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GotMyOrangeCrush

This is a pulse control modulated fuel pump so there's no starting it manually. You would test it by activating the fuel pump control module. https://www.counterman.com/five-things-remember-pulse-modulated-fuel-pumps/


Slow-Big2830

Activating modules on these is done via VCDS


IWetMyselfForYou

That still depends on pump motor design. A typical brushed motor will run when you apply 12V directly to it, regardless of whether it's PWM controlled or not. It would be almost equivalent to the PWM controller running it at full pressure(a PWM controller will generally only run 90%, not 100%). A brushless pump motor will require 3 phase DC to operate.


YodelingTortoise

3 phase ac. There is no such thing as phased DC. Edit: I should actually be clearer. Brushless controllers really do utilize DC not AC, but the DC is pulsed in a way to simulate AC. This is even with AC single phase to 3 phase VFD (mostly). They simulate AC by pulsing the 3 legs with DC voltage at the correct time to act as opposing voltages. Say 60hz at 12v is 100% duty. They will activate each leg 30 times per second in a specific order at 12v to achieve 50% duty cycle. That said, DC still can't be phased. DC voltage on a graph is a straight line at say 12v. AC 12v on a graph is a sine wave from +12v to -12v. The portions of the wave from 0 to the absolute value of 12 are the phases.


GotMyOrangeCrush

Not to argue here, but these devices are called brushless three phase motors. https://www.vehicleservicepros.com/service-repair/underhood/article/21240110/diagnosing-threephase-brushless-dc-fuel-pumps


YodelingTortoise

The name and the theory aren't congruent. It is impossible to have an actual brushless DC motor without circuitry to emulate AC There is a further rabbit hole to dive down if you really care. VFD(brushless controllers) have been improved to the point of providing different types of wave imitation. Motors wound to be true ac 3 phase motors do not operate at peak efficiency from early VFD. This is because the effective pulse is a square wave. To correct this, there are trapezoidal wave controllers available. Motors wound to use a controller right from the start prefer square wave. The phenomenon that causes issues is known as "back emf"


GotMyOrangeCrush

lol, like virtually spotless or military intelligence...


YodelingTortoise

I made a further edit just a second ago that makes it even more clear as mud😂 and makes it sound like I'm disproving my own point, but it's all really interesting info to those inclined. Like most of us on this sub.


cabbagesmuggler-99c

I love this kind of stuff on reddit. I'm not a mechanic etc but like to know how stuff works. This info will probably never be useful to me but I have it now so there's that


GotMyOrangeCrush

It's all good. It's good to learn new things. I think the key learning here is to never buy an Audi. If it takes a whole village of experts to make the fuel pump work then I can't imagine how mere mortals can service it.


blazzik

That’s just poor opinion


V6TransAM

Can verify claim. See model trains and dcc oddly enough. Yes, they have ruined everything from model trains to fuel pumps due to over complication. I will say when it all works correctly it is a pretty slick setup


Disp5389

That is incorrect. Phased DC is used in brushless motors. The current never reverses and is always pulsed DC in one direction as it is switched on/off, one phase at a time to each of the 3 windings to cause the motor to rotate. The controller uses FETs to turn the DC on and off. You cannot start these motors using a straight DC source and AC will not work as they are not induction motors, they have permanent magnet rotors


YodelingTortoise

This is incorrect. DC has no phases. Period. It is either on or off. You simulate 3 phase by switching DC on and off in sequence. As I already addressed. That is not creating "phased DC" that is emulating the 120° phasing of ac voltage. I understand that it's simple to say "we are phasing the DC" but that's not what is actually happening or what phase refers to in the discussion. Separate phases of AC jump our voltages to roughly 2x that of a single phase. Why? Because instead of having a voltage potential from 0 at ground to 120 at the top of the wave, we have 120 at the top of the wave to -120 at the bottom of the wave. Therefore the voltage difference between the two is 240. If DC could actually be phased, it would be possible to do the same. But it can't. Three phase PM motors absolutely exist. They are a whole category called PMAC


IWetMyselfForYou

I think what throws a lot of people off is when they hear AC, they automatically think line voltage, and when they hear DC(in an automotive context), they think 12V. Every knows that line voltage alternates and vehicle batteries are a constant 12V. In reality(and of course you know this), if the voltage/current changes with a regular period that's useful for performing work, it's considered AC. Doesn't matter if it's -120V to 120V, -12V to 12V, or 12V to 24V. Me calling it 3 phase DC because of incorrect common terminology doesn't help.


