How did I kill my 044 in less than 2k miles?
 

So I just finished replacing my 044 that died a few of days ago. I had just finished the fuel pump wiring mod and made it a couple blocks from home when it blew the front pump fuse and started running like crap. It immediately blew the spare fuse I swapped in as well. Limped it home and figured I must have messed up some wiring, but after quadruple checking my work I couldnt find any faults.

Luckily I ordered my 044 through Amazon and they warranty all automotive items for 1 year so after a short live chat I had a new one on the way. They told me the used unit was now hazardous material and couldn't be shipped back to them so I could keep it. Big props to Amazon customer service.

I just finished swapping in the replacement pump and it works like a charm. What I'm trying to figure out is what caused it to go in the first place? Maybe debris in the fuel tank? I didnt drain the tank the first time so I went ahead and did that this time. There was a little debris in the bucket I drained out of the tank, but the screen came out clean with no debris. Could that kill the pump that fast? Defective pump?

Also, I bench tested the one I removed and it seems to spin, but I dont have the setup to determine if it is flowing properly.

if it wasn't mfg'd in Czech Republic, it's a Chinese knockoff known for early failure

Yeah I read up on all of that before I bought it and figured Amazon is a pretty good bet for genuine items. It was made in czech republic and shows no signs of being counterfeit.

Also I should note that there is a screen in the inlet on the pump and there is absolutely no debris on it...

FWIW, the pump you got to keep would probably work fine with EFI. EFI runs at less than half the fuel pressure 930 CIS needs and the fuel pump draws much less current and has an easy life because of it.

You're lucky you didn't have to return it. I've always had to return them to where I bought when they were too noisy and I did.

You might want to check your system pressure after you installed the 044. I had to lower my system pressure back to a normal range after I installed my 044. The pressure went sky high thus putting a lot of strain on the 044 pump. Seems okay now after I re-shimmed the regulator.

That's a good idea. I havent checked pressures, but my afrs are unchanged so it couldnt have changed too much. I'm leaning towards it just being a defective pump.

If your car is an '86 and it has the original aluminum lambda fuel head in stock or modified form your system pressure is around 98 psi. It should be anyway, because the lambda fuel heads are designed to run at higher system pressure than the older cast iron fuel heads that ran at around 86psi.
You can raise and lower system pressure and adjust the spring tension in the upper chamber differential pressure valves to work around that for more top end fuel delivery.
My car has a CIS Flowtech modified fuel head with the lambda system removed and upper chamber fuel meterng orifices enlarged. When I removed the stock fuel pumps and replaced both of them with Bosch 044 pumps made in Czech Republic there was no change in system pressure. It remained at 98psi.

Yeah mine has the original fuel head with the lambda system removed. I replaced the pump because it was leaning out above 5500 regardless of adjustments to the WUR. The pump solved the problem so I think the stock pump couldn't maintain the fuel pressure at the higher volume needed at high rpm. I looked into raising the system pressure, but since my AFRs are correct now, I dont see the need. It is my understanding that the pump shouldn't affect the fuel pressure since that is controlled at the regulator, but rather allows for a higher volume of flow when needed.

Exactly... the regulator controls pressure by returning fuel to the tank,
..and just like modern ball bearing turbochargers with billet compressor wheels, pressure and volume are two different things.

It is my understanding that the pump shouldn't affect the fuel pressure since that is controlled at the regulator, but rather allows for a higher volume of flow when needed.[/QUOTE]

Anytime you change anything in the CIS fuel system, a gauge-check should be performed, regardless of what it did before, opinions or otherwise. And if all checks out, then good. If not, you can go from there and make the necessary adjustments. Do not "assume" that your system pressure is correct just because your AFR's are the same.

digging this one up from last summer

one of my 2 new made in Czech Republic 044's is acting up nearly exactly a year to the day from purchase, and maybe 2-3k mi (?)

WTF?

and I'd confirmed with all the known 'tells' (packaging, etc.) that these were genuine not knock offs

making loud 'dry' noise now, and car won't take any throttle w/o running like CRAP

oddly enough, the next day the pump was back to sounding normal and the car drove great

tried it again today, back to loud and crappy

just ordered another one via Amazon, and will return this one - so hopefully just annoying and no $ lost

but yeah, friggin annoying tho - guess it's better the rear vs. the front from a PITA to swap perspective, but it's not like the rear one is a particular treat to swap either

and guess I should be happy it didn't outright fail, and this is all "local" and not on a roadtrip - but makes me now worry about the front pump - grrrrrrrrr

QUESTION: I thought I'd read here these cars would run on only ONE 044? Why does the car run like crap w/ 2 pumps but one acting up?

curious

most annoying tho is the timing of the failure - this literally happened like 12hrs after (finally!!!) fixing my horn, and 1/2 way fixing my sunroof - as is always the case w/ this car... fix 2 things, break another... argh!

