TexasQuest Posted December 16, 2014 Report Share Posted December 16, 2014 Anyone know the part # or where I can get the filter that's on top of the fuel tank under the access panel under the back floor board? I tried looking in the parts locator but didn't see it listed. Link to comment Share on other sites More sharing options...
Dad Posted December 16, 2014 Report Share Posted December 16, 2014 Not a factory filter, probably an add on, most people remove the small cone filter inside the pump inlet and install a larger inline filter.. more so when replacing a pump. Dad Link to comment Share on other sites More sharing options...
TexasQuest Posted December 16, 2014 Author Report Share Posted December 16, 2014 Interesting......guess that's why the parts diagram didn't show one. Link to comment Share on other sites More sharing options...
Dad Posted December 16, 2014 Report Share Posted December 16, 2014 Suggestion used to be a wix filter 12mm inlet and outlet, but I think it has been discontinued, next size might be 7/16 Link to comment Share on other sites More sharing options...
ucw458 Posted December 16, 2014 Report Share Posted December 16, 2014 A filter there is not needed. The hose for the inlet fits a 1/2" fitting loosely. You really shouldn't put anything smaller than 1/2" on there. That can restrict a high flow pump and cause cavitation. Link to comment Share on other sites More sharing options...
TexasQuest Posted December 17, 2014 Author Report Share Posted December 17, 2014 Alright I'll keep that as a reminder thanks. Link to comment Share on other sites More sharing options...
ucw458 Posted December 17, 2014 Report Share Posted December 17, 2014 For the record, cavitation doesn't affect just the pump. It affects fuel flow. Lets say your slightly clogged pre filter causes cavitation reducing fuel flow. When you are at WOT suddenly you don't have enough fuel to feed the injectors. You go lean, get detonation and possibly ruin your motor. All that over a filter you installed before the pump. There's a reason why most OEM manufacturers only put a strainer before the pump. Link to comment Share on other sites More sharing options...
TexasQuest Posted December 17, 2014 Author Report Share Posted December 17, 2014 Good to know ucw. Link to comment Share on other sites More sharing options...
Dad Posted December 17, 2014 Report Share Posted December 17, 2014 Mitsubishi used the strainer then also a small cone filter just before the pump that was installed in the pump inlet itself. I have an inline filter for about 7 years now with a walbro 255. If the filter before the pump gets clogged and you go lean, would not the filter after the pump get clogged if you didn't have an inline filter? I prefer to keep any debris from entering the pump. Dad Link to comment Share on other sites More sharing options...
G54Bstore Posted December 17, 2014 Report Share Posted December 17, 2014 Mitsubishi used the strainer then also a small cone filter just before the pump that was installed in the pump inlet itself. I have an inline filter for about 7 years now with a walbro 255. If the filter before the pump gets clogged and you go lean, would not the filter after the pump get clogged if you didn't have an inline filter? I prefer to keep any debris from entering the pump. DadTotally agree. I been running one for a lot of years as well. Never seen a issue unless you got a dirty tank or something in your gas. Link to comment Share on other sites More sharing options...
ucw458 Posted December 17, 2014 Report Share Posted December 17, 2014 You're forgetting pumps don't suck as well as they push. Any restriction on the pump inlet can cause a vacuum situation leading to reduced flow. While a 100 psi fuel pump wont be able to prime itself with a 5' vertical inlet line, It will however pump fuel 90' up a vertical 1/4" fuel line before the weight of the fuel equals the output pressure of the pump. What that means is a pre filter will get clogged to the point of failure faster than a post filter. You only need a screen before the pump to keep big chunks out that would jam the pump. Link to comment Share on other sites More sharing options...
DSMracespeed Posted December 17, 2014 Report Share Posted December 17, 2014 The small cone filter helps keep rust from going thru the pump if the pickup tube gets rusted. Jerry L. Link to comment Share on other sites More sharing options...
Dad Posted December 17, 2014 Report Share Posted December 17, 2014 I'm keeping my filter, one would think if flow was the issue then why did Mitsubishi put such a small cone filter inside the pump inlet? small surface area that can clog quickly, I would think the larger surface area of an inline filter won't clog so soon. Link to comment Share on other sites More sharing options...
Dad Posted December 17, 2014 Report Share Posted December 17, 2014 One note, too fine of a filter could cause a restriction, keep that in mind. I would suggest one such as a pre filter. probably have to look at the micron ratings. Dad Link to comment Share on other sites More sharing options...
ucw458 Posted December 17, 2014 Report Share Posted December 17, 2014 I'm keeping my filter, one would think if flow was the issue then why did Mitsubishi put such a small cone filter inside the pump inlet? small surface area that can clog quickly, I would think the larger surface area of an inline filter won't clog so soon. The cone filter wasn't meant for a walbro 255 that pumps 2.75x what the stock pump puts out. Besides FI and electric pumps were still a new thing. They didn't put cone filters in later cars. And many of us have had issues with that filter so most of us just toss it in the trash. Link to comment Share on other sites More sharing options...