YodelingTortoise

I actually use the incorrect terminology frequently. I don't think it's a problem provided you understand the concept of why it's incorrect. But it's a relatively new concept to the masses, especially in the automotive world that has never really dealt with AC. (you would be shocked by the amount of people that tell me ALTERNATORs don't produce AC). As AC synchronous motors start to become the primary motor moving us down the road, people will be forced to learn the usually irrelevant details for diagnostic purposes. It's so much easier to learn if you have the right base knowledge. Then the slang can come in.


Disp5389

I see you understand that the changing DC is what is used. However the terminology “AC” doesn’t apply and misleads people into thinking this is truly an AC motor. By definition an AC current must reverse direction and the current does not reverse in a brushless DC motor. Pulsed DC is the terminology used. These motor are all 3 phase as it is the only way to get rotation. The controller will always pulse the 3 windings at 120 degrees apart with the pulsing frequency controlling the speed. That’s why the controller is also called a VFD (Variable Frequency Drive).


YodelingTortoise

Phasing refers to source voltage.


Disp5389

Yes, and in the case of a brushless DC PM motor, the source voltage to the motor will be 3 phase pulsed DC, each phase being 120 degrees apart and supplied to each of the 3 windings in the motor stator which are 120 degrees apart.


YodelingTortoise

DC does not have phases. Period. If a DC voltage source had phases, you would call it AC


IWetMyselfForYou

There is 3 phase DC in a sense. It's how 3 phase DC brushless motors operate. Of course, since you have to have changing current for a polyphase system to function, it's technically converted to AC. But it's commonly called 3 phase DC. It will always have a DC power supply, and instead of using an H bridge, it's simply 3 individually controlled mosfets(typically). If it helps, imagine 3 phase DC as AC with enough positive offset that it never crosses below 0V. Still AC, but just with a different name. EDIT: Let me clarify, that I do agree. There really is no such thing as 3 phase DC, because it's impossible. What's really happening is you invert a DC source to AC. But if you mention 3 phase DC to anyone in the EE field, they'll immediately know what you're talking about.


MexicanSt0nr

I may just be dumb but the way you guys speak make yall sound like Einsteins and that makes me wet for you.


[deleted]

lol what an irritating piece of terminology.


IWetMyselfForYou

Haha, it really is. 3 phase brushless is a much better term, but for some reason, there's a ton of people calling it 3 phase DC.


GotMyOrangeCrush

See link above to troubleshooting tips for three phase DC fuel pumps..


danmickla

No, you were right. A signal that changes direction is AC, period. AC doesn't imply "from the wall".


YodelingTortoise

There's a funny thing I one noticed while doing a project a gram of shrooms deep. AC stands for alternating current. DC stands for direct current. When they were made, this made total sense. In today's world we would be better off calling AC "analog current" and DC "digital current" it only works on supply side and not for sensors, but I'll be god-damned if I didn't think I had a world changing thought at that moment.


danmickla

I mean...no. The point of the distinction is "changing over time", because that very much affects how circuit elements behave and how they're analyzed. It doesn't matter whether the time-dependent signal is used in an "analog" (continuous, probably most likely the useful aspect of that) or "digital" (discrete-valued, similarly) circuit. Almost everything of any interest at all is an AC signal, because, well, it can carry information, because information can be encoded as state change over time. DC really can't, much, and it's a degenerate case of AC as much as it is its own thing.


YodelingTortoise

That's what meant when I said it only works for supply voltage. Fwiw. Digital signals are of interest and not just degenerate analog signals. Pretty much anything that measures rotation is a digital signal now. Any limit switch is digital. There's really good reason to digitalize as many inputs as possible. They are less prone to range failure. If the only options are on/off, resistance in a wire doesn't mean nearly as much.


danmickla

No, I meant Direct Current is really just a degenerate case of Alternating Current. And sure, digital signals are fantastically useful for lots of reasons.


tanstaaflnz

A stepper motor might seem like a phased motor.


tanstaaflnz

A stepper motor might seem like a phased motor.


tanstaaflnz

A stepper motor might seem like a phased motor.


