In reply to Slippery :
Yeah if one bleeds off pressure then they won't fire. The pressure in the rail needs to meet 300 bar before it will I assume switch the injectors on? I would think it would be obvious which one is doing that but when I pulled them it wasn't. Also when I had them set up to spray into the cups not a drop came out.
Presumably that fuel pressure sensor you were removing is what sends the signal that there is appropriate pressure in the rail to fire the injectors.
I probably missed it but I'm guessing you tested that for proper operation?
Like Slippery, this is well out of my wheelhouse (not sure anything is IN my wheelhouse at this point), just trying to be helpful.
In reply to AxeHealey :
Honestly I don't know a great way to test it yet. The fact that it's reading the same as the one before it leads me to believe it's functioning as intended.
I woke up this morning with another plan. I had seen it mentioned before to place a ball bearing at the fuel outlet of the rail to close off each injector circuit. This will tell me if I have a bad injector, or when all 4 are installed if I'm getting adequate pressure from the high pressure fuel pump.
I went cylinder by cylinder until all 4 ball bearings were in place so zero fuel would be getting to any injector to leak off. Still only getting 8 bar of pressure when cranking. I think my estimate of needing 300 bar is wrong, some say only 150 bar but still I'm WAY off.
So is the pump bad and just visually not showing damage?
The return line was not sending any fuel back so I know it's not bleeding off pressure there.
Is the fuel metering valve in the HPFP causing it to not build pressure or maybe the overflow valve in the high pressure pump? The HPFP overflow valve is supposed to open when pressure from the aux pump exceeds 4.3 bar. The aux pump should be feeding 5 bar at all times. Maybe the lift pump can't keep up with the aux pump to feed the HPFP?
I'm considering removing the timing belt system to remove the high pressure pump for a full inspection. It would need replaced regardless but at least could confirm the pump is the smoking gun before spending any more money. I just hate the idea of taking it apart then waiting for parts to install. That sucks.
Going to pull the HPFP head off again to clean some check valves. There have been some posts saying that possible blockage can cause it to not build pressure. This means I wouldn't have to pull the pump and should have an answer relatively quick.
Making progress! Sounds like it isn't the injectors. Or at least they aren't causing the low pressure issue.
In reply to jfryjfry :
Agreed. I think I've ruled out everything before the HPFP and seems like everything after it at this point. Hopefully some trash in the valves are the smoking gun. Super easy to rectify and then on to the fun stuff.
Awesome!!! Looks like you got yourself a great daily!
Yes!
dirty hpfp check valves???
Sorry to leave this hanging. I'm really not 100 percent certain what was the final fix.
I pulled the HPFP apart along with the check valves. I didn't see any material or obstruction but cleaned it out none the less.
Pump still looks to be in excellent shape!
So I started the process of bleeding for a bit, cranked for a sec and no pressure change was seen, still didn't go higher than 8 bar.
I decided to pull the ball bearings and clean out each line. There was a piece of metal in the valve of injector 1 (furthest to the left) which was alarming. Didn't see this before, and it started to get me worried. So I vacuumed out each injector where the line attaches as well as where the line attaches to the rail.
I had seen it mentioned when bleeding the lines to do it at the rail and not the injector. That's not what I've been doing. Also they said to start at the pump connection first, then to the first injector, then work my way to the end of the rail one at a time. I haven't been doing that, at least not systematically. This time I also would leave the nut loose until I saw bubbles stop, then quickly crank it back down while the pump was still pulsing. The settings in OBD Eleven just have a pulse, not a constant or fixed run time option. It seemed like if the pump was finished priming it would suck air back into the line if I didn't tighten it while still under pressure. Anyway after priming the pumps a bunch to bleed the system I turned the key. HOLY CRAP! It started!!!! The live data feed skyrocketed from the 8 to 300 bar, so I saw it go fast. It was awesome.
Was it the aux pump being weak?
Was it cleaning out the HPFP?
Was it properly bleeding the rail?
I'm going to say it's the rail bleeding. Which is annoying to think but I'm just glad I didn't dump a ton of money into fuel system parts that didn't need replaced. I spend around $130 on the two parts I purchased and maybe $60 on the injector tools. So I'm in the car ~$2700? I'm happy with that. I've learned way more about diesel fuel systems than I ever expected which was neat.
After my victory dance, I reinstalled the v-band clamp on the DPF and o2 sensor for a little joy ride. I drove it around a loop of my neighborhood and it drove excellent. No lights on the dash other than the rear driver tail light. More on that later. I was so fricking pleased. I could shut it off and it would immediately start. Even this morning it cranked to life with a blip of the key. Super stoked to have that happen.
