing return lines
« Reply #8 on: June 21, 2011, 03:23:55 pm »
I feel like such a retard....That's exactly what I did.

could I have harmed the pump?


LOL
Nah just mop up the diesel from inside the aneroid and dry the diaphragm.
Where did you conect the output from the inlet manifold? This is where the pressure would have come from if the braided lins jumped off quickly.
On the early TD setup the output banjo has 2 barbs, so not easy to swap with the single barbed inlet banjo.
Swapping bolts would indeed do as Andrew says.

For my interest, is the eco fuel draining set the same way?

On my Quantum, if I remove the injector fuel return line, from #4 injector then diesel will spurt up perhaps 5ft from the line attached to the banjo. So there is pressure there, of perhaps a few psi. I wonder if that is telling me that I have a partial blockage back at the tank?
H'mm been running OK for 2 years, without any other symptoms, other than touching the braided's cause them to leak, if  more than a few months old
 
Mark-The-Miser-UK

"There's nothing like driving past a bonfire and then realising; its my car on fire!"

I'm not here to help... I'm here to Pro-Volke"

Be like meeee: drive a Quantum TD
 ...The best work-horse after the cart...

Reply #9June 21, 2011, 05:00:40 pm

playit

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Re: injector pump blowing return lines
« Reply #9 on: June 21, 2011, 05:00:40 pm »
The banjo off my eco pump has 2 barbs. but the banjo on the eco pump is mounted were the boost arinoid is on the turbo pump. This is were I got confused lol.

I ran the vacuum line from the manifold to that rubber piece on the side of the pump under the arinoid, now I don't know what the rubber piece dose lol. But I looked at some pics online and I think I have it straightened out now.
I ran the injector return to the 2 barb return banjo, and I connected the manifold vacuum line to the arinoid banjo. It seems to be ok, I drove it the road a few times and nothings blown off.

Reply #10June 21, 2011, 07:43:46 pm

Mark(The Miser)UK

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Re: injector pump blowing return lines
« Reply #10 on: June 21, 2011, 07:43:46 pm »
The banjo off my eco pump has 2 barbs. but the banjo on the eco pump is mounted were the boost arinoid is on the turbo pump. This is were I got confused lol.

I ran the vacuum line from the manifold to that rubber piece on the side of the pump under the arinoid, now I don't know what the rubber piece dose lol. But I looked at some pics online and I think I have it straightened out now.
I ran the injector return to the 2 barb return banjo, and I connected the manifold vacuum line to the arinoid banjo. It seems to be ok, I drove it the road a few times and nothings blown off.

Ah so!  The vacuum line you speak of only has a vaccum at idle and then only if your airfilter is blocked! All other times it will be the boost pressure which up a hill should reach 10psi as standard!!
The rubber fitting on a standard turbo pump beneath the spaceship is actually the pressure equalisation vent Connect from manifold to top of spaceship...
If this is the eco pump, then the vent is where the altitude fitting connects, and there is no feedback from the inlet manifold  [or is there ;) ]
Mark-The-Miser-UK

"There's nothing like driving past a bonfire and then realising; its my car on fire!"

I'm not here to help... I'm here to Pro-Volke"

Be like meeee: drive a Quantum TD
 ...The best work-horse after the cart...

Reply #11June 21, 2011, 08:35:58 pm

ORCoaster

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Re: injector pump blowing return lines
« Reply #11 on: June 21, 2011, 08:35:58 pm »
Very informative discussion here.  Good to know that changing the IP internal pressure is changed from the front of the pump by adjusting the regulator with a punch and hammer.  Very scientific, but it works.  That was most of my cause to install a gauge on the pump.  So that teeny tiny hole in the OUT bolt is more about pressure of a different sort then.  Also good to know.  It is funny that I have two pumps and one has OUT clearly stamped on the top of the bolt and the other does not.  I wonder if someplace along the line they had confusion of which went where and had to start stamping them to clear up the confusion. 

Andrew, too much idle time?  nice drawing though.  And yeah, the banjo controls the routing of fluid and little else, the control is in the bolt portion not in the ring around it.  Good catch there. 

See how cool this forum is?  Problem solved, educated a bunch of us in the meantime.  I am liken it.

Reply #12June 21, 2011, 09:02:26 pm

playit

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Re: injector pump blowing return lines
« Reply #12 on: June 21, 2011, 09:02:26 pm »
This forum never fails to answer my questions.

You guys are awesome!

thanks everybody.

Tim B.

Reply #13June 22, 2011, 03:47:35 am

Mark(The Miser)UK

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Re: injector pump blowing return lines
« Reply #13 on: June 22, 2011, 03:47:35 am »
Very informative discussion here.  Good to know that changing the IP internal pressure is changed from the front of the pump by adjusting the regulator with a punch and hammer.  Very scientific, but it works. 



If rather than a punch, you use a small bolt with a nut on, you can limit the amount of movement of the pressure adjuster, as it may have years of stiction to overcome.
The blunter the punch the better, otherwise I assume it's possible to swell the adjuster.

So... following my own advice, I'll make sure the little bolt is flat on the end and not countersunk  ;D
Mark-The-Miser-UK

"There's nothing like driving past a bonfire and then realising; its my car on fire!"

I'm not here to help... I'm here to Pro-Volke"

Be like meeee: drive a Quantum TD
 ...The best work-horse after the cart...

Reply #14June 22, 2011, 07:05:32 pm

ORCoaster

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Re: injector pump blowing return lines
« Reply #14 on: June 22, 2011, 07:05:32 pm »
Is stiction a function of gripshun or is it a derivative of it?  I can never seem to keep the two straight. 

I second the blunt punch deal.  I have a large set and actually have one that fits pretty much tight in the opening.  So smacking it, I mean lightly tapping on it, is pretty well flat on.  Now that I have the gauge I don't have to go the nut and bolt route.  Well, I did go that route but I drilled out the bolt and soldered the nut on top and ran the OUT bolt into the nut with the banjo squeezed on top of the nut.  The gauge uses another banjo take off I heisted from the auto wreckers.