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Discussion Starter · #1 ·
I recently had the fuel pump replaced on my 2.5 n/a. I noticed the old one had some wires that seemed to hold the lever on the fuel pump at a certain position. This one is all the way up. For a few days after the fuel pump replacement I didn't notice anything different, however now it feels like I have lost some power and I get some slight engine bucking (the vehiclecseems to jerk a bit 3 or 4 times) at speed when I shift from 3-4 or from 4-5. (I should note that it has also been about 90 degrees recently and was in the 60s-70s until now) i have also noticed that the exhaust creates a low booming drone that is much deeper in pitch that it used to be. At idle the engine doesn't sound any different. I have a fuel filter on order and am going to top the tank off (1/2 full) with diesel from a different station and see if that helps at all. I also replaced the air filter. What's more at idle the engine and exhaust produce a more uniform "bup bup bup bup bup" sound than they did before the new fuel pump.

Does anyone have any suggestion on what else it could be or what I should check? I saved the old fuel pump. There wasn't anything wrong with it other than leaky gaskets, so for the $35 I figured I would just replace it.
 

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The bucking is the result of fuel starvation and as Dave suggests, a suction side air leak is the likely cause.
 

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Discussion Starter · #4 ·
Sounds about right. What's the best way to find where that is coming from? If it's an easy fix I'd rather do it myself than drop it back off at the shop that did the work.
 

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Discussion Starter · #7 ·
Update:

Tightened the pipes going into the fuel pump about 1/8 of a turn. It's definitely a little more quiet and the bucking is almost non existent. All the fuel filter connectors were tight. Going to check the fuel pump next. However, I still seem to have the problem where in 4th Gear it barely accelerates with my foot to the floor on a very slight incline. 2nd and 3rd seem fine. There also sounds like what could be a slight misfire coming from the exhaust. It sputters occasionally while driving. The glow plugs only have about 1000 miles on them. I also put a half a tank of fresh diesel in last night and some diesel kleen. Ordered a timing belt and pulley last night, going to have that changed and the timing checked in the next few weeks.
 

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Discussion Starter · #10 ·
Ah that leads me to my next question... I got a new filter. What's the correct protocol for replacing it? This is my first diesel. It's an interesting experience.
 

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Discussion Starter · #13 · (Edited)

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Discussion Starter · #15 ·
Update #2.

OK I thought this was an anomaly but after today...

It seems the bumbling/puttering engine and bucking happen after i park for an extended period (hour or so) on an uphill incline. After leaving it over night in the driveway it is fine. However, a warm engine and an incline seem to be causing this. Any thoughts on that?
 

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Discussion Starter · #18 ·
You still havie an air leak in your fuel system. Change out the filter and pay close attention to how it goes back together. I would fix your problem before adding any more variables (snorkel).
OK. I can disconnect the snorkel for the time being at the filter. I may drop off the fuel filter with the guys who did the fuel pump job. They mostly work on old diesel VWs so they're good with pressurizing the fuel system. I guess they didn't think they needed to this time since it started right up.

------ Follow up post added June 15th, 2015 07:12 PM ------

Have you recently added a snorkel?
Yes, but this started before that. It actually seemed to get better after I did.
 

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Fuel filter

Somehow, I knew it would be. Thanks much! It's the old filter in a can style.

Oh boy. After reading that... I might just leave it to the professionals or swap out the filter head for the spin on type. Time to dive into the shop manual.
Changing the fuel filter is not that bad really, if it is the one fits between the top & bottom.
Use some container underneath like a yogurt container seems to squeeze in there about right.
Also gives you time to check your fuel lines etc.
 
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