MK5 Golf GTI
All Things Mk5 => Mk5 General Area => Topic started by: ZoliWorks on December 15, 2024, 09:36:57 am
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Replacing my low pressure fuel pump has been on my to-do list for a while now and 2 days ago I got the job done. I ordered a VDO pump based on Autodoc's compatibility result. VDO part number for this is 228235070001Z and it came with a black seal ring, 1J0919133B. Initially I also ordered a pump controller module but it was an aftermarket unit, not oem so I decided not to keep it. I may get a new controller sometime next year if I'll have nothing else to spend on. The difference between the new pump and old pump is that the old one has a blue top, the new one has a white top.
The inscription on the pump reads A2C53107628 and has the production date stamped in that says 2022.
The OEM rubber seal ring was pinched. I made sure to not pinch mine when replacing it. The pump was never changed as it still had the original seal tape on it that was so brittle it broke into pieces when I tried to cut it.
As for the result...
Changing the pump made no difference whatsoever. Everything is the same as it was before. Still rough-ish cold starts and air noises every time I open my door after letting the car sit for a few hours. Since it wasn't the pump, i'm moving on to the next step: injectors or my hpfp are leaking.
Around march next year, I'll be replacing my injectors with brand new OEM Mk6 R injectors so I can finish the K04 swap and remap for 340-350hp since I'm remapped for stock injectors now. If that still doesnt change anything, I'll be buying and upgrading a brand new Hitachi HPFP. If still nothing changes, then I wont try anything else since it's just the cold start, no other issues.
Update 1: HPFP replacement
https://www.mk5golfgti.co.uk/forum/index.php/topic,134567.msg1165363.html#msg1165363 (https://www.mk5golfgti.co.uk/forum/index.php/topic,134567.msg1165363.html#msg1165363)
(https://i.postimg.cc/SsJcRB5H/lpfp0.jpg) (https://postimg.cc/ZBzWDMJL)
(https://i.postimg.cc/Bn05pwL1/lpfp1.jpg) (https://postimg.cc/ykLSYjTV)
(https://i.postimg.cc/59DSYtfg/lpfp2.jpg) (https://postimg.cc/BtcKR4LP)
(https://i.postimg.cc/L6fBzMXp/lpfp3.jpg) (https://postimg.cc/8jp6S9MK)
(https://i.postimg.cc/zGFCcSK2/lpfp4.jpg) (https://postimg.cc/9Dzw49xy)
(https://i.postimg.cc/ydbWGWLb/lpfp5.jpg) (https://postimg.cc/YGQpG2K6)
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Worth a try and at least you now know that, that part is all working correctly.
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Yeah, the pump was $100 so no regrets. I'll sell the old one for $40 and I at least know that I can rely on the new one when I push for more power.
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Back with an update after driving the car for some time. Cold starts are better than they used to be but I'm still losing rail pressure when left overnight.
On the plus side, the water trickling sound that the rear of the car used to make after stopping, is no more. The old pump likely had a failed/failing one way valve so for $100, this was a great refresh/replacement.
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Good work. It was quite noticeable for me when I changed the pump. The remaining leak will most probably be the injectors then.
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Update again. Replaced HPFP with a Hüco unit. It's basically a Hitachi pump but with the Hitachi name grinded off and assembled in germany. After moving over the uprated internals, the pump seems to be more noisy than the old one under load. Cam follower was replaced with an INA part. Old one wasn't really worn out but figured might as well do it.
Now the thing is, I cant tell if it's my pump that sounds different or if my turbo has developed enough play to make noise while under load.
Changing the pump changed absolutely nothing. Fuel is still draining out of the fuel rail after letting the car sit. I'm changing the injectors with brand new oem S3 ones and installing a new oem rs4 fprv before getting remapped. Hopefully this will sort my fuel leak issues.
(https://i.postimg.cc/SRkT4y6p/huvo.jpg) (https://postimg.cc/mzpNNWpd)
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I've been searching for the long cold start on AXX-BWA for years and never found the solution. I don't want to start changing parts without a clear pad... injectors? Who knows.
