Injection Pump Loses prime?

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TeamSpatula
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Injection Pump Loses prime?

Postby TeamSpatula » Thu Jun 28, 2007 9:02 am

OK, so I learned long ago that you can't have just one VW, be it aircooled or diesel apparently too.
:)
So I'm looking at another 81 Rabbit, about 175k on odometer, and the guy says it runs fine, but after sitting for a day or two the pump loses prime. How serious is that? What all is involved in fixing it?
If it's not too bad, I may jump on this one for a backup Bunny.
:)
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82vdub
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Postby 82vdub » Thu Jun 28, 2007 9:41 am

My understanding is that there's a crush seal or a seal (I believe on the outlet side) that goes bad. You can replace this seal, but it's probably only a short time before the IP starts leaking from the ultra low sulfer fuel and will require a rebuild anyways. I would look at this car from the perspective that you'll probably get a few miles on it, but any long term use will require a rebuilt IP. Short term you could install a low pressure inline fuel pump to keep the IP from loosing prime. My winter car last fall began to loose prime. I installed the inline pump, IP is now sweating, so it's only maybe another year and I'll be rebuilding the IP on it or stop driving it.
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Losing prime ?

Postby hagar » Thu Jun 28, 2007 2:00 pm

Not usually serious. ---and simple to correct.

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Postby 3Bunnys » Fri Jun 29, 2007 8:47 am

I'll ditto Hagar...... Losing prime indicates a leak in your IP... If there is any indication of dampness (fuel on surfaces) on IP it has a leak.
Quick check...remove fuel outlet bolt, on top of pump, holds a banjo fitting with two hose barbs, one goes to fuel return lines from injectors, other goes to slightly large hose that is fuel return to tank. Don't loose copper sealing washers. Get brite flashlight and LQQk in pump, if you see pump internals and not fuel then you know you have a leak... BTW,, this is the place to pour in fuel to prime pump.
Personally I would plan on sending pump for reseal and rebuild, I would rebuild injectors and I would absolutely no questions asked replace timing belt and idler!!!!

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prime

Postby Fatmobile » Mon Jul 02, 2007 4:38 am

The small lines between the injectors can let air in and cause you to lose prime too.
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Re: Injection Pump Loses prime?

Postby StevenPH » Wed May 11, 2011 10:41 pm

Hi all, newbie with an 89 Jetta 1.6D here. Thanks for having me.

This is an old thread but i am having these same issues. I have almost troubleshooted my way down to sending out the pump to be resealed. Any tips on who/where I can get this done? How much it might set me back? How long I might have to live without my daily driver?

Thanks in advance for your help,
'89 Jetta 1.6d

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Re: Injection Pump Loses prime?

Postby 82vdub » Thu May 12, 2011 8:51 am

I've you've checked for any fuel line connection leaks and bad connections (both the supply and return lines), then you may have an enlarged front pump shaft bushing. A local Bosch diesel service center will be able to rebuild it for you, but it may cost you north of $800 to get it done. Maybe less and maybe more.

To try to get the car more usable for a little while longer, you could try installing a low pressure (3-5 psi) and low GPH flow pusher pump to push fuel to the IP. I did this on my old winter Jetta that had the same issue and ran it another 4 years until I parked it because of major rust issues.
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Re: Injection Pump Loses prime?

Postby StevenPH » Thu May 12, 2011 12:22 pm

I'm still hoping to solve the problem in the lines - I replaced all of the return lines of of the injectors and the end cap. Two were definitely leaking (air bubbles on one when running). but their replacement hasn't improved performance or the puddle underneath. I'm still noticing some fuel around the far passenger side injector, I tightened the nut that connects the fuel line and it still seems to be leaking near that connection. I assume the next step would to replace the fuel line and the nut?

I am far from affording an 800 dollar rebuild - and I'm not totally conviced it needs done yet, I've yet to see a definitive leak or wet area on the pump, I just have read a lot of posts here about these problems leading to potential reseal and wanted to know how nerous I should be about that prospect :)

I'll let you know how it turns out, thanks!
'89 Jetta 1.6d

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Re: Injection Pump Loses prime?

Postby 82vdub » Thu May 12, 2011 1:11 pm

Don't just blindly keep tightening the injector line nut. If the injector line isn't properly seated in the injector, it will leak and tightening the nut will cause the line to break. Most leaks at the injector are probably due to a leaking return line going to a barbed fitting.
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Re: Injection Pump Loses prime?