I've been through around 5 of these f....... donkey piss pumps... genuine ones yeah.
Rear 044 is quiet and smooth and front one makes a lot of buzzing noise. Directly wired to battery with relays and individual blade fuses.
I don't know and I gave up on them a year ago. I just live with the buzzing front pump now and hope it keeps working.
I guess they're made for EFI and not the high pressure needs of aluminum CIS fuel heads and my front one is going to always buzz.

oy

I don't mind audible buzz, this sounds dry and strained and is affecting the delivery

grrrrr

I found a while back that when one of the pump's relay was bad, the other pump would cavitate and sound dry. Maybe they can run on only one pump but if one is dead, it's restricting the flow. However their design should be pretty free flowing but that little bit of resistance could be enough.

I don't know... at least you have a new one coming for free.
Have you made sure the rubber fuel line isn't pinched where it crosses over the steering rack? If you have steering rack bump steer spacers installed there's a chance of that.
Is the metal fuel return line inside the gas tank flowing freely? It's skinny and for some reason some people have had it clog up inside the gas tank.

Paul, trying to push through the second will strain the pump even further than it is under normal working conditions.

Correct, because these are close tolerance roller pumps. Kind of like a roller bearing and if the rear pump stops the front one will have an extremely hard time trying to push fuel around stationary rollers in the race they run in.

Peel a dead one apart sometime so you can see how they work.

thanks, and yes I plan to just out of queriousity

:eek:

"thanks, and yes I plan to just out of queriousity"

Yeah I peeled a part a dead bosch one from an L jetronic BMW 7 series years ago out of curiosity.
The two curved magnets inside them are strong and make killer refrigerator magnets.

My replacement pump makes noise periodically, mostly when the tank is getting low. Not sure why, but it doesnt seem to effect its operation.

I'm currently on only one 044 pump. No other fuel pump being used. I've been curious about this as a problem with my AFR though. But I never run out of fuel as far as I can tell. My problem is idle and cruise richness. My cruise highway AFR is leaner. I plan to rectify this with my BL WUR once other unrelated issues are worked out.

You know you're a gearhead when the magnets on your fridge are from a fuel pump. :)

-Jeff Foxworthy

I've always had a soft buzzing from my front pump since I've had the car (10 years), however I drove it yesterday, it ran fine with no differences until I made my final journey of the day of about 3 miles to put the car away.

The front pump was really loud as soon as I started it up, the revs were a bit up and down 700-950 for a minute of so before settling at 850, but the buzzing was replaced with more like a loud grinding (I could hear it over the engine noise as I was driving along) from the front pump area for the whole 3 miles despite the car driving well and pulling hard?

Two questions -

Does that mean it's terminal for the front pump?

If so, I've been reading Waynes book (101) about changing the pump, do I really need to drain the fuel tank or can I just clamp off the hoses?? I have half a tank of fuel so it would be a bit of a problem. Or is it worth draining the tank and checking that out for debris etc??

Thanks in advance!

I just swapped mine out 2 nights ago with 1/2 tank as well, it's not too bad a job.

I went w/ dual 044's... if you go this route, ensure you receive a legitimate Made in Czech example, there are a ton of knockoff "Made in Germany" examples out there which are proven junk unfortunately (use of these does require 2 fitting adapters - 1 for front output, 1 for rear inlet... I got mine from Chris Carroll @ TurboKraft).

jack nose of car up as far as you possibly can w/o the tailpipe hitting the ground - use jackstands, and have a fire extinguisher and plenty of rags on hand just in case... and ensure you're in a well ventilated workspace as the fumes suck bauls

something like this provides for decent work room under there - anything less (BTDT prior time) proves annoying and frustrating being crammed:

<img src="https://lh3.googleusercontent.com/aWodfnY1K0tOJrgSYq_rpLPdgPqhzIYu8yKG9uXwbAZc=w1597-h898-no"height=600width=1000>

then:

• remove the skid plate - 2 large hex bolts secure the rear and are shared by the sway bar brackets (the bar exerts some force upon the treads - somewhat upon removal, but moreso on reinstall), and 2 17mm (IIRC) nuts on the front
  
• clamp the feed line w/ vicegrips or other method - I used 3 pair and it was barely enough, still allowed for an annoying trickle which filled maybe 3" of a bucket - (*note: the feed line may WELL BE brittle and puncture when doing this - if you have the ability to drain the tank, now's a great time to replace that short section of rubber hose... be sure to have one on hand - my closest FLAPS did not have that ID hose in stock, I had to try a few)
  
• loosen the pump bracket w/ a screwdriver
  
• remove ground connection on bottom (8mm on my 044), being sure to catch the tiny washer (*note: be careful to not pull the loop connector off of the wire - the wires are EXACT length and do not afford much if any room to maneuver them unfortunately... BTDT, had to add a wire extension)
  
• remove fuel line on passenger side of pump (17mm/19mm on my 044), again - catch washer / be careful of connector
  
• remove power connection on top (10mm on my 044)
  
• remove feed line w/ a screwdriver
  
• swap pumps
  
• install is reverse of removal 8-)

my only caveat is to *be careful when manipulating the pump trying to get the output line off*... (this being the 2nd time I've swapped pumps up there proved to be more than the OE feed line which runs thru the tunnel was willing to accept and it sprung a massive pinhole leak just under the swage fitting... game over)

good luck, HTH...

