Change in design of TFSi engine. Important issue with fuel pump and engine wear

Discussion in 'Leon Mk2' started by Al, Jun 4, 2008.

  1. sportbilly

    sportbilly thinking out loud

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    You've got to make sure its precisely the same thickness/size etc to the original surely, the fuel system has got to be setup to specific values and thickening the follower would surely have an effect on other bits...
     
  2. MrT

    MrT Stole my radio!!

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    One thing i would say and that nobody as far as i can see has mentioned, is that you must set the engine to TDC (top dead centre) before attempting to withdraw the pump!

    I have the APR pump fitted and from memory no mention of TDC set is in the installation guidelines!
     
  3. Makefish

    Makefish Guest

    I posted the following on Briskoda back in April but thought you guys may be interested........................

    For those of you running modified MkII Octavia vRS's you will no doubt be aware there is a modified high pressure fuel pump or fuel pump internals available to eliminate a common issue known as 'fuel cut'. There have been some reports, mainly from USA that as a result of installing this revised pump excessive wear on the cam follower (a small 'bucket' which sits between fuel pump piston and cam) resulting in catastrophic failure of both cam and pump and therefore an expensive repair bill!

    Today we removed and replaced mine to see what the effects have been running the new fuel pump for the past three months and approximately 6,000 miles with the uprated pump (24,000miles in total ie. 18,000miles with OEM fuel pump internals). The following pictures show that wear has thankfully been minimal to the point of being almost perfect which is very good news for those of you who have installed this upgrade, the only noticable wear is on the inside where the piston touches but this could be seen as normal although atm we do not have anything to compare it with (if you are considering this modification it would be helpful to see pics of the cam follower from a stanadard car before replacement).

    The conclusion mainly drawn from this would be to regularly inspect the cam follower for signs of excessive wear and keep a replacement 'just in case' as these are a lot cheaper to replace than the consequences of possible failure!

    [​IMG]
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  4. Igor23

    Igor23 Growing old disgracefully

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    Just had mine fitted by JBS, very nice chaps, no wear on the follower at all, and it's smoothed out the lumps and jerks no end, and holy s**t, does it fly, now for stage 2+ :D:D:D
     
  5. Gary@Cookies

    Gary@Cookies Full Member

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    Is it possible for this wear to cause a tappet type noise on tickover? We've got a customer with a lowish mileage 07 Cupra who has a noise we simply can't pin down, we've replaced the fuel pump, tried replacement injectors and all the usual tricks, we've had VAG technical on the case and they're puzzled too so we're doing plenty of head scratching and getting nowhere fast.
     
  6. MitraShark

    MitraShark Newbie

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    Was yours cam follower with too much wearing? Did you changed your fuel pump?

    Thanks!
     
  7. Igor23

    Igor23 Growing old disgracefully

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    Yes the pump has been changed and the follower has no visible wear...
     
  8. Kevo

    Kevo Full Member

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    Does anyone know if the cupra will be getting the more efficent engine that the gti's and s3's seem to be getting now?????
     
  9. Al

    Al Senior Member

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    Which GTi's and S3's are getting what more efficient engine?

    There is an updated TFSi engine which does not drive the fuel pump from the camshaft, but as far as can be seen it is not yet out in the GTi, Pirelli, S3 or Cupra yet.
     
  10. Igor23

    Igor23 Growing old disgracefully

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    I think that Kevo's referring to the new TT with 275/7 bhp, same engine, different map...
     
  11. sportbilly

    sportbilly thinking out loud

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    Are you reffering to the now labelled TSI which has the CAM chain, different drive fuel pump.

    From what I heard if you order a GTI now you will get this new engine, its available in the Passat.
     
  12. Al

    Al Senior Member

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  13. Kevo

    Kevo Full Member

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    Yeh think thats the one read something about it on tyresmoke...
     
  14. CupraSport

    CupraSport Full Member

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    Did you get an answer on this?

    Asked the dealer to check my car prior to delivery..
     
    #34 CupraSport, Jun 24, 2008
    Last edited: Jun 24, 2008
  15. Poverty

    Poverty Guest

    Audi has added the new EA888 family 2.0 liter TFSI engine to the Audi range. The new EA888 family is already in some of the current 5th generation Volkswagen Golf GTIs rolling off the production lines, and is based off the new 1.8 liter TFSI EA888 engine.

    the engine gains Audi’s Valvelift technology that made its debut on the normally aspirated 2.8 liter FSI V6. Audi Valvelift gives the engine two different valve lift profiles on the intake side. The lower cam profile actually opens the two intake valves at two different lifts with one higher than the other to deliberately create a swirl and tumble flow effect for intake air at low RPMs. At higher RPMs, a high lift cam takes over for more power.