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I've been searching for the long cold start on AXX-BWA for years and never found the solution. I don't want to start changing parts without a clear pad... injectors? Who knows.
I'll update this post once I fit the injectors. Ordered them today and should arrive tomorrow, but will only be fitting next week when I'm also remapping for a proper k04 tune.
I have:
- New Continental LPFP
- New Hüco HPFP with VIS Internals
Soon:
- New S3 Injectors and a complete mounting kit (seals, baskets etc)
- New Fuel Pressure Release Valve
- New Bosch N80 Valve
It has to be something on the high pressure side of the HPFP/Fuel Rail. When I unbolted the high pressure side from the pump, nothing came out. Literally 0 fuel. When I did the low pressure side, some fuel came out. The LPFP relay was disconnected for an entire day at that point so it didn't pump any fuel when I opened the door.
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Changing my LPFP made a big difference for me, as the old pump must have been worn out at 120K miles.
I am taking out my injectors tomorrow to change the baskets, seals and generally clean/service them......as been seeing loads on basket failures recently.........every little bit helps and it is preventative maintenance in my eyes.
At the same time I am also going to check on the inlet valves while it is all off as cleaned them 20k miles ago, curious to there condition as they were really bad when I did them the first time.
All parts collected and have the day off to attack it :scared: :grin:
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Another thing I've heard is that the fuel lines can develop cracks and air can get through them, into the fuel feed. If all else fails, this is also something I wanna look into. I'll replace certain parts of the fuel lines with transparent tubes just to see what's up while the engine is running.
Good luck with your injector stuff!
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Alright, back with an update, nothing changed really...
New injectors, complete injector seal kit, new fprv, new rail pressure sensor, new n80 evap valve, new lambda, new tune.
The car starts pretty much the same when cold. Spins up, hangs a bit then slowly comes to life. There's still that annoying air noise when I open the door and the electric fuel pump starts pumping.
I've legit run out of ideas at this point. The only other thing I was thinking about doing is changing the rubber fuel lines as they are quite worn out at this point.
Anyway, here's 3 clips with cold starts and then a 4th clip with a hot start
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Sounds quite healthy to me........maybe a split sec longer than mine on a cold crank, otherwise acceptable for the TFSI.......heard a lot worse than that
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That is exactly what my tuner told me, who specializes in these engines. He told me it's normal for the TFSI and that I shouldn't be trying to fix something that aint broken when it comes to these engines specifically.
edit: this is a different tuner from the one I had up till now. After I kept bugging the old one about how sh*t my car was running, he just up and blocked me cause he was also in the process of moving shop. Why did I go with him in the first place? cause I didnt know anyone who knew these engines in my area, while he claimed that he's been doing them for 20 years and because I was a broke college student at the time so money was an issue.
We went through the map with this new tuner and basically it was awful. The engine was running so lean it was literally begging to be killed. He messed with the VVT values to make the car sound louder, he messed with the ESP skid control values to make the car much more likely to spin wheels. He messed with the wheelspin part of the ESP unit, making it a hardcut limiter so every time I'd start spinning, it'd cut power, let off boost and then resume. When on the highway and using the cruise control to increase speed, the car would go into full boost, then let off boost, then full boost, then off boost again, basically jerking you back and forth as it was trying to accelerate. Under hard acceleration in 3rd or 4th gears, the car would jerk left and right, losing traction here and there, trying to drag you side to side. The engine was also overall much louder at idle, at normal driving, at hard acceleration etc. The boost was also not controlled whatsoever. He basically set the boost from 2.5k all the way to redline to be 1.55 bar. He also changed the values the gas pedal was seeing. When it was at 30%, it was giving 55%. When at 50%, it was giving 99% or something along those lines.
