Wont start after fuel pump install

[texasboy21]

Installed new fuel pump (OEM with DW300 pump) and the car will not start. I cannot hear the pump prime. Am I missing a step? No codes.

[Jet08]

Logically this would suggest a defective pump, but likely the control module. Have you a 12V source then test the pump but disconnect all other wiring.

[nick1980]

Just replaced a fuel pump on an a8 where it sits in a "cup" and gravity feeds itself fuel.
If not seated right or very low fuel it wouldn't start.
Did all this work and still wouldn't start,checked fuses relays etc
Replaced fuel filter ,back in business

[EvolutionArmory]

Pull it out and check the work. I know your fuel pump came preassembled but who did the assembly?

Check the wiring for your aftermarket controller before you do that though. Maybe you disconnected something by mistake. You could always just plug your old factory fuel pump controller in first if you still have it and see if it will prime. That would eliminate the pump as the cause if it works.

[texasboy21]

Pull it out and check the work. I know your fuel pump came preassembled but who did the assembly?

Check the wiring for your aftermarket controller before you do that though. Maybe you disconnected something by mistake. You could always just plug your old factory fuel pump controller in first if you still have it and see if it will prime. That would eliminate the pump as the cause if it works.

Your friends at JHM did the assembly.

I plan on going over all of the items touched yesterday. I will start by plugging in the old pump and see what happens. That should let me know whether its the car/electronics (a friend suggested I replace the fuel pump relay), or the new pump.

[EvolutionArmory]

Your friends at JHM did the assembly.

I plan on going over all of the items touched yesterday. I will start by plugging in the old pump and see what happens. That should let me know whether its the car/electronics (a friend suggested I replace the fuel pump relay), or the new pump.

Probably done by the same guy who adjusted my wastegate or pressure tested my replacement intercooler tube.

I wouldn’t let their shop change my windshield wipers now.

[EvolutionArmory]

Logic states that the new pump is what changed so that’s the probable cause but you never know with how modded your car is from stock.

Good luck. It sucks that you can’t just buy something from a so called reputable source and have it just work right away from the start. 🤣🤣🤣

Hopefully I’m wrong and I’ll have to eat my words but my track record with them is on my side 😉

[vce1232000]

Probably done by the same guy who adjusted my wastegate or pressure tested my replacement intercooler tube.

I wouldn’t let their shop change my windshield wipers now.

..............

[texasboy21]

It sucks that you can’t just buy something from a so called reputable source and have it just work right away from the start. 🤣🤣🤣

I think you can.. Audi of America just dont mess with it! I hear the RS3 is nice, too bad its not a manual..

[EvolutionArmory]

Having owned a DSG car (it was only a TDI though), I’d gladly trade my manual A4 for a RS3 😀

The only thing I didn’t like was paying for the fluid and filter every 40K.

[vce1232000]

I think you can.. Audi of America just dont mess with it! I hear the RS3 is nice, too bad its not a manual..

shifting is over rated. Automatic's shift faster now

[texasboy21]

So I am sure at this point I have a dead or dying battery. VagCom says 10v, windows slowly crept up, and the radio is acting funny.

I can hear the faintest whine from the pump with the key in the ON position, but there doenst seem to be enough to turn it over.

The Boost Manager devise running directly to the fuel pump is indicating that it (the BM+) is powered on and normal.

[EvolutionArmory]

Lol!!

Looks like I may be eating all those words from earlier.

[texasboy21]

I have pulled my battery and have it charging. Hopefully its as simply as that.

[dalmation53]

Well atleast we can confirm is not my broken fuel pump

Sent from my G3313 using Audizine mobile app

[texasboy21]

Fully charged battery installed and it started right up. After a few minutes of idling as I picked I shut it off and tired to restart - no go. Tried again after inspecting stuff and finding nothing and it started up.

Perhaps its just 'new pump' behavior? Im going to grab vagcom and go for a spin.

[EvolutionArmory]

It should work the same every time you start it. 😀

So far you’re 50/50. That ain’t good. Are you getting a no crank no start or just a no start? Do you hear the pump prime every time now?

[texasboy21]

The couple of stalls might be a fluke (or due to the cracked PCV breather hose.. add that to the list of repairs.).

I have taken a couple of logs, see below. 280g/s and no dips in fuel pressure. I will need to take some additional logs as the car feels a little slugglish.

[texasboy21]

The car sat over night and just fired right up as normal. The pump seems to be working as it should.

Over night the battery voltage per vagcom was 12.1v. Does that sound about right?

Now on to more fueling logs! I need to determine what is causing my P310b codes (2) - both at idle.

[EvolutionArmory]

+12v cold, +14v running and +10v cranking is what I would consider a good battery.

[texasboy21]

+12v cold, +14v running and +10v cranking is what I would consider a good battery.

Awesome, I think I can call the install complete.