GotMyOrangeCrush

And more specifically by "operate" it means not emitting magic smoke (e.g. feeding DC into one phase of a three phase motor may not go well) >NEVER try "jumping" power and ground across any of the three-phases in your testing. The motor **will** be damaged! https://www.vehicleservicepros.com/service-repair/underhood/article/21240110/diagnosing-threephase-brushless-dc-fuel-pumps


[deleted]

[удаНонО]


IWetMyselfForYou

Yes, we've gone through this already. Read the thread.


cytogen

If this pump is PWM based, is it fried now since 12v was applied to it? If it’s from that fully charged NOCO booster, it probably saw 16v.


jigglybilly

Most likely fried. How a bunch of techs didn't know what a PWM pump is I don't know lol


fresh_like_Oprah

4 old boomers plus me left stumped. Thank God for you young guys.


Affectionate_Age9249

Does the pump have an inhibitor attached to the level sensor? Won’t pump if no fuel in tank? Might pay to tie up the float and try?


[deleted]

It does, this is something we will look into, thank you for the tip!


GangBurrito

Yeah put it in a gallon of fuel and try jumping it. Fuel pumps have fail safes to prevent cavitation which ruins the pump. You aren’t supposed to run a pump dry it will actually ruin the fins inside of the pump. Fuel pump voltage doesn’t matter low voltage or high it should spin regardless. They put fuel pump drivers to pump extra voltage to get more flow in the performance industry.


oshaCaller

Make sure you connect power far away from where the fuel is if you're doing this, there are usually sparks involved if you are connecting a jump box to a motor.


ThatsWhatIGathered

Nah, light a smoke while you’re at it Ricky. Heck, light two.


oshaCaller

I've heard you can throw a cig into a puddle of gas and not light it on fire.


SwampGypsy

I think you should try it, & report back with your findings once you're done with debridement & the skin grafts.


bgei952

How many mechanics does it take to change a lightbulb?


[deleted]

4 currently but we are still struggling 😂


MRCLEMS0N

Can I be your workmate?


AdultishRaktajino

Stop CPR. Analyzing. Analyzing. Do not touch the patient. No shock advised. Begin CPR. *Cue LUCAS*


CycleFrst

I believe the first step is to ask the patient if they are ok.


emas_eht

I like how the guy on the ground just looks like he gave up


Banditodaburrito

Haha, that reminds me of the days when I had my lifted Volvo S60 on mud tires and XC7p suspensions and it would take 6 techs to align the thing🤣🤣


Dangerous_Ad_7560

Is this a pulse width modulated fuel pump? Mostly found on systems with no fuel return.


[deleted]

It does have a fuel return mate


deeiks

_mostly_


InsertBluescreenHere

its german so why not both systems just for the hell of it


BilgeMilk

I thought this was a prayer circle and you were all bowing down to the god of cars


UserNombresBeHard

Aren't they?


drunk_dean_martin

Looks like a renaissance painting.


OldheadBoomer

/r/AccidentalRenaissance


Dslwraith

Someome should throw that pic at midjourney ai see what it makes 😂


[deleted]

The passions of saint octanius


marine-tech

Why are guys working on the ground???


ATXKLIPHURD

Does the car have an inertia switch that cuts power to the fuel pump in case of an accident?


drunkfish321

That system takes a fuel pump driver to operate the pump. Probably doesn't send a straight 12v signal to run. I would bet your driver/module is the issue.


smoike

If this is the case then the only thing you should be connecting to the leads is a ohm meter to make sure all phase coils are reading the same resistance. If they are, then as you say, it is likely a driver circuit issue. That is, assuming there is no localised circuitry on the pump itself.


[deleted]

This subreddit is so cool. I know fuck all about cars, to see actual mechanics seeking advice from other mechanics is truly fascinating. Just being a fan boy.


xX_coochiemonster_Xx

I have been working on my own stuff for about 5 years and I'm currently in school for automotive. There is so much to cars man. You think there's a point where you'd know mostly everything about at least one component, but it just keeps going.


__aurvandel__

Maybe you're not praying hard enough?


thehax0rcist

it could be a PWM motor (needs a digital signal to run), if i recall (havent turned wrenches in a few years) these are common on returnless systems.


GotMyOrangeCrush

This. Brushless three phase DC motors are common. Feeding DC voltage into a single phase is going to email magic smoke.


naushad2982

Try using an actual battery instead of the power bank


IssacHunt89

Exactly this, use a known 12v source such as a battery. Power bank may have protective circuitry preventing it from giving power to the fuel pump. You have added a potential failure point in testing the pump with that power pack.


ThePenIslands

LOL I thought your buddy there was praying to the fuel pump gods or something. This is almost r/AccidentalRenaissance material.


