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palauoriginal

Walboro Fuel pump whine..

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Hello all,

 

I recently did an l28et swap in my 1975 280z. It is stock aside from an msa downpipe, megasquirt, aeromotive fpr, and a walbro 255 fuel pump. I got everything running but my fuel pump is extremely loud and according to my fuel press. gauge it surges from 40 to 20 psi at idle once it heats up. When I drive it, (which i shouldn't) fuel pressure gets down to 0 until i let up and comes back to 40psi. Now this is on maybe 4 gal. of gas. 

 

See Vid:

https://youtu.be/papZzY5_VRY

 

I'm just wondering if I should get a new pump or if should reconfigure my fuel pump inlet from the tank. (maybe more gas!! :ph34r: )

 

Any feedback is appreciated. 

 

Thank you!

Edited by palauoriginal

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I'm just wondering if I should get a new pump or if should reconfigure my fuel pump inlet from the tank. (maybe more gas!! :ph34r: )

 

Probably both.  

 

Your fuel pump inlet is cavitating and the pump has destroyed itself as a result - once they start whining and losing pressure like that they don't get better..  Check to make sure that you have minimized any restrictions on the inlet, and also make sure that the tank is properly vented.  What kind of filter is that on the inlet (I'm assuming it's the inlet)?

 

As you mentioned, running on a low tank is also not a great idea - the less fuel you have the quicker the fuel temps rise (less thermal mass in the tank), and hot fuel cavitates much more easily.

Edited by TimZ

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thats not right, walbros do whine when they get loud but your fuel pressure dropping to zero means theres an obstruction on the inlet/outlet somewhere, or perhaps a voltage loss? need to do more diag

 

EDIT: I just watched your video. That clear prefilter is definetley causing it. You need a mesh screen type prefilter. No paper or brass. Try to minimize the fittings with bends and run the largest line you can to it.

Edited by 240zdan

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Thank you for the replies!  

 

It's a fram G3 filter. When I first got the pump, It seemed like others were using the fram G3 as a prefilter so I put it on.

 

Right now Im running a 1/2" hose from the tank to a 3/8" hose to the fram G3 filter to a -6an 180 deg. into the pump inlet. 

 

@jacky, I'm not familiar with fuel surge tanks and how to set them up so I . 

 

I just ordered another walbro pump and some -8an fittings for inlet to the pump. 

 

Any suggestions on a good prefilter to run? 

 

Thanks again!

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I had a similar situation, I was leaning out at high load and it was noisy as hell.  I ended up running a low pressure fuel pump to feed the walbro.  It got significantly quieter, no more fuel starvation and I even measured the current draw for both pumps and the total electrical load was lower than the walbro by itself.  

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I had a similar situation, I was leaning out at high load and it was noisy as hell.  I ended up running a low pressure fuel pump to feed the walbro.  It got significantly quieter, no more fuel starvation and I even measured the current draw for both pumps and the total electrical load was lower than the walbro by itself.  

 

Sounds like a good way to get fuel to the walbro.. Did you have the low pressure fuel pump part # or Maybe pics of the set up?

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Nissan used a big inlet hose to feed the pump with an open screen to keep out the big stuff.  If the tank is clean you shouldn't need that filter.  The pump will actually pass some pretty big crud and the big filter before the rail will clean it up, under pressure, before the injectors.  The inlet filter is over-"engineering", throwing the whole system out of balance.

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Carter 4594 works well as a lift pump to get the walbro the fuel flow it needs. I have one on my car feeding into a 4l surge tank, then a walbro picks fuel out of the surge tank. Its an extremely effective setup and I get no fuel starvation under high Gs even with an empty tank.

 

I agree with ditching the prefilter all together. Shouldn't need one in this scenario. You definetley want-8 inlet, and try to ditch any bends in the lines/fittings if you can.

Edited by 240zdan

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Nissan used a big inlet hose to feed the pump with an open screen to keep out the big stuff.  If the tank is clean you shouldn't need that filter.  The pump will actually pass some pretty big crud and the big filter before the rail will clean it up, under pressure, before the injectors.  The inlet filter is over-"engineering", throwing the whole system out of balance.

Sorry this is where you are wrong ZH. Nissan originally used a Roller Vane pump which are relatively insensitive to dirt particles. Roller vane pump will grind dirt up and spit them out.