I hope it worked.

[EvolutionArmory]

Well you know from your logs that you don’t have low fuel pressure. You’re meeting or exceeding HP and LP. CoUld it be leftover codes from the no starts of your old pump or the issues you had with the new pump yesterday?

Could it just be from all the aftermarket stuff you’re running?

[texasboy21]

Well you know from your logs that you don’t have low fuel pressure. You’re meeting or exceeding HP and LP. CoUld it be leftover codes from the no starts of your old pump or the issues you had with the new pump yesterday?

Could it just be from all the aftermarket stuff you’re running?

Honestly, I think it is from the banjo bolt on the hpfp. It's damp and it reeks of fuel within a one foot radius of the pump. It smells dangerous.

[Jake@JHM]

Let me know if I can be of any help.

[vvenom800tt]

Just curious, are you tuned for the bigger pump or will the ecu compensate enough to not flood?

Sent from my SM-G960U using Audizine mobile app

[EvolutionArmory]

Just curious, are you tuned for the bigger pump or will the ecu compensate enough to not flood?

Sent from my SM-G960U using Audizine mobile app

I think he can also edit his fuel map from the controller set up he is running.

I’d be interested in seeing the lambda logs.

[texasboy21]

Correct, I have semi control over the stock A4 controller. I can run the full OEM program, the OEM program until a set point I determine and then my own mapping, or fully from scratch mapping.

Right now I am running a tweaked version of the Eurodyne BM+ base map for the 2.0T with a stock controller and uprated pump.

[vvenom800tt]

Ok gotcha.

Sent from my SM-G960U using Audizine mobile app

[EvolutionArmory]

Honestly, I think it is from the banjo bolt on the hpfp. It's damp and it reeks of fuel within a one foot radius of the pump. It smells dangerous.

The post you quoted was meant to say you don’t have a fuel pressure problem. You’re meeting or exceeding fuel pressure requested for most of the log.

If you got a leak there you should take care of that though 😉

[vvenom800tt]

The post you quoted was meant to say you don’t have a fuel pressure problem. You’re meeting or exceeding fuel pressure requested for most of the log.

If you got a leak there you should take care of that though

Thats why i converted from banjo to barb fitting. Fuck that bolt.

Sent from my SM-G960U using Audizine mobile app

[Charles.waite]

The low pressure side should regulate itself so there’s not really any need to modify the tune, I’m pretty sure. The injectors are run off the high pressure side so the low pressure side is just a “dumb” supply, more or less.

You can’t really have too much fuel on the low end, but you can definitely have too little.

[texasboy21]

The low pressure side should regulate itself so there’s not really any need to modify the tune, I’m pretty sure. The injectors are run off the high pressure side so the low pressure side is just a “dumb” supply, more or less.

You can’t really have too much fuel on the low end, but you can definitely have too little.

By modify the tune I mean modify the LPFP controller mapping.

I am still getting high pressure codes at idle. P310b.

[Charles.waite]

Ohh yea sorry I misunderstood.

[Theiceman]

I would consider 12v low. I would expect 12.6 . Just keep an eye on it.

[Charles.waite]

I’d agree. The battery should be upper 12s resting voltage.

[EvolutionArmory]

That’s why I said +12 😀

If VCDS told him voltage was 12.1, I wonder how accurate that is compared to actual voltage at the terminals.

[Charles.waite]

Well it depends I suppose at what component you’re reading the voltage at. If there are shorts or draws between the battery and a specific component you might see differing voltages being reported.

If everything is healthy I would expect the voltage readings in VCDS would be quite accurate.

[EvolutionArmory]

Well it depends I suppose at what component you’re reading the voltage at. If there are shorts or draws between the battery and a specific component you might see differing voltages being reported.

If everything is healthy I would expect the voltage readings in VCDS would be quite accurate.

That’s what I was saying. Whatever is telling him what the voltage is currently is also drawing voltage to operate.

Doesn’t matter as it seems his car is running now.

Looks like he is chasing a boost leak or wastegate setting issue now from PM’s we’ve had. He’s not reaching full boost until like 5k. And he has a huge dip in high pressure and a huge spike after it.

What do you guys know about the 3 wastegate packs these turbos can run. Could he have the low boost pack installed and need a higher one? Here’s the EFR training manual if anyone is interested in reading it. Wastegate info starts at page 25. The manual says that the default wastegate canister is medium which is for 12-18 PSI and there is a high boost canister for 20-30 PSI. Maybe he needs the high boost canister or maybe he just needs to adjust the rod on his default medium canister.

http://www.turbos.borgwarner.com/fil...ical_brief.pdf

[ZooomZoom_Yames]

Theres slide plugs on the pump. Sometimes they slip off. The cars runs terrible then wont start anymore if that happens. Or it may not start. I would check that

Sent from my SM-G950U using Audizine mobile app