kj280z Posted April 7, 2011 Share Posted April 7, 2011 (edited) OK - I remember seeing a post about this but I can't find it. Been looking for an hour... Anyway - hopefully this is not a dupe. I finally got my LS1 Z on the road! The Walbro 255 fuel pump is gonna drive me crazy! It's obnoxiously loud whining (I can't stand whiners) I realize that most of you are going to quickly jump to the conclusion that my pump is having to work too hard or it has a clogged filter etc... Let me describe how I have the fuel system installed which "might" lead to a partial answer. 1. Fuel runs from the tank to an inline filter (brand new) then to the pump (Walbro 255) 2. All fuel lines were replaced with new 3/8" lines (feed and return) 3. I have aftermarket solid fuel rails. 4. Fuel enters the rail on the passenger side rear 5. The fuel rails are connected via AN fittings (proper size) and steel braided line across the front of the engine 6. I have an aeromotive FPR mounted on the back of the drivers side rail 7. The return runs off the FPR back to the tank 8. My pump is completely rubber mounted and insulated As you can see everything is BRAND NEW! My tank was reconditioned and is in good shape - it was also drained fully and there was zero sediment in it prior to startup Some things I'm suspecting and would like to hear your thoughts: 1. The inline filter might be causing the issue? 2. My previous motor was a high HP turbo L motor and I had an aeromotive pump installed at the time - it was ALSO very obnoxiously loud - In this instance, the only 2 components that were retained from the old system were the FPR and the fuel tank - maybe the pickup tube in the tank was partially blocked by the material the shop used to coat the inside? 3. My FPR does not keep pressure on the system when the motor is turned off - it has always done that - seems to be fine, but maybe worth noting Any ideas???? Edited April 7, 2011 by kj280z Quote Link to comment Share on other sites More sharing options...
Cable Posted April 7, 2011 Share Posted April 7, 2011 The external pumps are always noisy due to the fact they aren't muffled by the tank and/or the fuel itself. I recently replaced my stock GM in-tank pump (running a '02 Z28 tank in my Z) with a Walbro 255 and noticed its much louder than the stock pump. Quote Link to comment Share on other sites More sharing options...
kj280z Posted April 7, 2011 Author Share Posted April 7, 2011 (edited) Cable I would tend to agree, although a friend is running the Walbro 255 in his Z and mine is literally 10 times louder! It will drive you nuts kinda loud! So I do have a fair comparison and would find his to be perfectly acceptable, but mine has gotta have something causing it to be as loud as it is Edited April 7, 2011 by kj280z Quote Link to comment Share on other sites More sharing options...
Cable Posted April 7, 2011 Share Posted April 7, 2011 Then I'd lean toward a defective pump. If the brushes are bad or the vains are rubbing the pump housing, the motor will work extra hard and in turn be extra loud. Quote Link to comment Share on other sites More sharing options...
kj280z Posted April 7, 2011 Author Share Posted April 7, 2011 (edited) Hmm - It's brand new but anything is possible - the fact that my OLD Aeromotive pump did the same thing has me suspecting that there's more to it... I didn't have an inline filter on it so who knows... I have also been checking the Mustang forums and they all say that the Walbro 255 is VERY quiet although there are isolated cases where they have experienced the same condition I'm describing - still haven't found a post that solved the problem yet, but I'm still searching! Edited April 7, 2011 by kj280z Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted April 7, 2011 Administrators Share Posted April 7, 2011 I find the 255 to be a little on the loud side, comparatively, but it sounds like you might have something else going on. A few things come to mind... 1) The 3/8 feed line seems smallish. 2) What micron is the filter (between the tank and pump)? 3) I didn't notice you mention a filter between the pump and rails. Did I miss it? 4) How high is the pump mounted, relative to the tank? 5) What tank (240 or 280?) and is the supply line (to the filter) unmodified? P.S. The Aeromotive FPR has a reputation of not holding pressure. I don't like it, and don't agree with the arguments, but it's common. Also, regardless of the FPR, the system WON'T hold pressure if there is no functioning check valve, and I don't believe the 255 comes with one. Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted April 7, 2011 Share Posted April 7, 2011 The 255 doesn't come with a cheack valve. You need to buy one and mount it inline with the pump. I read on a porsche forum that that doesn't seem to lead to any problems, but with the pump running effecticly dry at startup I feel like it would lead to something down the road. This has me a little worried about installing mine on my ZX. Quote Link to comment Share on other sites More sharing options...