Thanks Paul.

I've ordered up a replacement front pump. Do you think it's worth changing the rear one out too?? It doesn't make a sound when running unlike the front one which has always made the buzzing noise from day one!

If the rear pump isn't making a lot of noise there's no reason to replace it. If the motor is stock or close to it there's no reason to remove the original ones to install 044 pumps either.
The original made in Germany Bosch fuel pumps are much higher quality than the current day "genuine" 044 pumps.

My car is completely original except the sports exhaust. I haven't gone for 044, I ordered a genuine parts one from Porsche today.....i'm now £492.00 (£410.00 + vat) lighter!! :(

I wasn't suggesting to go 044, Jim - was only referencing my application

but after reading ^the price paid^ (!!!)...

...I'd 100% have gone 044.

Crykie!

I have been having trouble with my 044 pumps too. First I installed an 044 up front and had trouble with burnt fusible links. I rewired the fuse to run off the a/c feed at the fuse box. Then the front pump failed after about 1 year. I replaced it then the rear pump failed. I installed 044 at the rear and front then the front pump failed again after3 months. Now the front pump is noisy but has not failed, yet. I decided to drain the tank and check the fuel hose and piping. I realized the fuel did not flow easily, unless the filler cap was loose. So there seems to be problem with the venting system. The 044 pulls a lot more than the standard pump so if there is a problem with the venting system, could there will be extra strain on the pump.
Has anyone looked into this? I found a few collapsed and old vent lines I replaced them yesterday. No time yet to test.

As a side note. The Bosch-Siemens Coorp. is big in Europe, I was recently informed that Bosch has moved its Czech appliance factory back to Germany. Maybe this will also influence their pump division?

Interesting - can you share photos / details of which vent lines you found? Would love to check mine as well.

Bummer about all your failures - hopefully (well, you know what I mean) those are due to them being knockoffs and not a larger issue.

Can't say I'm at all in the mood to touch another FP on my car after doing both of them 2x in a year... nope.

That sounds like the best news I've heard in a while.
Women from Czech Republic are incredibly beautiful but their fuel pumps are screamers.

I just got told by Porsche that the pump would be coming from Germany, which may be true but I doubt it was made there, as labour costs are very high compared to Czech Republic or Poland or any euro countries on the eastern side.

....so are the women ;) :D

Above cannot be stressed enough...

I wonder if Denso makes a capable pump? Never had one fail over the years. Some custom work required, no doubt.

So I changed out the pump at the weekend and can confirm it's still made in Czech Republic as it's stamped on the casing.
The change over was fairly simple and mu previous fear about not being able to hold back the tide of fuel trying to escape was totally unfounded. A couple of decent hose clamps and no problems.
While it's not yet re-connected I plan to flush the tank and change out the fuel filter.

Am I correct in understanding that the fuel filter is accessible from the large hex bolt seated in the underside of the fuel tank??

Thanks

This might be a useful reference

Bosch Australia, Fuel pump test results by part number ( interesting note is the 044 tests at the same flow as my 984)

http://apps.bosch.com...../Fuelpumpflowrates.PDF

Also from Bosch Motorsport with delivery/pressure curves

http://www.bosch..../Fuel_Pump_FP_200_Datasheet.pdf
the standard FP200 is rated at 5bar and is the normal 044 part #
they also list an 8bar unit with a motorsport part #

Well its even noisier now. I cleared the evap system and loosened the front subframe to check the hoses were not crimped in anyway. Put it all back together and its quiet for about the first 10-15 minutes then gets gradually noisier. No running issues and the fuses and relay are not particularly hot. I will try swapping front to back pumps and see whats what. I just dont want to be stuck.

I think I sorted it. I remove the pump and found the upper, rubber mount was broken and the positive terminal was loose. So i swapped in another brand new pump, but following my mechanics advise I pre-filled it with oil. Started it and, its just a tiny bit noisier than OEM. I drove about 40 miles yesterday with no issues. BTW some of the the pump clamp teeth were damaged which prohibited further looseness allowing it to touch the pan. Also the 044 is larger than OEM so some spacers on the pan nuts will aid with clearance. Now to see if the sell will take the noisy pump back.