I recently changed my setup to a 255 intank and a inline 044. After driving the car for a little bit the 044 all suddengets really loud, then 5 min later it's quiet again. This will happen numerous times while I'm driving the pump will go from quiet to really loud in a split second. But yeaterday I drove the car all day and it was quiet the whole time. The pump was brand new when I bought it and the fuel pressure is constant and a/f is not effected when the pump decides to be loud. Any input is appreciated

 

Almost sounds like its cavitating, might want to just check the pickup on the in tank pump just in case..

 

Mine does that sometime, but I don't see it affecting anything. I have a 255 in-tank and the 044 mounted against the firewall with rubber mounts to absorb some of the vibration.

 

044 cavitation usually sounds like dropping a couple pebbles in a running blender

Check your inlet filter (the filter before the pump, should be 25 micron), make sure it's not clogged

If you have a filter larger than 25 micron before the pump, check the inlet screen in the pump itself (take the inlet fitting out of the pump, you should see a clean white nylon screen in there). If it's dirty - you need a better/finer inlet filter.

 

You sure it's a real 044 Bosch pump and not the cheap ripoff?

 

Your right. sounds like gravel. Its basically the pump running away from the fuel. Make sure you find the issue.

 

Im using the stock fuel filter and I guess i could replace it. Im almost positive the pump is real, ive looked at the threads comparing the real to the fake and it looks to be real. My buddy with the exact same setup had the exact same thing happen with his pump. It also would start becoming really loud at random times.

 

What I'm about to type certainly isn't going to clear anything up, just sharing a relevant experience.

A couple years ago I had a customer buy & install a 044 pump from us. He reported back that after he drove the car around for a while, the pump would start making noise.

Everything in the fuel system was new, nothing was clogged or dirty. We thought maybe the return fuel was getting so hot, it was heating up the fuel in the tank, and due to the increased fuel temp., cavitating the pump. Customer re-routed feed & return lines away from the exhaust (and turbo), and it took longer for the pump to make noise, but it still made noise.

I had the customer verify that the 'pick-up' filter in the tank was not bottomed out and had plenty of area to draw fuel from. All OK.

Then we tried a piece of rubber on the pump mount to reduce vibrations. Everything checked out OK, but we couldn't identify or get rid of the intermittent noise problem.

Customer sent the pump back to us. Submerged on our flow bench at 13.2 volts, the pump functioned perfectly and without any abnormal noise. Sent the pump back to the customer, submerged in the car, noise. The pump functioned 100% in the car, no loss of fuel pressure, but we both knew it shouldn't be making the noises it was. Since neither of us could identify what the problem actually was, the customer eventually went to twin 255's.

Having sold hundred's of 044's over the years, this particular case still bugs me. I bring it up because maybe you have another mystery noise making pump????

 

I've had 044 pumps make odd noises in the past that I could never resolve, yet i've never seen them cause an issue. Same type of deal as discussed here. Since they've all worked fine regardless of the small change in sound, I never worried much about it.

 

I appreciate the response and im actually using the install kit bought from you. Im just concerned and dont wanna beat on the car while the pump is loud. It really is 100% random, paticular driving, amount of driving, or temps dont effect when it happens. Just really dont wanna know the hard way that the pump isnt working properly when its making the loud noise...

 

I was about to post the same thing as Tony. But. Do you have a fuel pressure gauge in-car? Do you have a wideband in-car?

 

I dont know about you guys but Ive seen Bosch electronics in general do some strange things over the years things...

 

Wideband yes, fuel pressure guage no, its on the rail so Im clueless while driving

 

Do a test while the car is running. Im thinking you already have an aftermarket AFPR correct? Try and set the base fuel pressure too 55psi, and see if the problem persists. If it goes away, problem was the bosch 044 is sucking in more fuel at lower base pressure then the walbro 255 can provide at that given pressure. Which is kind of hard to believe myself b/c at around 43psi the walbro and bosch 044 flow almost identical, but the odd thing to that is when the flow testing was performed it was never mentioned what kind of fuel was being used in the testing. If it dosent, try and get the car to idle at the higher base fuel pressure, and pay really close attention to the fuel pressure guage. Connect the vac source back to the afpr and see what the guage is doing. If your having cavitation issues, the car WILL NOT be able to hold a steady base fuel pressure. The fuel pressure will be jumping a good 2-4psi, and the Bosch 044 (only) will be making a intermittent hissing noise approx. every 6 or so seconds, this is the formation of air-bubbles in the lines (cavitation), the AFPR will not be able to provide a steady base fuel pressure b/c of this. Also just for good measure do you have any kind of kinks or bends within 12" of the inlet of the bosch 044? I have a walbro intank and bosch 044 mounted in the engine bay, about 12" away from the fuel-rail, I ran into this very same issue and my problem was a slight 45* bend coming from the fuel line to the inlet of the bosch, once I deleted that my problem was solved.