 

 

A Walpro and similar modern pumps are Ceramic Turbine pumps with extremely fine tolerances and they will NOT tolerate any dirt or rust particles getting through. Pre-filters are necessary In fact, Airtex and other companies demand that the fuel tank be removed and the thoroughly cleaned  before installation of a new Fuel Pump or the lifetime warranty is null and void. 

 

Here is a Video from Airtex explaining the differences between Roller Van, Gerotor and Ceramic Vane pumps. And the Pro's and Cons of each:

 

Ceramic Vane Turbines are explained at 4:17. 

 

https://www.youtube.com/watch?v=QbzEeWy1b3o

 

Note that Ceramic Vane pumps are usually designed as an In-tank pump by most modern manufacturers. The in-tank pump cage usually contains a Pre-filter or sock that attaches to the bottom of the pump. 8:30 in Airtex video.

 

When used as an External inline pump you must have a pre-filter installed for CV pumps. Nissan did not use any pre-filter on the in tank fuel pipes, because they used an external Roller Vane pump and the Roller Vane pump will tolerate contaminated fuel. AirTex, Aeromotive, Mallory  and all electric fuel pump manufacturers recommend some form of pre-filter when using a Ceramic Turbine pump. Either in tank or external.

Edited by Chickenman

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I'm seeing gerotor design for the typical external Walbro 255.  Like an L6 oil pump.  They typically pass a lot of crud.

 

http://walbrofuelpumps.com/255lph-walbro-gss342-intank-fuel-pump.html

 

http://walbrofuelpumps.com/walbro-gsl-series-universal-inline-fuel-pumps

 

https://en.wikipedia.org/wiki/Gerotor

 

I think that Walbro has done some good marketing and is winning the image game.  but really, they're about the same as the other guys.  My tendency is to go with what the high end car makers use, for their long lifetime, high displacement, relatively high performance engines.  Like the Bosch pumps used on BMW's, or Ford F150's.  High flow, correct pressure, designed to last a long time.  Pretty sure they don't use a prefilter.  Just saying, don't overcomplicate.  

 

Never seen any demands from any fuel pump company about filters or cleaning tanks either.  Got a sample, maybe some instructions or a web page?  And Airtex is just your run of the mill aftermarket company.  Which Walbro is too, really.

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Airtex is the single largest manufacture of aftermarket fuel pumps in the USA they are not a small company. They also have a massive library of educational video's and articles for the Professional mechanic.

 

Gerotor pumps ( Walpro 255 ) are also much more susceptible to contaminants than Roller Vane pumps. Do some research.

 

You've never seen recommendations for cleaning a fuel tank before replacing a Fuel pump? You've got to be kidding. #1 failure point of replacement pumps is not cleaning the fuel tank. New fuel tanks are pristine inside. 10, 20 or 40 year old tanks aren't.

 

Do some more research. I'm not go to do it for you..... although I could, but I've got better things to do. Like work on my 280Z

 

Modern factory in tank electric pump do use a pre-filter. It is an absolute  necessity on Gerotor or Ceramic pumps. It can be as simple as a mesh screen or a " sock " on the bottom of the IN-Tank fuel pump. But they all have them. Exception being Roller Vane pumps as they are like garburators and will happily grind up just about anything in their path.  But Roller Vane pumps are noisy and inefficient at the higher fuel pressures that modern EFI systems operate at.  ( 3 to 5 Bar ) . They are good for pumping diesel fuels though, as Diesel fuels contain a lot more contaminants than Petrol.

 

Again... do some research. All the info is out there and is repeated over and over again via numerous companies. Quite asking others to do you homework. Airtex just happens to have one of the best Technical archives since they are one of the largest manufacturers of electric and mechanical fuel pumps in North America. You try and make it seem as if they are some small time company in HoBoken and their information is irrelevant. That's BS.

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Installation instructions from Bosch. Note references to cleaning COMPLETE fuel system including fuel tanks. And replacing all in tank strainers Direct link to Bosch .PDF.

 

 

https://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&ved=0ahUKEwi9zIPN5MvNAhUJxGMKHcTpBF4QFghXMAk&url=http%3A%2F%2Fwww.outlawspeed.com.au%2Fsendfile.php%2Fid%2F1bd79dc5646b0592221c3442af7d99df%2Fname%2FWheelBackSpace.pdf&usg=AFQjCNH_AYnAqkOrUSO1Ky8XLkr32xPNRw&sig2=fArAq4pvZUmZeUqgNTFgGA&cad=rja

 

 

 

 Important Information
Always follow the vehicle manufacturers fitting / replacement instructions. Before fitting a fuel pump the following checks should be undertaken.

