How probable my fuel filter or fuel pump?

[Seerlah]

Went to start my car this morning and it stumbled upon starting. Didn't think too much of it. Gave it some throttle before engaging the clutch, and it stumbled again. Still didn't think too much of it. Reverse out my driveway, give it some more gas to get rolling in first, and it stumbles again. Ok, that was one too many times. Pull the car back in the driveway and take the Maxima to work. Get home to diagnose and I start with the gauges I have on my car. Well, my fuel pressure is way low. Initial thought is my AFPR is shot, so I swap back in my OEM 4 bar fpr. Same readings. At this point I jump on FCP and order a Bosch fuel filter, which should hopefully arrive by the weekend.

But my question is, how probable is it that it is the fuel filter and not the fuel pump? I have a Bosch 044, and they are loud. Does not sound like the speed of it diminished, plus that thing should be able to flow way more than the ~43psi for idle (granted same numbers with my OEM 4 bar fpr and AFPR set at 58psi). Car drove perfectly fine when I drove home last night. Then today...poop. And I had my fuel filter changed roughly 35k ago.

[Corrado_Guy]

Usually the filters don't all of a sudden restrict flow unless something bad got into the fuel/tank. Have you checked the wiring to the pump (if it is not an in-tank or if the wiring is modified) and tried jumping the relay to make sure they are both good? Do you run the tank near empty a lot causing the pump to suck air which can kill them in no time?

[Seerlah]

I have an in-tank setup. I also found it weird for it to all of a sudden happen, which is why I asked. I usually fill up around the 1/4 tank mark. I am also pondering the thought of maybe my fuel feed line in the tank having a rupture in it, but it was perfectly fine last night. And I just thought about it, but boosting yesterday I noticed like surging when holding 20psi. Thought it had something to do with my bov, wg, or turbo. But now I am thinking it was a fueling issue. The pump I can clearly hear working and whining loud, as all 044s do. That is also on my mind.

Could this pump possibly just not be flowing how it used to? Also, what is the best way to get the tank down to 1/4 full if sitting at half a tank? And would you happen to know the amount of fuel that is? Want to get what I need before this weekend to get it sorted out. But I don't want to purchase a new pump unless it is deemed that is def the issue. They are not cheap.

And on another note, I was looking in my Bentley manual and Audi for some odd reason believes their fuel filters last the lifetime of the vehicle. Who do they have on their engineering staff that believes that stuff? Just as bad as the magical tranny fluid that never needs to be changed.

[revolution337]

In the engineers eyes, "lifetime fluid" probably means "lifetime of the warranty". After that, they could care less.

[M-Hood]

Did you do a flow test Mitch? Pull the line off at the fuel rail and see how much fuel you get in a set time running the pump, then pull the line at the fuel tank cap putting a rubber line on it to a can and run the pump for the same amount of time to see how much fuel you get from there. If you get more fuel at the tank then you get at the rail then the fuel filter is most likely clogged and causing a flow restriction.

Could this pump possibly just not be flowing how it used to? Also, what is the best way to get the tank down to 1/4 full if sitting at half a tank? And would you happen to know the amount of fuel that is? Want to get what I need before this weekend to get it sorted out. But I don't want to purchase a new pump unless it is deemed that is def the issue. They are not cheap.

To drain the tank you just use the pump itself. Just disconnect the line from the rail if you have a aftermarket rail or at the spot were the hard line connects to the rubber hose. Connect a hose to that spot and down to a fuel can, pull the fuel pump fuse and jump that spot to one that has power all the time or just when the key is on. Run the pump enough to drain most of the fuel out or till it starts spitting out of the hose going into the fuel can.

[thenj3]

someone in the s4 section just had a 044 die in like no time. my guess leans to the ppump though mitch unfortunetly

[disturbed_audi]

wow you have had a ton of problems lately with your car.. hope you get it figured out..

[M-Hood]

someone in the s4 section just had a 044 die in like no time. my guess leans to the ppump though mitch unfortunetly

But usually when a pump dies it just stops running. I wonder if that S4 owner had an actual real 044 or a cheap version from China.

[DWP]

I have a BNIB 044 up in the classifieds. Just sayin'

[Seerlah]

Seen it. Not quite sure if you know, but you can get them cheaper searching with the actual Bosch part number 61944 or 0580254044. Dmaxn let me borrow his Walbro 255 anyways. Picked it up today. Just need to let some fuel out the tank and install. It does not have a sock filter though. Hopefully my stock one fits. About to check this out in a couple minutes. Just got home.