Postby mtran » Thu May 12, 2011 3:20 pm

perhaps this
http://www.vwdieselparts.com/forum/viewtopic.php?t=6694,but
use LOT of search how and what to do BEFORE start.Took me 2 day`s first,last time they said
40 min from car and on again,IDI one`s of corse.
I`ll improve my English

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Re: Injection Pump Loses prime?

Postby damac » Thu May 12, 2011 5:47 pm

I have had this annoying problem ever since I brought my jetta home. I have done certain things along the way that made it look like I solved it for a short time.

Right now there is a pocket of air that sticks around from the line from the filter to the pump. The return lines seems to stay the same. I have seen a single small bubble shoot from the pump back to the filter.

And behind the filter, all my fuel will drain back to the tank by the time I come out the next morning.

I just recently replaced the fuel filter with a name brand, completely replaced the fuel lines and hard plastic rails under the car and this still goes on.

I have tried inspecting all around the injection pump when hot and cold with a magnifying extension tool and can't catch a hint of weeping or a drip. It did this on 2 pumps which are older and seem to work ok, but I did a simple external reseal on.

I even put some bio safe check valves on the lines after deleting the stock water seperator under the car and it would still drain back.

Right now I think I get an annoying stumble on startups but I can drive the car around just fine. So for me I find it very annoying and would like to tackle it, but it seems I would have to start fresh with a rebuilt injection pump. I have even blown out all the lines and cleaned things up at the back end and all seemed to hold pressure, etc.
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Re: Injection Pump Loses prime?

Postby Fatmobile » Thu May 12, 2011 10:33 pm

Since you are seeing air rush back toward the filter,.. a vacuum gauge might help you find the problem.
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Re: Injection Pump Loses prime?

Postby StevenPH » Fri May 13, 2011 9:22 am

So after reseating the fuel line connection to the injector the leak there is gone, but I am still having the same issues.

Here's what I got:

Lost prime after less than a half hour sitting

large puddle of fuel leaked overnight (can't locate the source yet but it's directly under the inj. pump)

terribly inconsistent idle - it fluctuates between extreme low (I stalled out twice this morning on the way to work), and extreme high (to high for smooth shifting)

when I accelerate out of the idle, it refuses to be consistent, sometime waiting two or three seconds before rpm's catch up with where Ive depressed the pedal to.

Thoughts? I found a place that can reseal my pump for 500, Which Ill do only if i'm dead sure it's the pump. I also have potential access to a pump from my old 81 caddy that worked great. Would that be compatible with an 89 jetta?

Thanks for your help
'89 Jetta 1.6d

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Re: Injection Pump Loses prime?

Postby Quantum TD » Fri May 13, 2011 12:50 pm

The pooling around one injector may indicate a leaking injector body. You can disassemble the injector, clean the crap out of it, and reassemble to 55 ft-lbs of torque (head to injector body).

If you're getting a puddle of fuel, it likely is the o-ring between the distributor head (cast iron part) and the aluminum body. Only that seal will cause serious puddling of fuel. Either way, you need a complete reseal (or ideally, rebuild).

User name "red---rider" on ebay used to do reseals for about $150 shipped both ways. But I'm not sure he's doing it anymore. I contacted him a few months back and he said he would still do them, but had been traveling a lot. You can use the "advance search" function to "search by seller" and find him. He's in NC.

There's also a shop in Memphis that does rebuilds and advertises on ebay. $375 for a rebuild ain't bad at all. Though, there may be delays due to the flooding, so I'd call first. I've used the reseal guy, and a friend had his TD pump done at the place in Memphis. No complaints on either end.

$500 for just a reseal is a ripoff. As noted above, you can get a complete rebuild for less.

The pump off the 1981 will work, but you're sure to be in the same situation in a few weeks/months, unless that used pump has been resealed. It's not a question of "IF", but rather "WHEN" an old pump will start leaking. I thought my 1984 pump had avoided it. I sold the car about 3-4 year ago and have done maintenance on it for the guy who bought it. It lasted about 4 years on the new ULSD before it gave up. I'm resealing it right now.

Speaking of which, if you wanted to do split in costs, I have a pump I "rebuilt" and resealed. It hasn't been calibrated like a real shop would do, but it was a running pump that I completely disassembled, cleaned internally, and resealed. I've done quite a few with great success. I can't guarantee MPG though, since they haven't been calibrated to the new fuel.

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Re: Injection Pump Loses prime?

Postby StevenPH » Fri May 13, 2011 3:45 pm

Ah I see, i had thought that a reseal had to also involve a rebuild. The local 500 quote i got was for both. If the leak proves to be the I may try do the reseal myself - i've been referred to a DIY online that breaks it down fairly simply for an amateur like me. Is this dangerous ground for a newbie to venture into?
'89 Jetta 1.6d


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