Intermittent Fuel Cuts – Low Pressure Fuel Pump

August 17, 2011 Update: 

It seems that the CL part number has now been superseded by 1K0 919 051 DB. I don’t know what the changes are or if the change was spurred by a problem with the CL number. Info from this thread.

As the 5th generation cars begin to age in the U.S., a couple of newer problems are beginning to rise up.  One really annoying problem is the low pressure fuel pump cutting out intermittently.  It leads to the high pressure fuel pump starving of fuel and then the engine loses power for a few seconds.  Utterly annoying and it can be dangerous if you’re traveling at a good rate of speed and happen to slow down in the far left.  It can be difficult to get onto the shoulder.  It tends to happen during a long drive in hot weather.

A newer updated pump (Part Number : 1K0 919 051 CL) is supposed to help with this problem.  This is not located in the engine bay, unlike the high pressure fuel pump.  This one sits underneath the rear seats.  It is easy enough to replace and there are a few DIY’s floating around.  Here’s a good one from the Golfmkv forums – In-tank fuel pump replacement has the best price that I’ve seen so far at $180 dollars plus shipping.

Before changing the fuel pump though, you might want to check whether your thrust sensor has been updated to the latest revision.  This sensor sits on the passenger side of the high pressure fuel pump.  06E906051K is the part number for the newest thrust sensor revision.  If this solves your problem, you’ll have saved around 120 dollars.

06E906051K Thrust Sensor

A New Look For The Site

I’m mixing things up a little bit with the site layout.  That image above, totally relevant.  The layout is going to be changing a little bit over the course of the next few days.  Is it good, bad, gives you a headache?  Suggestions are completely welcome.  I’ll promptly reject them and lord over my complete control (juuuuussst kidding…kinda). Most of the the joking aside, do leave me a comment and let me know how it makes you feel.

BSH True Seal Intake

Original article circa summer ’09 – I’ve split the article into its two components: the intake and the diverter valve kit.

This kit is for the 2.0 T FSI engine.

I received this intake kit awhile ago.  The design is top notch and well made.  It includes single piece piping, a heat shield, a proprietary filter, a Forge diverter valve and all necessary clamps and hoses.  Installation is relatively simple if you have the proper tools.  One highly recommended tool is a hose clamp remover.  I think the newer kits are being shipped with them.

After a few months with this kit, I feel that this is the best intake for the GTI out there right now.  It solves the issue of failed diverter valves and relocates the valve itself to the front of the car.  No dyno runs on the intake yet but midrange and the top end feel better.  The torque curve seems to have shifted slightly to the right, but nothing crazy.  This intake is not very loud, if you are looking for noise, look elsewhere.  Otherwise, it’s a nicely designed piece and a great company to deal with.

If you are chipped, you don’t have to worry about any more torn diverter valves.

Review Redux: updated (1/27/2011)

The BSH Trueseal intake for the FSI engine is just one of many intake systems available for the GTI.  There isn’t much deviation as far as filters on a stick go but this one offers a few unique features of its own.  It offers a built in relocation bung as well as a heat shield which isolates the filter from the engine bay.


Sorry for the horrible picture, a much nicer one will be up soon, I promise

The intake itself is very simple with 2.75 inch piping in powder coat black.  The heat shield is relatively thick sheetmetal, also powder coated black.  The edges of the heat shield are covered with a rubber seal that presses up against the hood liner, thus creating a box around the filter.  The silicone and associated clamps are all high quality pieces.  The filter is a proprietary specification that is narrower than most other filters in order to fit into the heat box.  Despite that, a similarly sized filter from another vendor will most likely fit.  It is oiled but I have not had any problems with the oil contaminating the maf sensor.  It has since been changed out for an AEM Dryflow filter which filters better and requires no oil.

I can’t really comment of how much power this intake makes as I have not put my car on the dyno with it.  You’ll probably gain a few horses, nothing to write home about.  Those gains will increase as you pile the mods on though, especially with chipping.  Just don’t believe the +15 hp ads that you see regarding intakes.  It does wake up the engine a little on the high end and provides a very nice sound.  It’s not loud by any means, so if noise is what you want, look elsewhere.  BSH’s intake provides a very mature sound, no doubt due to the heat shield surrounding the filter.

Here’s something important, and since it’s important, it’s going to get its own break.  MAF sensor placement is very sensitive on these cars.  Some intakes will drive the sensor nuts and in turn your car, causing all sorts of chaos.  Fuel trims are adversely affected by incorrect maf calibration.  STFT and LTFT (short term and long term fuel trim) will be incorrect if the maf placement on the intake is off.  There was an early run of BSH intakes that had incorrect maf holders.  The fuel trims are not too bad on these early intakes but in reality you want it to be as close to zero as possible.  If you buy used, be sure to know which version you are getting.  The older maf holder sticks out about an inch or more from the intake.  The newer ones are much closer to the piping.  Reference the following picture of the older MAF holder:

The newer one is much smaller than that.