G54Bstore Posted December 17, 2014 Report Share Posted December 17, 2014 Seems a little over thought IMO . If a stock pump can suck through a cone filter and a intank screen why can't it suck through a filter?I see what your trying to say I just don't by it. Nothing personal . Just sounds a little far fetched. My opinion. Link to comment Share on other sites More sharing options...
ucw458 Posted December 18, 2014 Report Share Posted December 18, 2014 Do you know the difference between a screen and a filter? The size of the holes the liquid can flow through makes a big difference. Filters trap small particles while screens only stop the bigger ones. The finer the filter the faster it gets clogged and the more pressure it takes to maintain flow. Nominal pump output of 100 psi is enough to push through a partially clogged post filter. A pre filter only has atmospheric pressure to induce flow. That's why pump inlets are larger. It's compensating for reduced pressure to maintain flow. A restriction on the inlet can reduce overall flow. Link to comment Share on other sites More sharing options...
G54Bstore Posted December 18, 2014 Report Share Posted December 18, 2014 No man I don't know the difference between a screen and filter... Really? Insult?Those inline filters people are using before the fuel pump have been used inline before fuel injection on carbs for a long time.Carb fuel pressure is low. If your fuel pump that's electric can not suction that low of a pressure something is wrong.It's also clear so you can see if it's getting dirty.No need to degrade me cause you got a different opinion you are trying to pass off as a fact or something dude .Yes I can tell between a filter and screen. Thanx for askin Link to comment Share on other sites More sharing options...
ucw458 Posted December 18, 2014 Report Share Posted December 18, 2014 Feel insulted if you want to but there was no insult in my statement. If your fuel pump that's electric can not suction that low of a pressure something is wrong. That is your opinion and it happens to be wrong. There's a simple phrase about physics, "physics never sucks it blows". What it means is the laws of physics state force doesn't pull, it pushes. No pump sucks material into it. They only push material out. Atmospheric pressure pushes material into the pump. If a pump tries to push more out than atmospheric pressure can replace into the inlet you get cavitation. Atmospheric pressure is a lower pressure than the pump output so you need a larger unrestricted inlet. Link to comment Share on other sites More sharing options...
G54Bstore Posted December 18, 2014 Report Share Posted December 18, 2014 LolNice way to be douchey under the radar.. funny stuff.Pumps push more than they suck lol derp derp. Got it. You are so right.Me and others will continue running them to protect our fuel pumps with out issues.I haven't seen any documented cases stating any of the problems you bring in to existence. Ok buddy was fun , I'm not gonna debate about it anymore. Thanx for your input, cheers mate! Link to comment Share on other sites More sharing options...
Dad Posted December 18, 2014 Report Share Posted December 18, 2014 Read #9 http://www.weldonracing.com/faq.phtml Expensive pumps with filters recommended on inlet side. Link to comment Share on other sites More sharing options...
ucw458 Posted December 18, 2014 Report Share Posted December 18, 2014 Read #9http://www.weldonracing.com/faq.phtml Expensive pumps with filters recommended on inlet side. Your link has little explanation and suggests too fine of a filter. Here's a link to Aeromotive's site with pictures and explanations why they recommend a larger/coarser filter. Also lots of pump manufacturers suggest using a filter because they don't know if you are installing the pump in a car that has an in tank screen or for example a 60s car that never had a screen. http://aeromotiveinc.com/wp-content/uploads/2014/12/TB_101_InletFilter02.pdf Bottom line:Inlet restrictions create vacuum, which causes cavitation, which in turn causes vapor-lock andfuel pump damage. Of course, drivability problems and even engine damage can result! Lesson:Don’t combine high flow, efficient fuel pumps with poor flowing inlet filters. Don’t use fuel linessmaller than the pump ports. Don’t use fuel tank pick-ups or tank outlets smaller than the line. Link to comment Share on other sites More sharing options...
Dad Posted December 18, 2014 Report Share Posted December 18, 2014 So you can use a filter before the pump Duh! Thats what we have been saying, just can't be so fine it restricts fuel. that link I put is not for cheap pumps, those recommendations are for a pump that can cost over a grand, you would think they know their s***. Link to comment Share on other sites More sharing options...
ucw458 Posted December 18, 2014 Report Share Posted December 18, 2014 So you can use a filter before the pump Duh! Thats what we have been saying, just can't be so fine it restricts fuel. that link I put is not for cheap pumps, those recommendations are for a pump that can cost over a grand, you would think they know their s***. If you read back I never said you can't. Just that it shouldn't be restrictive and if you have an in tank strainer an extra filter is not needed. Link to comment Share on other sites More sharing options...
G54Bstore Posted December 18, 2014 Report Share Posted December 18, 2014 (edited) So wth have we been discussing here then if you can use a filter that's no to restrictive like we have been saying?On a side note.. Wth would you need a in tank strainer and a cone strainer in the fuel line for if you got a filter before the fp and one after that's stock in the engine bay?You don't. Edited December 18, 2014 by G54Bstore Link to comment Share on other sites More sharing options...
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