kj280z Posted April 7, 2011 Author Share Posted April 7, 2011 (edited) I find the 255 to be a little on the loud side, comparatively, but it sounds like you might have something else going on. A few things come to mind... 1) The 3/8 feed line seems smallish. 2) What micron is the filter (between the tank and pump)? 3) I didn't notice you mention a filter between the pump and rails. Did I miss it? 4) How high is the pump mounted, relative to the tank? 5) What tank (240 or 280?) and is the supply line (to the filter) unmodified? P.S. The Aeromotive FPR has a reputation of not holding pressure. I don't like it, and don't agree with the arguments, but it's common. Also, regardless of the FPR, the system WON'T hold pressure if there is no functioning check valve, and I don't believe the 255 comes with one. Thanks!!! Answers! I find the 255 to be a little on the loud side, comparatively, but it sounds like you might have something else going on. A few things come to mind... Should you be able to hear it from 20 feet away whining or inside the car with open headers? LOL it's REALLY bad! 1) The 3/8 feed line seems smallish. I was under the impression that this was the recommended size for typical stock Z car LS1 installs?? 2) What micron is the filter (between the tank and pump)? 100 Microns -6AN - standard Summit inline filter (new) - here's a link - it "might" be 40 Microns as indicated at this link - I will crawl under it tomorrow and reverify - also I'll try taking out the filter and let it free flow to see what happens http://www.summitrac...rts/SUM-230102/ 3) I didn't notice you mention a filter between the pump and rails. Did I miss it? Currently I do not have a filter between the pump and the rails 4) How high is the pump mounted, relative to the tank? The pump is mounted (mounted to the stock 280z fuel pump mounting points with a custom mount that I fabbed) kinda high with the suction on the bottom with a very short run to the tank and the outlet on the top - 5) What tank (240 or 280?) and is the supply line (to the filter) unmodified? I'm running the stock 1975 280Z tank that has been refurbished - the feed line is attached to the larger fitting that comes out of the tank, the return is hooked up to the smaller of the 2. The tank is unmodified except for the refurbishing - possibly some of the internal coating from the refurbishing could be clogging it?? P.S. The Aeromotive FPR has a reputation of not holding pressure. I don't like it, and don't agree with the arguments, but it's common. Also, regardless of the FPR, the system WON'T hold pressure if there is no functioning check valve, and I don't believe the 255 comes with one. Got it - I have been using this particular FPR for 8 years and it seems to have provided good service thus far - I will keep an eye on it Edited April 7, 2011 by kj280z Quote Link to comment Share on other sites More sharing options...
stravi757 Posted April 7, 2011 Share Posted April 7, 2011 Just thought I would add this. Maybe the problems are related? Before I did my turbo swap, my fuel pump was so quiet you could barely hear it. As soon as I swapped the 280zxt electronics my fuel pump made a noticeable noise(nothing extreme but you knew it was there). I went back to NA and the fuel pump went back to being quiet. I checked the voltage at the pump when it was turbo and it was reading 14.xx Always wondered why this was, maybe it has to do with something electrical? Quote Link to comment Share on other sites More sharing options...
kj280z Posted April 7, 2011 Author Share Posted April 7, 2011 Just thought I would add this. Maybe the problems are related? Before I did my turbo swap, my fuel pump was so quiet you could barely hear it. As soon as I swapped the 280zxt electronics my fuel pump made a noticeable noise(nothing extreme but you knew it was there). I went back to NA and the fuel pump went back to being quiet. I checked the voltage at the pump when it was turbo and it was reading 14.xx Always wondered why this was, maybe it has to do with something electrical? Yes we're going to check that tomorrow - We're actuating the pump using the wire provided within the stock Camaro harness (the company that modded my harness did a fantastic job but definitely worth checking) This thing is SOOO loud that it's gotta be more than that IMHO though, but it might be multiple small issues all adding up to one heck of a obnoxious noisy pump! I have never heard one even close to this!! unreal! Quote Link to comment Share on other sites More sharing options...