    Despite the high performance, a combined cycle test for fuel economy results in a consumption of only 5.5 liters per 100km.

    Apparently, what makes this different from the EA113/827 version(s) of the 2.0 TFSI powerplant is that this one now has a higher-pressure turbocharger up to 150 bar with the unit being a BorgWarner K03 turbocharger.

    Good news is that the compression ratio is just a 9.6:1 (which means it's not that thirsty for fuels with octane ratings of 100 and above).
     
    #35 Poverty, Jun 26, 2008
    Last edited by a moderator: Jun 26, 2008
  16. Smiler-MK2

    Smiler-MK2 Fear The Inferi

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    Here is some info i found on the MKv website
    Thought i would post it here
    Happy reading

    Here's the explanation of the fuel cuts as described by Keith@APR


    Well, here's the situation with FSI's and recalibrations.

    Typically, VAG turbo engines, 1.8T, 2.7T etc. have plenty of fuel available to realize the full potential of the oem turbocharger. This is not the case with the 2.0T FSI.

    The FSI uses a rail pump in addition to the intank pump to deliver fuel AND pressure to the fuel rail. This rail pump is cam driven and moves a piston up and down to force the fuel into the rail. Deisel engines have been using this method of fuel delivery for many years. The rail pump generates pressure behind the fuel injectors and when the ecu tells the injectors to pulse or open to inject fuel into the combustion chamber a small amount of pressue and fuel is lost from the rail and the rail pump must then force more fuel into the rail to bring the fuel volume and pressure back up to spec. Simple.

    Basically, because the rail pump is driven by the cam shaft, the rate at which the rail pump is able to rebuild pressure and volume in the rail is determined by how fast the cam shaft is spinning or forcing the piston in the rail pump up and down. So the limitation in fueling for the FSI is greater at lower rpm's and in the midrange than in the higher rpm range where the cam shaft is spinning faster.

    Now you could say, well at higher rpm you are also using more fuel so why isn't the problem occurring there as well? The answer is because the rate at which the fuel pump delivers fuel increases beyond the engine's ability to consume fuel with the oem turbo at higher rpm's. Basically, the turbo provides too much power in the low and mid range than in the upper range as matched to the rail pump. The turbo runs out of breath still in the higher rpm's so fuel demand is less. Peak hp numbers are made up top as a product of torque over time where the rpm's are greater. More rpm's, more torque over time accumatively, less immediate demand on the fuel delivery.

    In the low and midrange, the fuel demand is all in torque or immediate requirement over less time. The rail pump simply can't get to a great enough speed to deliver the fuel that is demanded at peak torque rpm's. This is a very brief and momentary demand in relation to a sustained continual demand that hp requires in the high rpm's.

    So what happens is when the ecu is calling for more fuel pressure a very temporary situation can occur where the pump is not spinning fast enough to provide the requested fuel pressure in the low and mid rpm's. This results in the ecu enabling a safety feature that cuts spark and fuel temporarily to allow the pressure in the rail to build back up. This is the fuel cut some are experiencing. This is an electronically controlled safety measure that in no way means you are running lean or any threat to damage of any of your engine components may occur. The ecu is merely asking for more time for the rail pressure to build back up.

    Now knowing this, how do calibrators still extrapolate the full potential of the turbocharger in the low and mid rpm's?

    There are a couple of different ways and philosophies to accomplish what everyone wants, the most power possible.

    APR's engineering team chooses to follow the recommendation of Bosch, Audi and VW engineers of maintaining the oem specified air fuel ratio of 10.5:1. The reason for this requirement is that direct injection engines run a higher compression ratio over standard injection engines due to the benefits of FSI which results in higher exhaust gas temperatures. Turbocharged engines have always resulted in higher egt's that wear the head, exhaust valves, exhaust manifold and turbocharger itself more rapidly than a normally aspirated engine will. Engineers have combated these higher temperatures with sodium filled valves, high nickel content manifolds and inconel turbo housings, etc. The best strategy for controlling high egt's however is richer afr's to cool everything down in lieu of expensive parts that oems can't typically provide at a reasonable price. So unless you plan on changing out your valves, exhaust manifold, turbocharger and even the headgasket, you can only maintain safety to your components by maintaining the OEM specified afr's.