 

Yeh there is actually almost a 180deg bend off the stock fuel filter for the 044 inlet. This is the kit im using from t1, you can see the fitting at the bottom right of this picture that goes ontop of the fuel filter.

 

i wouldn't think any of the provided fittings would cause an issue. thousands of others use them with no issues. i'd say you're going to just have to deal with it, and that more likely than not, (if nothing is clogged, etc.) that its just some random noisy pump. if you really are bothered, switch a pump with a buddy. but i don't think you really have that much of an issue. if it was working improperly, you'd see it in the tune or while driving. i know how little things like this bother ya tho.

 

Sometimes mine will change pitch or sound slightly when I am cruising around and I have the same setup, 255 intank to 044 inline.

Never noticed any issue, a/f is steady and fuel pressure from what I can watch (underhood gauge) at idle or holding a constant increased rpm holds steady.

Its not like a gravel sound or grinding noise, its like a slight pitch change in the sound of the pump from low to higher and back. Pump is being fed consistant power from a 30A (maybe 40A I forget which) relay setup and all that good stuff. Rubber isolated mounts holding it to the firewall. I have a full flow elbow fitting just like you pictured above but push lock aeroquip stuff. Dont know why it does it but seems to no affect anything.

 

Is this a voltage issue, like when the alternator starts charging? I have seen on OBD2 cars ( converted to chipped OBD1) where the voltage drops at idle to as low as 12.5volts and then around 1500-2000 RPM kick back up to 13.5-14V steady.

I have this setup as well, waiting for engine to be installed to test out the 044.

 

Im not sure if its the voltage doing it because ive been stuck in traffic idleing and its been loud, ive also been cruising on the highway and its loud

 

I've been thinking about this way too much but I'd be really interested to see what the inlet pressure on the 044 builds to and if that has negative long term effects.

What I'm thinking is: a decent 255 at 0 psi will flow about 520 lb/hr.
The 044 at 50 psi flows about 450 - 470 lb/hr.
So, we have 50 to 70 lb/hr of excess building on the inlet of the 044 (which dimishes as the pressure builds).
If the 255 builds pressure till it's dead-headed (which it will because there is no relief), it could be putting XX psi on the inlet of the 044 which was never intended to have pressure there.

And the higher one sets the base pressure, the worse this scenario becomes.

Could this be the culprit? Has anyone ever put a pressure gauge between the 255 and the 044? Is that pressure pushing the armarature in the 044 into a bad position? Or blowing some seal in there? I think I know what I'm doing at work tomorrow.

 

Here is a tidbit of what I know about pumps and cavitation in general....

If you have two pumps in one header you need to have them offset by a certain amount. I say this because if you have them running in parallel in the same line (either suction or discharge) it will cavitate. You need to run a lead and a follow. It's the way fluid dynamics and pumps work. Same flow/rpm/pressure builds harmonics in the liquid which in turn causes the pump to build air pockets around the impeller. The air pockets bursting is cavitation.

I doubt that is what's going on since you are running them in series....

What's the load of the engine when you hear it most? Is maybe the 255 supplying too much pressure or flow at lower loads causing issues for the 044?

 

Scott, I'm not sure if I told you or not, my twin walbros made a bunch of noise as well???? Who knows?? Maybe it's just the design of the tank??

This year I'm having a cell and external anyways, so no worries there anymore.

I hope all is well.

 

I havent even got the car tuned with my new setup yet. Ive been driving around on last years tune just to make sure everything is ok for dyno day. So no i havent even floored the car yet and its making noises whenever it feels like it

 

When mine changes pitch the a/f is not affected. I am getting good voltage according to my turbo timer which is between 14.3-14.5. I haven't noticed anything in the way the car drives, it just changes sound every now and then.

 

Voltage at your timer will be different from the voltage at the pump unless you pull your power from the same source....

OP: What AWG wire do you have feeding your 044?