Nigel Posted April 7, 2011 Share Posted April 7, 2011 The 255 doesn't come with a cheack valve. You need to buy one and mount it inline with the pump. I read on a porsche forum that that doesn't seem to lead to any problems, but with the pump running effecticly dry at startup I feel like it would lead to something down the road. This has me a little worried about installing mine on my ZX. My 255 has a check valve. If you have an aftermarket FPR, and your fuel line is dropping pressure very quickly after shut down, then it is likely the FPR. It takes very little damage or wear to most FPR seats for them to leak. My pump is not that loud. I only really notice it when it's hot outside, and the car has been running for a long time. It also gets louder when the fuel level gets low, and there's less head pressure feeding the pump. I have the pump about as low as it can go without being lower than the tank. I've been considering one of these to slow the pump down when demand is low: http://www.turbomaga...ller/index.html Nigel '73 240ZT Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted April 7, 2011 Administrators Share Posted April 7, 2011 Where I was going with my questioning is this... A pump that cavities will experience reduced performance, reduced life, and make more noise. Keeping that in mind... 1) The 3/8 feed line seems smallish. I was under the impression that this was the recommended size for typical stock Z car LS1 installs?? 3/8" on the outlet is realistic, but 3/8" on the inlet would make me nervous. Couple examples: The stock '75 EFI supply line is roughly 15/32", and it's only good to about 250 HP. My Bosch 044 pump has an 18mm inlet. EFI pumps do a great job of pushing, but they are wimps when it comes to pulling. You want as little restriction as practical on the suction side. Which leads to... 2) What micron is the filter (between the tank and pump)?100 Microns -6AN - standard Summit inline filter (new) - here's a link - it "might" be 40 Microns as indicated at this link - I will crawl under it tomorrow and reverify - also I'll try taking out the filter and let it free flow to see what happens http://www.summitrac...rts/SUM-230102/ 40 micron is smaller than I would suggest running on the inlet (too much restriction, in my opinion). 100 micron is probably more appropriate. 3) I didn't notice you mention a filter between the pump and rails. Did I miss it?Currently I do not have a filter between the pump and the rails The reason I asked this is because you would normally want 'course' filtering on the inlet of the pump to protect it and to avoid cavitation, but you would also want something 'finer' after the pump to protect the injectors. I don't believe it's reasonable to expect one filter to do the whole job. 4) How high is the pump mounted, relative to the tank?The pump is mounted (mounted to the stock 280z fuel pump mounting points with a custom mount that I fabbed) kinda high with the suction on the bottom with a very short run to the tank and the outlet on the top - Sounds like you're in the ball park. Just make sure the pump isn't sucking the fuel uphill any more than necessary. 5) What tank (240 or 280?) and is the supply line (to the filter) unmodified?I'm running the stock 1975 280Z tank that has been refurbished - the feed line is attached to the larger fitting that comes out of the tank, the return is hooked up to the smaller of the 2. The tank is unmodified except for the refurbishing - possibly some of the internal coating from the refurbishing could be clogging it?? The 280 tank is much better suited I was concerned that you might be trying to use the 240 tank. RE: Tank coating... I have seen it de-laminate and plug the pick-up on a 280 tank. It happens. 1 Quote Link to comment Share on other sites More sharing options...
kj280z Posted April 7, 2011 Author Share Posted April 7, 2011 (edited) Where I was going with my questioning is this... A pump that cavities will experience reduced performance, reduced life, and make more noise. Keeping that in mind... I hear you - Luckily I've only driven it 10 miles but I need to resolve this asap so I can move forward finalizing the rest of the build 3/8" on the outlet is realistic, but 3/8" on the inlet would make me nervous. Couple examples: The stock '75 EFI supply line is roughly 15/32", and it's only good to about 250 HP. My Bosch 044 pump has an 18mm inlet. EFI pumps do a great job of pushing, but they are wimps when it comes to pulling. You want as little restriction as practical on the suction side. Which leads to... Hopefully it's good - I was using the stock fuel lines with my previous turbo L motor which made 365 rwhp and given that the 3/8" line is larger I was under the impression it was good - I'll do some more research on that... 40 micron is smaller than I would suggest running on the inlet (too much restriction, in my opinion). 100 micron is probably more appropriate. I thought it was 100 Micron, but after looking at the link it made me question it as well - My free flow test should provide some insight if this was contributing The reason I asked this is because you would normally want 'course' filtering on the inlet of the pump to protect it and to avoid cavitation, but you would also want something 'finer' after the pump to protect the injectors. I don't believe it's reasonable to expect one filter to do the whole job. Got it - I had plans to add it, but until I figure this out my thinking was to not introduce any more variables Sounds like you're in the ball park. Just make sure the pump isn't sucking the fuel uphill any more than necessary. I have it mounted vertically, any thoughts if mounting it horizontally (and as low as possible) would have any effect? Being that the suction side is level with the outlet on the tank with it's current mounting I thought that would be optimal, but I could be wrong The 280 tank is much better suited I was concerned that you might be trying to use the 240 tank. RE: Tank coating... I have seen it de-laminate and plug the pick-up on a 280 tank. It happens. I'm also wondering about this - my only solace is that I saw no signs of sediment or anything concerning in the fuel when I drained the tank - I started with a nice fresh tank of gas - but certainly something I'll have to keep an eye on... I have a brandy new 280Z tank that was actually opened, refurbished, and re-welded (very nice job) that if necessary I'll install once I've exhausted all other trouble shooting options I REALLY appreciate all the input!!! Edited April 7, 2011 by kj280z Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted April 7, 2011 Administrators Share Posted April 7, 2011 Hopefully it's good - I was using the stock fuel lines with my previous turbo L motor which made 365 rwhp and given that the 3/8" line is larger I was under the impression it was good - I'll do some more research on that... You lost me on that one. Are you saying you ran smaller than 3/8" on the INLET of the pump with the turbo L? I have it mounted vertically, any thoughts if mounting it horizontally (and as low as possible) would have any effect? Being that the suction side is level with the outlet on the tank with it's current mounting I thought that would be optimal, but I could be wrong I don't believe vertical or horizontal is of real world consequence. As Nigel said, it's about head pressure. If we had a choice, we would mount our pumps 40' below the tank I'm also wondering about this - my only solace is that I saw no signs of sediment or anything concerning in the fuel when I drained the tank - I started with a nice fresh tank of gas - but certainly something I'll have to keep an eye on... As an anecdote, the tank I was referring to wouldn't spit sediment. What you saw was a slightly blue tint in the fuel leaving the tank. You could drive the car normally for 5 to 15 minutes, the pump would become steadily noisier, then the engine would begin to run lean under load. Let the car sit for a while, and it would return to 'normal'. Quote Link to comment Share on other sites More sharing options...