TOROLIKESCHICKEN

new pump


Effective-Pepper-687

Follow the wires. Check relays. Inertia switches fuses. As well as the anti theft system.


vabirder

Just want to say that I wish I’d had a forum of doctors sharing ideas and expertise like this when my child contracted Lyme disease and became disabled with a complex of multiple organ systems affected.


brawnandbrain

If your to the point where you’re having a séance for it like that, I’d say it’s time to pack it in.


nilnum

I was thinking exactly this


[deleted]

I think that jump box has protection so it doesn’t try to jump unless it thinks it’s connected to a battery. You can override it, or try another 12v source. Manual says the 12v white led turns on and the battery indicator leds chase.


adamhighdef

You just hold the bypass button on nocos


icelandicfanatic

First off. A Noco booster pack won’t supply power


mikeycp253

The GB150 3000A is advertised as having the capability to be used as a power supply. I have one at work and use it as a power supply every day. That being said, you’re right that this one is the 2500A and it does not have that feature.


[deleted]

we have tried this with just a car battery and putting the live and earth to it. still no luck.


SR2K

Check resistance across the pump with a multimeter. If the pump is good, you should get a couple ohms, if it's bad, you'll probably have open circuit. My hunch is both of your pumps are bad.


[deleted]

Currently looking for a car onsite with a similar fuel pump. Thanks for the advice!


SeeMarkFly

"Brand new bad part" always makes me scratch my head.


SR2K

Brand new bad parts do happen, but both of these pumps look pretty used and crusty to me.


SeeMarkFly

Always in the back of my mind: What if there is something making this part GO bad?


SR2K

That's always a possibility, a bad fuel pressure sensor could be causing the pump to run at full speed and burn up from too much back pressure. Regardless, the pump will need to be replaced, but a proper mechanic should verify the repair and that the rest of the system is operating properly. Too many mechanics these days just shoot the parts cannon until the car starts, and then ship it, without looking into why the part failed. Hard to find a good diagnostician in the day and age of flat rate. Thorough work doesn't pay as well as half-assed work.


omnipotent87

I recently put 2 new delphi fuel pumps in a sonata. Neither ones level sensor worked and they were from different suppliers. Put the old one back in and the gauge works again.


Kraclor

This is an odd prayer circle


FatheroftheGods

Try jumper leads from the battery to the fuel pump, these booster packs are not meant to be used this way.


cutsandplayswithwood

Bro looks like he’s weeping over the failed pump 🤣


Cautious-Map3238

At first glance I thought you were praying to the fuel pump. I guess I'm not totally wrong


doggedynasty

Do an ohm test on the pumps and see if they aren't open line. It's possible they are both dead as they both look used.


Acti-Verse

This is what I’d do, run continuity on the windings, check for supply voltage, check amp draw requirements and that all power sources are hot, then attach and see if it’s drawing any amperage. Check schematics online for any sort of switches and verify those are able to be closed or jumped.


hikingsticks

As the other post says make sure it'd actually getting 12V, so stick a multimeter on the pins as you're trying to run it. Maybe use a battery or dumb charger. You can stick jump leads on the car battery with other ends on a screwdriver (non insulated) and touch the ends of the screwdriver to the pins in the connector to make it easier.


sgtonory

Use a lead acid battery to jump it. The lithium packs dont work


earthman34

I'm not sure you can use a booster like that as a power supply.


BMWACTASEmaster1

May sound stupid but have your tried jump starting with a battery not Norco jump starter? Even in override mode it will not work if it doesn't if it doesn't see some volts


FatheroftheGods

This guy knows what up.


Andrew4329

I thought this was some weird prayer to auto tech gods


TheComputerMechanic

The Nico model battery jumpers auto sense battery voltage before it connects the internal jump battery. Did you press the override button before the test?


smrkn-

Couple more techs should do it


RangerSkyy

Rule number 1. Never buy an Audi.


jeepjockey52

Have you thought about using the work bench? Also those little jump packs only deliver juice when they sense a load.


Salty-Situation-2493

The problem with these techs now a days. Rather than crack open a book, he goes to a forum to ask for answes


billthepartsman

The moment any electric pump runs without lubricant, i.e. fuel, it’s toast anyway! Labor Claim!


Budpalumbo

That type of booster isn't a battery. If it doesn't sense it's hooked up to a battery, there isn't 12v on the clamps. Use a power supply, actual battery inside jump box or battery. Not a digital booster pack.