HOWEVER I still have work to do. The flywheel sounds terrible, so the trans needs to come out. I can't order the new flywheel until I can confirm if it's a 6 or 8 bolt. My last A3 had the opposite of what I ordered so I'll mess with the timing belt stuff while I wait on it. Trans may be out Sunday if I have time?
Sweet victory!!! Gotta love when a problem isn't the actual expensive one.
Today I'll probably start ordering the timing components and maybe find some parts to repair the rear driver brake light. I had this same issue on my previous a3, just on the passenger side. I'm not sure what causes it other than friction or voltage increase when a bulb starts to let go, but one terminal gets so hot at the connector it melts the connector body. This then allows the pins to no longer get good connection and will cause intermittent light failure. Right now I get nothing. I kinda sorta tried to clean the pins and squeeze the female end to get a better connection but no go. Also someone caked everything in dielectric grease which I don't think is helping at all.
So this sub assembly attaches to the tail lense.
Which connects to the harness.
Everything looks great right? No blown bulbs.
UNTIL you unlock the carnage.
Hell. Yes.
Decided to do a quick and dirty temp repair for the driver side tail light. I had read it's common for the ground circuit on these to cause the burning of the connectors. Someone mentioned soldering a wire to the connection from the inside and a separate connector on the outside as a good fix so I decided to try it out. It works great!
After that was wrapped up I took it out for a quick spin. Other than the chatter in park from the flywheel it's acting exactly like it should. The audio on this car is the Concert with 10 speaker Bose and it's fantastic! I have an aux cable option for now but will add a Dension bluetooth piggyback.
Tomorrow I'm going to clean up the garage and start the process of pulling the transmission. With the trans out I'll finally know which flywheel to order. A timing kit has been ordered along with a water pump and serpentine belt. Still need to order a full oil and trans fluid service kit.
In reply to captainawesome :
F30 BMW 3 series suffer from the exact same tail light problem. Its a ground issue supposedly, and people add a ground like you did.
Now to the point of my post, lol, FCP Euro sells a repair kit with a new plug and contacts etc. Heads up in case you end up needed that, check FCP.
In reply to Slippery :
Yup, they have the same style part available for this one as well. I bought a new pigtail but the tail light assembly is around $80. I'm on a tight budget for now, so when I free up extra money I'll order the assembly for the permanent fix.
Yesterday was tool and workspace clean up. I also wanted to get a good wash on the car before pulling the transmission. The blue looks SOOOOOO GOOOOOD when clean. The interior is mostly done besides trying to treat some stains in the carpet. It all cleaned up really well. These pics were taken in really harsh noon sunlight but super happy with the outcome. Wheels are on the list though. They look okay in pics but in person are pretty rough. Also they just aren't my style. Still deciding on what direction I'll go and since these tires are practically brand new I'll drive on them for a while before I decide.
Nice work!
In reply to AxeHealey :
Thanks! Kinda frustrating I need to take it apart now but when finished it should be a good daily for the next few years.
That blue is one of my favorite colors. Think my wife's Cayenne is basically the same color
In reply to docwyte :
I think this one is Deep Sea Blue Pearl but need to confirm with the paint code. In person it is stunning, at least when it's clean.
Looks great!!
The color looks just like my '87 GTI 16V, love it.
I haven't pulled the trans yet. My Jeep's a/c compressor locked up over the weekend and parts to replace will be here Thursday. If I start pulling the Audi apart that means I can't pull into the shade to do the compressor so it can wait a couple more days.
And speaking of a/c, the reason the previous owner took the car into the shop was because it wasn't blowing cold air. I decided while I'm twiddling thumbs waiting on timing parts I could start the process of figuring out what the issue is. From what I can tell it's not low on refrigerant. The fans work. The compressor clutch isn't engaging when either the a/c button is pressed or through the OBD Eleven prompt. Still need to see if it's getting power to the clutch.
While tinkering with the a/c I could see quite a bit of smoke coming from the valve cover where the injectors bolt in place. Guess it's officially time to order the injector seals I said I would eventually get to.
The flywheel and injector seals have been ordered. I confirmed only the diesel engines had the 6 bolt flywheel and Autohaus AZ had a massive price drop on the one I needed. Like over $100 less than any other retailer. SCORE!
Timing components and water pump have arrived so I will get those installed this weekend. I may still pull the transmission out but don't really want the car to have to be in pieces for a week while I wait, so maybe it can wait until the day before to pull it.
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