ktm Posted April 7, 2011 Share Posted April 7, 2011 My 255 has a check valve. If you have an aftermarket FPR, and your fuel line is dropping pressure very quickly after shut down, then it is likely the FPR. It takes very little damage or wear to most FPR seats for them to leak. My pump is not that loud. I only really notice it when it's hot outside, and the car has been running for a long time. It also gets louder when the fuel level gets low, and there's less head pressure feeding the pump. I have the pump about as low as it can go without being lower than the tank. I've been considering one of these to slow the pump down when demand is low: http://www.turbomaga...ller/index.html Nigel '73 240ZT I've installed 3 Walbro's in my car. The first two were not loud at all, but the third one is a little loud. I can hear it when outside the car, but do not hear it inside the car. As for the FPR, the Aeromotives FPRs bleed down quickly after shut down. I even installed an Aeromotive check valve in after the Walbro and the FPR still quickly bled down. However, I've noticed no issues whatsoever in my logs and many others report the same experience. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted April 7, 2011 Administrators Share Posted April 7, 2011 I've installed 3 Walbro's in my car. You've got me curious, why 3? Quote Link to comment Share on other sites More sharing options...
ktm Posted April 7, 2011 Share Posted April 7, 2011 (edited) My fault. The first pump I fried due to low voltage. I was having constant issues with my alternators (dying on the road, driving on battery alone, etc.) and battery charge. Walbros are rather sensitive to voltage. The second replacement was an attempt to run down a very perplexing shut down problem. My car would run for 5 to 30 seconds and then immediately shut down. I checked both filters (pre and post pump), replaced the CAS, replaced the Walbro, and in the end it was a damn $5 relay controlling the LS1 coils. I bench flowed the 2nd Walbro and it was fine and is now a spare. Edited April 7, 2011 by ktm Quote Link to comment Share on other sites More sharing options...
kj280z Posted April 7, 2011 Author Share Posted April 7, 2011 (edited) You lost me on that one. Are you saying you ran smaller than 3/8" on the INLET of the pump with the turbo L? On the inlet side (the short hose from the pump to the tank) I believe I've always run 1/2". It's only around 8 inches long I think I initially misunderstood what you were asking - sorry bout that Edited April 7, 2011 by kj280z Quote Link to comment Share on other sites More sharing options...
kj280z Posted April 7, 2011 Author Share Posted April 7, 2011 (edited) Mine sounds like this except even louder, but the pitch is the same... though I'd share... Seems like there's a lot of people experiencing this with the Walbro pumps based on all the you tube posts!! http://www.youtube.c...feature=related My neighbors could hear mine and even made a comment about it! LOL Edited April 7, 2011 by kj280z Quote Link to comment Share on other sites More sharing options...
kj280z Posted April 13, 2011 Author Share Posted April 13, 2011 (edited) I have some information to share... I've tried the following: 1. Removed the inline filter and temporarily replaced it with a 1/2" rubber line - it made a marginal improvement - still not satisfied 2. Lowered the fuel pump - no change Tomorrow: Will experiment with having the pump source fuel from a separate fuel can... 1. it should tell me if I have something going on with my fuel tank 2. I will experiment with the separate fuel tank at a different height - if it quiets down when the tank is higher than the pump I may try a different mounting arrangement If none of this does the trick - I will double the rubber mounting and see if that has any effect I also suspect the fitting that came with the JCI setup that goes into the pump - it is very small and it comes off the pump at a 90 degree angle which is not needed with how I have the pump mounted. I might replace it and see if that helps... Anyone else have any other ideas while I'm at this?? Edited April 13, 2011 by kj280z Quote Link to comment Share on other sites More sharing options...
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