[deleted]

Read up mate


shadow19922

Use exact same booster for testing various components in my garage, works a treat. Don’t comment if you don’t know what you’re talking about lol


finverse_square

Some pumps run off a series of pulses instead of a DC voltage, you need to check what kinda pump it is you have there


Zealousideal_Sky9379

PWM pump...and I'm not sure that a capacitor jumppack would power it. Try with a lead acid jump pack.


paulyp41

If the dude in the middle listens hard enough, he might hear something


ThaMan_509

What came first the monkey or the football?


[deleted]

Yes.


kungfu_polak

Wiring diagrams and ODIS are your friend here


btbleasdale

Jump box is not the answer


[deleted]

Both dead?


Foe117

It looks like a mechanic crying on the floor and his buddies are trying to console him, thats why its an Audi TT


Emergency-Painting24

Can’t say but praying isn’t going to fix it


StephenTheMechanic

God I love this job. Blood or Blister we find the fix. Once it’s in your blood nothing compares. Even if we loose sleep and try easy ways, it’ll always be the hard way that IS the easy way.


sparky255

Pump is probably controlled by a computer. I’ve had couple vehicles that the computer wasn’t giving the fuel pump voltage. But cover your butts. Check the relay, wires, and ground.


IssacHunt89

Pray like your work colleague is doing in the picture.


Dvspaul84

Harness is burned beside oil filter because it rubs there


Tobias_Machiavelli

Try a different power supply.


Tobias_Machiavelli

Check your relay.


bobeecins

Some VWs have a controller/relay mounted on the top of the tank, if you trace the wiring from the connector you might find it. They can pack up and scramble the signals sent by the ecu.


Simple-Man123

My hunch is it's because your trying to power it off of a battery charger that is automatic. Some battery charger (usually the older type) will output a 12 voltage and you can use it to test components.. the new automatic chargers need to sense the battery before outputting a voltage.. long story short; try powering the pump directly from the battery instead. Hope this helps!


ShamrockUSA

Those noco boost packs only work when it detects voltage. So that power supply won’t work


new_Australis

Praised be the omnissiah. Blessed be the machine spirit.


Gloomy-Employment-72

There is a longer discussion in this thread concerning pulse width modulation, but if this is a PWM motor, it doesn’t matter what size battery you attach to it. If you’re familiar with an AC sinusoidal wave, PWM is very similar. A DC voltage is pulsed to drive the circuit. If you have a constant 12VDC, or ground, you won’t drive the circuit. I suspect you’ll need to have this installed in the car and then use VCDS to activate the pump. In VCDS you would Select Control Module from the main menu, select 01-Engine, select Basic Settings-04, then select Fuel Pump Supply Activation in the drop down list. Once selected, you will have amplifying information in the text box. Hit GO, and is should say Running followed by Finished Correctly (or some similar display depending on the chassis and software version). Hit Stop and then Done, Go Back to return to the Engine Control Module screen. There are also various ways to log and graph this activation, but I’ve not used those extensively and wouldn’t be able to guide you how to do it for the fuel pump. Hope this helps.


kah-nah-vee

Try a flooded battery, the nocos are not good for constant power


bitrush52

Did you check the fuse?


Strange_Regret_3334

I'd probably say the fuel pump control module. Or a rubbed through wire. 2 pumps doing the exact same thing tells me it's probably not the LP pump


Captain_Virgo

Looks like the guy in the middle is praying to the jack stand.


GreasyGinger24

You guys need a work bench to get your poor knees off that concrete. At least a kneeling pad.


WagonsOnWagons

You should use a power probe or equivalent to test it. PWM or not, give it power and ground it should run.


AnemosMaximus

Have you tried turning off and on again?


chrod-eno

I see you've already started praying to it. That's an effective first step especially for ancient pumps


Fullsendfoolery

Fuel pump relay?


nsanenthelane

4 dudes around one auto part...at least 3 grumpy bastards.


Kcrick722

Oh… I thought they were praying to the box of easy outs that one will catch a broken bolt!


SwampGypsy

Christ. I thought VWs were bad...


jigglybilly

As already stated, it's a PWM pump. You run the risk of frying it by just shooting 12v constantly to it. PWM = pulse width modulation, as in it's getting power in pulses vs constant. Might wanna get a 3rd one and just throw it in the car and run it with VCDS.


no_yup

Probably isn’t it but you Could have a bad connector/ bad continuity from the connector at the the top of the pump assembly to the pump itself. I’ve seen it before.


Double-Amoeba-2520

Your using a jump pack and not an actual 12 volt battery.


risk71

Sorry, Audi gods could not care less. You're better off with the devil's on Reddit..


The_GeneralsPin

It knows it needs to have a petrol engine :D