    What this means to APR clients is that APR is doing everything within the reccomended specifications of oem teir 1 suppliers and VAG/Bosch engineering reports to ensure no deterioration of life occurs to any of your engine components. This results in greater demand of the rail pump and to maximize the potential of the turbocharger at low and mid rpm's, fuel pressure must be maintained and this is much more difficult at the oem recommended afr spec as opposed to merely leaning it out and watching the egt's climb but no fuel cuts will occur.

    Other companies have chosen to lean out the air fuel ratios to as much as 12.5:1 to avoid the fuel cuts. This results in egt's that are well above Borg Warner's specification of 970deg cel max preturbine egt's. This spec was put in place by BW for VAG engineers to ensure no loss of life to the turbocharger. During BW's testing and development of the turbo's found on VAG FSI engines, egt's outside of their spec was proven to show accelerated wear and even total failure well before the normal lifespan of the turbo as per its design requirements from VAG.

    EGT's are so important to FSI engines that Bosch, at great expense, integrated an egt model into the ME 9 ecu to calculate preturbine egt's. If the egt's climb out of spec as per the ecu's model, the ecu then dumps fuel to cool everything down for a period of time until the egt's come back to spec. This is known as the hardware protection map to most engineers familiar with Bosch EMS.

    APR engineers find themselves walking a fine line between maximum power output and safety. APR WILL NOT lean out afr's that result in egt's outside of the specification. APR WILL NOT provide an irresponsible product to the marketplace.

    This philosophy results in a difficult position in the marketplace as our competition chooses to ignore these basic engineering principles and recklessly provides products that are known to result in loss of life of your engine. They don't hit fuel cut because they are running leaner mixtures that result in less fuel demand and therefore less demand on the rail pump at the low and mid rpm's. EGT's however, are not safe at these afr's. APR recalibrations will always maintain safe egt's and if they do climb out of spec the hardware protection map will kick on and bring everything back very quickly. Our competition circumvents or disables hardware protection and allows the egt's to continue to climb.

    This is not merely speculation or arguable. It is proven fact. To satisfy yourself, please data log lamba, egt's and fuel pressure. This is especially concerning for track enthusiasts that find themselves hot lapping during driving events or participating competitively. The street enthusiast may be able to get away with higher egt's for longer periods of time as typically you are at wot in relatively short bursts where on a road course you are wot almost the entire time. All client situations must be considered and please know that with APR calibration you will enjoy safe operation in any circumstance.

    Now that we understand why the fuel cuts occur you may ask well, what is APR doing about satifying the concern as fuel cut is not fun.

    We have discovered opportunities in the ecu to increase fuel pressure from 110 bar to 130 bar. This results in higher overall fuel pressure so the demands in the low and midrange can be satisfied by having more pressure so when the pressure dips due to the demand it will not dip as far and fuel cut will be avoided. This is a relatively new discovery that is currently being integrated into all of our calibrations. In the USA we have been offering a "beta" version of our stage 2+ programming that incorporates the additional fuel pressure and fuel cuts are greatly diminished and only occur very rarely with significantly more power delivery in the low and midrange. The testing is complete and we are now working to provide new files with absolutely no fuel cuts but with almost all of the power available to be had by the oem turbo.

    Further development has resulted in a new higher capacity rail pump that will be the ultimate end all be all to the fuel cut problem. The addition of the APR rail pump results in 15-20 more hp and 20-25 more lb. ft. of torque over the beta file in the mid and low rpm's and the oem turbo is fully optimized.
    "
     
  17. bqd

    bqd need some chocolate

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    hmmm so let's get it straight...
    New revisions of engine which have pump operated from exaust camshaft don't have rail pressure problem?
     
  18. Saul

    Saul <b>SCN Admin</b>

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    all SEAT 2.0t engines use the cam-pump (i think a newer engine does not but not seen in SEAT's yet)
     
  19. Al

    Al Senior Member

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    Yep they do. However you would have thought the manner of driving a pump froma camshaft would be the same whether it be on the inlet or exhaust camshaft? You must have the new engine then. Which model do you have?
     
  20. Chris_Cupra

    Chris_Cupra Full Member

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    What is the car that you're expecting ...??? A Leon ...???
     

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