With the new tune the new guy reverted back to the stock N75 values, reverted back the VVT changes as I've seen the car at times go as high as 32 degrees, set the boost to 1.4 and I forgot how much at redline but much lower. He also made some changes to the ESP when accelerating so now with ESP on it feels like I'm driving on snow. I can floor it, the ESP light will flash but the car wont cut out, wont jerk, it will just get up to speed with minimal to no wheel spin. Also no more wheel hop whatsoever. The car is also a lot more quiet overall, both under full load and when just driving normally.
The only thing I dont like is how the turbo no longer makes that stututu sound when I let off the gas since that was the most unique part about it imo. Once I'm done with the anti surge core conversion, he said he'll add back the stututu.
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Sounds like that original tuner made a real mess of things.......at least it now runs more like normal now
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My Mk5 GTI cold starts sounds the same as on your videos every morning...
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My Mk5 GTI cold starts sounds the same as on your videos every morning...
I still dont think it's fine but it is what it is, I gave up. As long as it starts, it's ok I guess...
Earlier today, 12c outside, it started like a diesel at -20: It started cranking, puffed about twice, died again, then cranked for a bit more and finally started. Take a look at this video on reddit. It was basically that but 2x longer
https://www.reddit.com/r/GolfGTI/comments/1al3gxc/mk5_bwa_rough_cold_starts/ (https://www.reddit.com/r/GolfGTI/comments/1al3gxc/mk5_bwa_rough_cold_starts/)
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That does not sound right for sure.
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Okay I did not think it'd do it again, but surprise! it did... It's 16 degrees celsius outside and you've been sitting in a garage! Why cant you just be normal?!
I gave you brand new injectors, brand new high pressure pump, brand new low pressure pump, new n80 valve, new o2 sensor, the cam chain was done with all new INA parts, including the VVT adjuster and solenoid! and you've been carbon cleaned last year...
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Are you sure the timing is good still on the chain and belt?
If a tooth out on either one, that would def make a hard to start scenario
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At idle, the chain is sitting quite happily at 1.0 KW when warm but the adjuster is at 26-27 KW even when the requested is 28 KW. The belt hasn't been checked since last year but back then we checked 3 times and both marks were on spot.
I need to take a look at those VVT adjuster ring seals. Those wren't changed and they are rubber/plastic on this engine as far as I know.
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I've been chasing the same cold start issues on my Edition30. After trying various fixes, late last year I replaced the rubber o'rings in the vacuum pump on the side of the head and that seems to have done the trick. For a couple of months now it has been starting on the button, no extra cranking, no shaking and rattling into life - just a normal engine start. Try that if you haven't already?
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I've been chasing the same cold start issues on my Edition30. After trying various fixes, late last year I replaced the rubber o'rings in the vacuum pump on the side of the head and that seems to have done the trick. For a couple of months now it has been starting on the button, no extra cranking, no shaking and rattling into life - just a normal engine start. Try that if you haven't already?
Do you mean the VVT adjuster seals? If yes, then yeah, that's the next thing on my list. I already have the 3 rubber rings and the gasket for the cover, just didnt have time to do it yet.
If you mean the internal seals in the vac pump itself, I'll likely be replacing the whole pump as it's leaking and I haven't had much luck with rebuild kits.
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I mean the vacuum pump seals - seems to have done the trick for me. I think it is a pretty sensitive engine with regards vacuum etc.
I actually tried to check and replace the 3 plastic o'rings on the VVT housing myself on the weekend because I have an ongoing slight idle misfire. I also needed to replace the cam cover gasket too - Annoyingly I didn't get the whole job done, I just couldnt get the housing cover off of the VVT/timing chain area. I started to button it back up and consulted my guide again and realised that I had left 1 black bolt in the housing at the bottom and had removed a silver bolt that was right next to it in an area with no visibility, thinking I'd taken out the right one. Only realised my mistake after buttoning most of it back up, but the day was getting long and I'd had enough so I gave up - something for another day. At least it should be a shorter job in the future as I don't need to remove the cam cover again to do this job. Good luck with yours!