• Ensure the entire fuel injection system is clean and free from contaminants.
• Ensure that the correct fuse is fitted. [ use manufacturers recommendation ]
• Inspect and fit a new fuel filter and in-tank strainer to the system. [ use only recommended parts ]
• Vehicles operating on dual fuel must have a quarter of a tank of petrol at all times.
• It is recommended that the vehicle be operated on petrol at least one day per week to keep the system operating correctly.

Failure to operate your vehicle in this way can degrade performance due to stale fuel and the formation of gums and varnish in the fuel system.
Bosch warranty does not cover failure due to the ingress of foreign matter, incorrect application or insufficient fuel supply. All fuel pumps returned under warranty will be inspected prior to claim settlement.

Before fitting new pump
Before fitting a replacement 12v fuel pump, please investigate the reason for the failure of the existing pump and rectify as neccessary.

Check the current draw of the fuel pump which should be less than 6.5 amps for EFI systems; for K and KE Jetronic systems 11 amps. Excessive current draw or noisy operation can indicate foreign material in the pump roller cell. Use only a fuse having the correctrating as specified by the vehicle manufacturer.

After removing the old pump from the vehicle, empty the contents of the pump into a container. Examine the fuel for signs of foreign
material including rust, rubber, varnish, plastic etc.
The complete system should be inspected and cleaned if neccessary; this includes the fuel tank, fuel rail, pressure regulator, tank pickup unit and strainer.

When refitting the hoses to the pump and fuel filter, take care not to damage the hoses as small rubber particles can circulate through the system and become jammed in the fuel pump, regulator or injector. Fit new fuel pump, check the current draw, check fuel rail pressure.

Bosch warranty does not cover failure that results from the ingress of foreign matter; incorrect application or damage resulting from pumps operating with insufficient fuel in the tank as in LPG conversions.

Edited by Chickenman

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You're avoiding the points and you've edited your original post.  No point in talking to someone who revises history and won't own what they said.  I didn't say Airtex was small, I said that they were just a run-of-the-mill aftermarket supplier.  Not some high performance ceramic turbine technology (whatever that is) race pump producer.

 

And my points about using what the big manufacturers use is valid and logical.  They did the research.  And they don't use prefilters.

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That's something.  No demands though, just the boilerplate "warranty will be voided" copy.  Quite a difference between a strainer and filter.  You'd think more is better, but it's not.  

post-8864-0-03734300-1467153983_thumb.png

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You're avoiding the points and you've edited your original post.  No point in talking to someone who revises history and won't own what they said.  I didn't say Airtex was small, I said that they were just a run-of-the-mill aftermarket supplier.  Not some high performance ceramic turbine technology (whatever that is) race pump producer.

 

And my points about using what the big manufacturers use is valid and logical.  They did the research.  And they don't use prefilters.

 I edit my post for Spelling errors. All the time. I don't like bad spelling. I also add links with my edits. Don't try and make out that I'm trying to change content with my edits.

 

And OEM manufactures certainly do use pre-filters ( Mesh screens or Socks ) for the in tank fuel pumps. . They're on Fords. Chevies, Honda' Nissan, BMW, Porsches, Audi, VW's and every car you buy off a show room floor. Have been since the 1980's. That's a fact and cannot be disputed. Period.

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And just so you don't think I'm trying to hide something with my edits. I have a brand new Fuel pump ( In tank ) sitting in front of me for my 1998 Audi. It has TWO pre-filters included in the installation package. Do you want me to include a picture???? 

 

Airtex has over 45 videos' of in-tank fuel pump replacements. EVERY one I've looked at has a pre-filter of some sort on them.

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Sure, let's see some evidence from Audi about a pre-filter.  Not a strainer, with big holes, but a filter for small particles.  I've seen the in-tank plastic screens used on the in-tank pumps.  Not the same as that G3 paper filter.

 

The basic point is understand how the pump works and what it needs.  You've just gone a bit hyperbolic in your recommendations.  And a lot of these guys are using pumps with flow rates much higher than they need.  What L6 out there needs 255 LPH?  That's over twice what the stock pump produced.  It's just not needed.  Pretty sure that Nissan used the same fuel pump for NA and turbo engines.