[Seerlah]

PSA: Think I'm going to bite the bullet on this product. I don't plan on going anywhere for a while (you will see how it lasts). So if it works, then you guys will now have a cheap replacement for a high flowing pump if you wanted to get one versus dishing out extra dough on the Bosch units. I mean there are the Aeromotive ones and such, but they require direct power from the batery with larger gauge wiring and so forth. Looking for a plug and play solution (this pump with 034MS bracket for the stock basket might be it). Think I'm going to call these guys next week to see if they have a test flow chart I can see, and possibly post on here. But for now, I am def considering picking this up.

http://www.ebay.com/itm/230814803467...84.m1423.l2649
http://www.electricfuelpumps.com/index.html

[thenj3]

Did the other pump work?

[Seerlah]

Going to work on my car in a little bit and test it out. Just need to run to Autozone and pick up some more fuel hose, clamps, and butt connectors. The pump I received does not have everything I wanted to make it work, but I'll make it work. For example,no sleeve but I was told by the person who let me borrow it I can stuff some fuel line hose in the basket to make it fit snug. And it has no sock filter, but there is a screen on the inlet. I just don't like how large the gaps are on the mesh screen compared to an actual sock filter. But the fuel filter should take care of the rest. This is the only part I have. Fuel filter did not come in yet, nor extra relays (found a meal deal on ebay. picked up 3 for $12 shipped used OEM). Hopefully it is the pump, because that is what I will be working on today . If it is a different part then that means more work.

[Seerlah]

Fuel filter came in today. Went to Autozone to pick up parts I need for work on 2 cars tomorrow, and ordered some stuff from Auto Performance Engineering. Flex hose, sleeve, and sock filter. If the pump really is the issue, then these are parts I feel comfortable running the Walbro 255 pump with. But went to start the car at night when I got home, and it was rough. Took like 3-5 tries to make her start. And if I give it any throttle, car would cut off. And the pump I can still hear operating (clear prime noise). Since the fuel filter came in, I think I am going to just start with that. Start her over afterwards and see what my FP looks like. If that fixes it, then there you go. If not, then I will drain the tank to 1/4 full and go from there. But first I need to swap out the rear rotors/pads on my Maxima. Need the reliable vehicle actually reliable. Can't trust the Audi too much. haha

Oh yeah, slept most of the day basically recuperating from a long week of work. Put in 10.5 hrs alone yesterday, not even counting driving time to and from work. Anyways, was knocked out like a baby basically the whole day. But tomorrow I basically need to work on the cars. Rear brakes are a must. And the Audi...I miss driving her already. Only been a couple days.

[Seerlah]

Kind of convinced the fuel pump is shot. Went to start the car and pressure is now at 25psi. Slowly going down. Just going to wait till the parts for the Walbro 255 comes in and swap it in. If it fixes it, then that answers the question. Just drained the fuel to a little below 1/4 tank and parts should be here in the next couple of days. And to be honest, I'm getting pretty tired of this car. Want something different. But when I am actually driving it my whole attitude for it changes. Guess keep making little changes to reach 400whp and call it a day.

And for pics, by far the easiest way to drain the tank. Picked up 5ft of 5/16" fuel hose. Hooked it up to the hard line in the engine bay, took off the cover for the fuel pump replay, key in starting position, hold the relay closed, and watch the needle slowly drop.

[zandrew]

I am having the exact same issue except I have a stock fuel pump. Did you ever have issues with start up where it would crank for a about 30 seconds before finally starting? Does your car start and idle fine?

[M-Hood]

I am having the exact same issue except I have a stock fuel pump. Did you ever have issues with start up where it would crank for a about 30 seconds before finally starting? Does your car start and idle fine?

Have you checked to see if you have fuel pressure before you go to start the car?

[zandrew]

I have been jammed with work and have not had a chance to dig in it yet. I have the fuel pump just need the time. My dumb @$$ filled it up (93 octane) so I am in the situation where I need the fuel pump upgrade (going to a Bosch 042) and I plan on doing it. If that does not fix it then move on to other possible issues.

The car starts just fine and idles at consitent AFR but when I give it gas its weak and at WOT my AFR is in the 18s even when I approached 4K which I did once. It misfires like crazy but I have no codes though. It actually acts a lot like water in the gas but I have treated that issue so it could not possibly be it.

I am going to mount a fuel pressure guage on the firewall though.

Any good install articles? I am trying to make sure I have everything 100% before I start.

I apologize if I thread jacked you Seerlah.

