Can a clogged fuel filter cause a no start issue?

[ChuckNasty149]

Hey everyone,

I’ve had a hard time starting this beast the last couple of weeks, and it has gotten progressively worse to a point the car won’t start anymore. I’ve got a 17072/P0688/001672 - ECM Power Relay Load Circuit: (J271): Open Circuit code, and multiple misfire codes from all cylinders. When I could get it to start after a minute of going at it, it would shake, sputter, then the cel would flash, then it would idle back down, and run fine the rest of the day. One day I was wiggling a coil back and forth to make sure it was down all the way, and the car just shut off, and I blew fuse #29. Replaced that and it hasn’t blown since. All fuses in the side panel look good. My coil harness looks terrible and I can see exposed wire, so I ordered a new harness from ECS, coils, crank position sensor, and the 127 ecm relay. I haven’t ordered a new fuel filter yet because I need to figure out if my car has 4 prongs on the filter or 2, and it’s been too nasty of weather to work on this car right now. Ill check fuel pressure at the rail and spark when I get all the parts in, but has anyone else had symptoms like this? Couldn’t find in any previous post if the fuel filter could cause this. Ive been running the tank pretty low switching from E85 and 93, so I'm thinking that might have caused the filter to clog up. Thanks for reading, I really appreciate any help.

Charlie

[duk3]

I've had my b6 stutter for 2 days and then refuse to turn over. Changing the fuel filter was remarkably easy and an instant fix. Good luck!

Idk anything about that trouble code.

[MacFady]

Just call the dealer with your VIN and get the part number for the right fuel filter, or go to Europaparts.com, they have real time chat at the bottom right, you can get them to check the right filter for your VIN. Or you can always stick your head under the rear passenger door and look yourself. Might as well take 10 minutes and change it anyway.

[hightime80]

Correct me if I m wrong but pretty sure all the 1.8t's have the 4 pronged fuel filter since it also serves as a FPR.

[imnuts]

Correct me if I m wrong but pretty sure all the 1.8t's have the 4 pronged fuel filter since it also serves as a FPR.

The 1.8T is either 3 or 4 port I believe. The split is between 03 and 04, just like the 3.0.

Sent from my DROID Turbo 2

[old guy]

2003 has a four port fuel filter.

[imnuts]

Looks like the split is between 04 and 05 at some point after looking it up.

Sent from my DROID Turbo 2

[B6A4Dave]

2003 has a four port fuel filter.

^^ This. Usually Variant J.

[ChuckNasty149]

Thanks for the info everyone! I'll probably just see if my dealer has the filter tomorrow, since I'm itching to drive this thing again. I'll post what my findings are after work. Cheers!

[ChuckNasty149]

Update: changed the coil harness, fuel filter, and the engine management fuse and still no start. No fuel or pressure at the fuel rail, and it fires right up with starting fluid. I'm guessing I can rule out anything electrical? Going to replace the fuel pump and hope for the best

[Furly]

Fuel pump.

Did it have acceleration issues before it died completely?
It's an easy swap and you can buy the oem manufacturer one for much less.

[ChuckNasty149]

Well I changed out the fuel pump with a new walbro and still no start. I have lots of pressure coming out of the farthest rear fuel line on the cap, fuel sprayed everywhere. I'm going to have a buddy come over tomorrow with a fuel pressure gauge, but I still see no fuel or pressure at the test port on the rail. Starts right up with starting fluid. Still can connect to the ecu and I cleared the codes and put it on its stock tune. I've replaced the following with no luck...

Coil harness
Coils
Crank position sensor
219 relay
Fuel filter
Fuel pump

Any suggestions to stay away from the dealership would be swell. Thanks guys

[ChuckNasty149]

I also didn't have any acceleration issues previous to this as well, just a hard start issue

[old guy]

Unplug your MAF sensor and see what happens when you try to start it.

[ChuckNasty149]

Just unplugged the maf and no luck old guy. I think the car just hates me.

[SlickFix]

2003 has a four port fuel filter.

My early 2003 Avant has a two port fuel filter. Just an FYI that you really need to check before ordering.

[ChuckNasty149]

Ya it's the 4 port for sure. The old filter wasnt clogged up that bad either.

[imnuts]

My early 2003 Avant has a two port fuel filter. Just an FYI that you really need to check before ordering.

That only came on the 02-03 3.0 models, as the fuel pressure regulator is on the fuel rail and not in the filter. The 04+ 3.0's have a 4 port filter I believe, as they moved the FPR off of the fuel rail.