Older BSH MAF Holder

Finish is not BSH’s strong suit.  The intake is well made and will hold up but doesn’t look the part.  I know it’s nitpicking but it’s all part of the show.  The welds on the intake are very visible and lend a homebrew look to the whole thing.  The relocate bung is sealed with an ugly vinyl cap if you’re not using it.  The rubber seal on the heat box looks like it came straight from your local hardware store.  The intake also doesn’t secure too well in the box.  I eventually added additional rubber to secure it.  There is certainly none of the flash you get from other manufacturers such as AWE, Eurojet, Forge and APR.  If you’re looking for flashy, this isn’t the intake you’re looking for.  For those that are looking for functional bits, this is it.  It has a great heat shield, a built in relocation port and all the growl a normal adult needs.  Despite the visual flaws, the BSH intake still gets a recommendation from me.  It is priced far below the other premium intake options such as the Forge Twintake, and AWE carbon intake and works just as well.

~ 270 from and other dealers

Here’s a link to an AEM Dryflow filter that fits in the BSH heat shield.  The fit is a little tight though.  AEM Dryflow

AWE Diverter Valve Relocate – A Few Quick Notes

I’ve had a few days with the AWE Diverter Valve Relocate and here are a few quick impressions:

  • Very quiet with the revision D diverter valve
  • Simple and clean installation
  • Works with any 2.75″ aftermarket intakes or stock TSI intake
  • Boost with the electronic diverter valve feels less linear than the BSH mechanical valve solution
  • Cheapest relocate solution

I’ll have more to say on it one I have spend some more time with the kit.

*Review Posted Here: AWE Diverter Valve Relocation Review*

Revision D Diverter Valve

Part Number 06H 145 710 D


A little while ago, VW released a revised version of the infamous diverter valve.  Now known as the revision D valve, it replaces the diaphragm seal with a much stronger piston type.  Previous revisions (B, C, and G) had diaphragms that were known for ripping and subsequently failing to hold boost.  Some of these failures were under stock boost levels.  The G version is the stoutest of the diaphragm valves with fewer failures reported across the forums.

Of course luck plays a huge role in this.  Some people have reached 30,000 miles on the stock C valve.  I reached at least 45,000 miles on my C valve.  Then again, I tend not to use my right foot aggressively.  If you feel that your car is losing power or making funky noises, pull the valve to check.  Look for tears in the diaphragm.  If you have a boost gauge, it’s even easier for you.  The car will not hold peak boost easily or at all.

The new valve simply bolts right up to where the old one sits.  It seems to have a good track record at the forums.  There has been a report or two of it failing but the causes were unknown.  Maybe a factory defect?  MJM Autohaus currently (1/19/2011) has the best price at $65 shipped.

There are several kits that solve the diaphragm problem by using a piston type mechanical valve, or a vacuum actuated diaphragm valve.  BSH, Eurojet and AWE all sell mechanical kits.  Forge sells one that has ecu control but still relies on vacuum.  I have the BSH valve relocation myself, a great piece of kit but I wanted to hand control back over to the ECU.

Why try this over a mechanical valve?

  • It allows the ecu to control when and how the valve opens
  • Quicker to open when the throttle is released (mechanical valves rely on vacuum and pressure differential to open up)
  • Cheaper (65-90 dollars and no additional parts required)
  • Less hassle at the dealership (oem part)
  • Maintenance free

New piston design

There are certainly arguments for using a mechanical valve such as the ones included in the BSH diverter valve relocation.  A mechanical valve is simpler and pretty much bulletproof.  There are no electronics to worry about, they just work.  In the case of the 2.0t FSI engine (and TSI as well) the mechanical valve is also open at part throttle (under vacuum).  This allows air to bypass the intercooler and turbo and go straight from the intake to the throttle.  This supposedly leads to smoother throttle transitions.  This only works for mechanical valves used in a relocation kit.  I can’t comment on that, I’ve completely forgotten how the car first felt without the BSH kit.  With the kit on, the car ran perfectly well.  Now the exact amount of benefit this provides is debatable but the logic is sound, path of least resistance.

If you’ve tried the new revision, let me know what you think of it in the comments!

Clear Sidemarkers

Happy New Year everybody!  I’ve got a few new projects coming in the next few weeks so things will be back up and running soon.  I’ve got a an OEM S3 style relocate coming, as well as a new diverter valve setup.  Here’s a recent one I picked up on the forums.  Excuse the dirty pictures, as it’s been raining in L.A.  These are clear side markers.  I replaced my smoked ones and they blend in better on a white car.  It makes the front end look a little less busy.

Installation is super easy.  Just pop out the old ones and place in the new set.  Many online vendors sell them, such as parts4euro and bfi.  ECS sells them as well but the clear ones are supposedly susceptible to yellowing.

Clear Side Markers