[Corrado_Guy]

It really does sound like a pump, typically i test the pressure at the rail and then right at the output on the tank and check for any pressure gain/loss. If you are losing pressure check right on the top of the fuel tank and see if you get the same reading and if you do you either have a lot of crap in the tank that is blocking the pickup or the pump is gone.

[Seerlah]

Stock fuel line is 5/16". It is really as simple as getting an in-line 5/16" adapter and placing a fuel gauge in it. Cut the rubber fuel feed line and clamp it in.

http://focus.c-f-m.com/cfmperformanc...erfitting.aspx + gauge of choice

Also, my Autometer FP gauge crapped on me in like 2-3 days. Summit Racing one has been trucking it since then.

[zandrew]

Seerlah I am going to CNC one with 1/8 NPT ports so I can mount it on the false firewall. Its actually really simple and I want a way to mount it so its not flopping around. Some of those guages are filled with flammable liquids.

What all did it take for you to get the 044 to fit?

[Seerlah]

You can't get the 044 to fit in the stock basket without an adapter, and 034MS is the only company I know that makes it. There is a write up in the B5 S4 section using the stock basket of a different Audi chassis.

I did mine for cheap. Called shokan got a audi 100 v8 basket and strainer for $40 and then got my 044 from WorldPac then fittings off ebay.

Ko3s.. I bought the car stock after my last got stolen.

As for the snub I'll install it and see what happens thanks for the heads up.

Got the 044 from worldpac today

I personally picked up my setup used in the classified section for $300 shipped a couple years back. Been fine till ever since like a week ago. It was the 034 setup in the link below. Could very much be the same thing that DiscoPotato did, for all I know.

http://www.034motorsport.com/fuel-in...ons-p-384.html

Then here is the adapter to run the 044 with the stock basket. I so far know 3 people who used this and they all like it.

http://www.034motorsport.com/fuel-in...m-p-22897.html

Gumby (Matt) is running one.

one of the parts i was oddly excited about installing was this billet fuel pump adaptor. i thought it was an interesting design.



the adaptor slides over the fuel pump, and clamps down wherever you want to set the fuel pump height in the tank, while reusing the outer basket ring.

[Seerlah]

Ended up being a rip in the feed line in the tank. Easy fix. Snip off end and re-clamp. Bosch 044 still kicking strong.

[Believer]

Wow.. amazing how such a little thing can cause such a big pain in the ass.

[Corrado_Guy]

What's your guess? Was it properly installed or a defective hose? You don't want it to fail again because this is not a common failure area so you may want to replace the feed hose. Too bad you didn't look there first but it explains the decreasing amount of fuel pressure if it is ripping more and more as you are diagnosing.

[Seerlah]

Clamp was too tight. The rip started by the metal ring of where the clamp was seated. The lower clamp on the feed line used to be there. It is loose in the pic, just resting on the line as I fixed it (just snipped off that damaged part). Then slid the clamp back up and re-clamped.

[zandrew]

God I hope this is all my issue is but since all my components are stock, I doubt I will be nearly as lucky.

I am hoping to be able to tear into it on Sunday.

[walky_talky20]

That photo made me cringe a little bit.

The clamp was not too tight. Quit using those crappy hose clamps. You need EFI-rated clamps for an EFI application. Smooth ID, rolled edges, and preferably not worm-type. In fact, I prefer not to use those crappy parts-store clamps in *any* application whatsoever.

You wouldn't use a hose with a 9psi rating for your feed line, right? Likewise you must use clamps rated for the application as well.

The left one is good stuff. The right one is the reason this thread exists:



Yes, they cost 8 times as much. Yes, they are difficult to find locally in the size you need.

[walky_talky20]

Well, crap.

I went and did it again. Typed my way into coming across as a certifiable grade-A douchebag. My apologies to Mitch and community. The above post was uncalled for. I could have been much more tactful and considerate...but I wasn't and I'm sorry. I'm not going to edit it and hide from what I've done, but I will post what I should have posted here:

Mitch, I think you need to reconsider the type of clamps you are using there. Those cheap clamps tend to shred the hoses, causing the exact problem you ran into. I see it happen a lot. I would recommend using exclusively EFI-rated clamps for that application. They have a smooth ID, rolled edges, and are not worm-style, so they can clamp tighter and without damaging the hose.

Regards,
Walky

[Seerlah]

Local autozone has been out for a while. I know because I purchased their last ones months ago. They are being used on my engine bay fuel lines. And yes, they were too tight. They are not the proper clamps to use there. But that does not mean they can not be used.