[Let it snow]

Well I changed out the fuel pump with a new walbro and still no start. I have lots of pressure coming out of the farthest rear fuel line on the cap, fuel sprayed everywhere. I'm going to have a buddy come over tomorrow with a fuel pressure gauge, but I still see no fuel or pressure at the test port on the rail. Starts right up with starting fluid. Still can connect to the ecu and I cleared the codes and put it on its stock tune. I've replaced the following with no luck...

Coil harness
Coils
Crank position sensor
219 relay
Fuel filter
Fuel pump

Any suggestions to stay away from the dealership would be swell. Thanks guys

You had fuel pressure at the pump and not at the rail? Is it possible the fuel pump/filter lines got hooked up incorrect?

[ChuckNasty149]

The two pump lines are where they need to be, I may have hooked up the filter wrong. Any way of knowing what lines go where? The clips were colored differently, and that's why I feel like i didn't mess up on that.

[ChuckNasty149]

Filter has the word motor stamped on it facing forward so I believe the direction is correct. The lines are resting well, not kinked or stretched over one another.

[diagnosticator]

Well I changed out the fuel pump with a new walbro and still no start. I have lots of pressure coming out of the farthest rear fuel line on the cap, fuel sprayed everywhere. I'm going to have a buddy come over tomorrow with a fuel pressure gauge, but I still see no fuel or pressure at the test port on the rail. Starts right up with starting fluid. Still can connect to the ecu and I cleared the codes and put it on its stock tune. I've replaced the following with no luck...

Coil harness
Coils
Crank position sensor
219 relay
Fuel filter
Fuel pump

Any suggestions to stay away from the dealership would be swell. Thanks guys

STOP using starting fluid! It has no practical merit and should not be used. The risk of serious engine damage is very high using starting fluid. If the engine has compression, fuel and ignition spark, it must start up. Starting fluid does not help resolving the issue. A no start will either be the wrong air/fuel ratio for a cold start, or there is no ignition spark.

Audi service instructions direct to bleed air from the fuel system before attempting starting the engine after replacing the fuel filter and other fuel system compenents. To bleed the air from the system, remove the schrader valve from the fuel rail pressure test port using a tire stem tool. Next cover the port at the end of the fuel rail with a large rag. Next, cycle the ignition key on for 5 seconds then off and repeat until fuel flows out of the fuel rail test port. Replace the test port schrader valve and start the engine if there is spark occurring.

Also be sure the engine is not fuel flooded. This can happen after a lot of starting attempts when something is preventing the engine from starting normally. Pull a spark plug and check the tip for wet gas fouling of the plugs. A flooded engine does not fail to start from wet plugs, the air/fuel ratio is to rich for ignition to occur. IF the engine is flooded, press the accelerator pedal to the floor and crank the engine in 10 second ON, 20 seconds OFF intervals until the engine starts up.

Bleed the fuel system first.

[diagnosticator]

The two pump lines are where they need to be, I may have hooked up the filter wrong. Any way of knowing what lines go where? The clips were colored differently, and that's why I feel like i didn't mess up on that.

I think you would need to make an effort to connect the fuel lines on the filter wrong providing the filter is installed correctly for direction front/back.

[old guy]

The two pump lines are where they need to be, I may have hooked up the filter wrong. Any way of knowing what lines go where? The clips were colored differently, and that's why I feel like i didn't mess up on that.

On the front side of the filter the skinny hose goes in the center port. On the back side the hose with the blue clip goes in the center port.

[ChuckNasty149]

Update: Had the blue clip in the rear of the filter hooked up wrong to the top prong. Switched the two around, bled the fuel system like the diagnosticator had said to do, saw fuel coming out finally, started right up and idled perfectly. Thank you all so much for your help, I can't tell you guys enough how much I appreciate the input. Since I swapped out so many parts I thought it could be, I can't really say for sure what caused this issue.

[diagnosticator]

Update: Had the blue clip in the rear of the filter hooked up wrong to the top prong. Switched the two around, bled the fuel system like the diagnosticator had said to do, saw fuel coming out finally, started right up and idled perfectly. Thank you all so much for your help, I can't tell you guys enough how much I appreciate the input. Since I swapped out so many parts I thought it could be, I can't really say for sure what caused this issue.

Good job! Thanks for the update.

BTW, be sure to clear all the fault codes. The ECU power supply relay DTC that was occurring before, is most likely fixed now. I think that was the main problem.