 

No offense to anybody out there using the 255 pump.  But it seems to lead to more problems than it's worth.

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Holy crap. All the poor guy has to do is put a screen mesh type prefilter from edelbrock or aeromotive (which I have been running for years, my walbros lasted my 8 years and still going) so he can enjoy his car.

 

You guys should start your own thread and argue there.

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Sure, let's see some evidence from Audi about a pre-filter.  Not a strainer, with big holes, but a filter for small particles.  I've seen the in-tank plastic screens used on the in-tank pumps.  Not the same as that G3 paper filter.

 

The basic point is understand how the pump works and what it needs.  You've just gone a bit hyperbolic in your recommendations.  And a lot of these guys are using pumps with flow rates much higher than they need.  What L6 out there needs 255 LPH?  That's over twice what the stock pump produced.  It's just not needed.  Pretty sure that Nissan used the same fuel pump for NA and turbo engines.

 

No offense to anybody out there using the 255 pump.  But it seems to lead to more problems than it's worth.

 

 

Absolutley zero problems with  mine. 

 

OP you shoudl consider what I did. You dont need to hack up your floor you could probably get away with installing the stuff in ur spare tirewell. Then your fuel system will be rock solid and surge free!

http://forums.hybridz.org/topic/124196-my-custom-fuel-setup/

 

I used this type of prefilter

http://pitstopusa.com/i-22954486-edelbrock-replacement-fuel-filter-blue-anodized-aluminum.html

I do not remeber the microns, but from my reseach you cannot go to small as the inlet of the walbro needs FLOW. You only want to keep major contamination out at best. If you restrict the inlet with a paper filter you will get major cavitation (from my experience) and thats why you are losing pressure.  A tank clean may be a good idea as well though. If you're passing rust through your fuel system your filters/pump and injectors will all eventually clog.

Edited by 240zdan

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Absolutley zero problems with  mine. 

 

OP you shoudl consider what I did. You dont need to hack up your floor you could probably get away with installing the stuff in ur spare tirewell. Then your fuel system will be rock solid and surge free!

http://forums.hybridz.org/topic/124196-my-custom-fuel-setup/

 

I used this type of prefilter

http://pitstopusa.com/i-22954486-edelbrock-replacement-fuel-filter-blue-anodized-aluminum.html

I do not remeber the microns, but from my reseach you cannot go to small as the inlet of the walbro needs FLOW. You only want to keep major contamination out at best. If you restrict the inlet with a paper filter you will get major cavitation (from my experience) and thats why you are losing pressure.  A tank clean may be a good idea as well though. If you're passing rust through your fuel system your filters/pump and injectors will all eventually clog.

 

240zdan, I like your set up. There does seem like a lot of room with that spare tire wheel well gone.

 

Is a surge tank required for a lift pump --> walbro pump system? 

Edited by palauoriginal

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240zdan, I like your set up. There does seem like a lot of room with that spare tire wheel well gone.

 

Is a surge tank required for a lift pump --> walbro pump system? 

 

Thanks. I spent a while researching and designing it. So far I am very happy. I can slide the car, brake hard, accelerate, all with the tank on E on rs3 tires pushing it to the limits and zero pump surge. One of the best mods I did to the car. If I had to put slicks on the car and go on a road course the fuel system woudl be the last thing on my mind. I know its up to the task.

 

To answer your question: Yes the lift pump pulls fuel out of the main tank and circulates it through the surge tank. Since the lift pump is designed to pull fuel up it does the magority of the work. The carter floods the surge tank. Additionally the excess fuel from the efi system returns back to the surge tank. This means means the surge tank is ALWAYS full (if not under slight pressure). That means the walbro is forced to take in fuel from the inlet. It runs quiet, consistent, and draws less amps. It doesnt matter how hard you corner, the 4l tank is walys ready to give the walbro what it needs since it has two sources, the carter and the return from the efi.

 

If the efi pump fails, the motor will not start/run. If the carter pump fails, the efi pump will suck the surge tank dry until it runs out of fuel. Neither is likely to blow the motor.

 

I much prefer a setup like this to a sump/fuel cell as it retains factory fuel tank/fuel fill/fuel guage. It has been dead reliable since the day I installed it, and I swear my walbro is 3x quieter, even under heat.

Edited by 240zdan

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