Home
Forums
New posts
Search forums
Model-by-Model
K10
K10 General Discussion
K10 Micra Blogs
K10 Tuning & Mechanical
K10 Bodywork & Interior
March Superturbo (EK10) Forum
Nissan Pao (PK10) Forum
Nissan Figaro (FK10) Forum
Nissan BE-1 (BK10) Forum
K11
K11 General Discussion
K11 Micra Blogs
K11 Tuning & Mechanical
K11 Forced Induction tuning forum
K11 Bodywork & Interior
K11s in Motorsport
March Cabriolet (FHK11)
K12
K12 General Discussion
K12 Micra Blogs
K12 Tuning & Mechanical
K12 Bodywork & Interior
K13
K13 General Discussion
K13 Micra Blogs
K13 Tuning & Mechanical
K13 Bodywork & Interior
K14
K14 General Discussion
Stickers
What's new
New posts
New media
New media comments
New profile posts
Latest activity
Media
New media
New comments
Search media
Members
Registered members
Current visitors
New profile posts
Search profile posts
Log in
Register
What's new
Search
Search
Search titles only
By:
K10
K10 General Discussion
K10 Micra Blogs
K10 Tuning & Mechanical
K10 Bodywork & Interior
March Superturbo (EK10) Forum
Nissan Pao (PK10) Forum
Nissan Figaro (FK10) Forum
Nissan BE-1 (BK10) Forum
K11
K11 General Discussion
K11 Micra Blogs
K11 Tuning & Mechanical
K11 Forced Induction tuning forum
K11 Bodywork & Interior
K11s in Motorsport
March Cabriolet (FHK11)
K12
K12 General Discussion
K12 Micra Blogs
K12 Tuning & Mechanical
K12 Bodywork & Interior
K13
K13 General Discussion
K13 Micra Blogs
K13 Tuning & Mechanical
K13 Bodywork & Interior
K14
K14 General Discussion
Menu
Log in
Register
Install the app
Install
Home
K11 Tuning & Mechanical
Vacuum In Fuel tank Help.
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="SplanK" data-source="post: 550140" data-attributes="member: 93"><p><span style="font-family: 'Segoe UI'"><span style="color: #141414">I think the "release or air" is actually a positive pressure on the tank side rather than a vacuum. Petrol goes in as a liquid but at normal operating temperature can turn into a gas. As the fuel is bashed around the tank, it helps it vaporise and will also be heated as it passes through the fuel rail from the engine. </span></span></p><p> </p><p><span style="font-family: 'Segoe UI'"><span style="color: #141414">This is why its advised not to overfull your tank in summer, the heat increases the vaporisation of the fuel thus increases pressure. The filler cap also acts as a pressure release valve to avoid an over pressurisation (this can sometimes lead to people thinking they have a fuel leak when in fact it’s the fuel tank just venting!).</span></span></p><p> </p><p><span style="font-family: 'Segoe UI'"><span style="color: #141414">There are 4 pipes in a basic petrol tank. </span></span></p><p><span style="font-family: 'Segoe UI'"><span style="color: #141414">1st is pumped to the engine under pressure. This also goes through a fuel filter.</span></span></p><p><span style="font-family: 'Segoe UI'"><span style="color: #141414">2nd is the return feed (not all fuel pumped to the fuel rail is used, so there is a pressure valve (fuel pressure regulator) which keeps the fuel line pressurised at the correct pressure and releases excess back to the tank).</span></span></p><p><span style="font-family: 'Segoe UI'"><span style="color: #141414">3rd is the fuel filler pipe</span></span></p><p><span style="font-family: 'Segoe UI'"><span style="color: #141414">4th is a small vent pipe used for filling otherwise the pump would just click off all the time (although I think there is a fault with the Micra fuel filler pipe as it can be difficult at the best of times unless you hold it in the *perfect* position!)</span></span></p><p> </p><p><span style="font-family: 'Segoe UI'"><span style="color: #141414">Some cars have a more complex setup (such as swirl pots, multiple fuel lines, multi stage pumping.....) but I think that’s it for the Micra.</span></span></p><p> </p><p><span style="font-family: 'Segoe UI'"><span style="color: #141414">There could be a number of things that causes lean running from a sensor fault, iffy fuel pump, iffy fuel pressure regulator to even just being crap fuel. Personaly I would start with ensuring that all serviceable items are in good order before starting to dig deeper. Spark plugs, fuel filter (the one most people forget about!), oil change, there are no exhaust leaks, no vacuum leaks on any of the pipework (this can cause lean running/bad idle), sensors are working within accepable tollerences (some can be read using a simple multimeter, some may require a machine plugged into the OBD socket). You *MAY* be able to test the fuel pump by checking its resistance with a multimeter. I am not sure of the values or the how to so you may need to dig <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite13" alt=":)" title="Smile :)" loading="lazy" data-shortname=":)" /></span></span></p><p><span style="font-family: 'Segoe UI'"><span style="color: #141414">Did the garage not suggest what the problem was? Do you have the results of the test to hand you could post. My knowlage is mostly academic and basic, somebody may be able to assist further in diagnosing any fault you may have.</span></span></p><p> </p><p><span style="font-family: 'Segoe UI'"><span style="color: #141414">I know it sounds like a dig and please do not take this the wrong way, but are you 100% sure it's not a placebo effect? Sometimes after doing some work to your car, you think it’s made a difference however it’s made feck all difference. Bit like fitting an "induction kit". In reality, the poor kits do not make much difference apart from removing silencers and make it noisier, this giving the placebo effect of it adding a million and one HP (*slight over exaggeration but I think you can see where I am going with this!) <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite13" alt=":)" title="Smile :)" loading="lazy" data-shortname=":)" /></span></span></p></blockquote><p></p>
[QUOTE="SplanK, post: 550140, member: 93"] [FONT=Segoe UI][COLOR=#141414]I think the "release or air" is actually a positive pressure on the tank side rather than a vacuum. Petrol goes in as a liquid but at normal operating temperature can turn into a gas. As the fuel is bashed around the tank, it helps it vaporise and will also be heated as it passes through the fuel rail from the engine. [/COLOR][/FONT] [FONT=Segoe UI][COLOR=#141414]This is why its advised not to overfull your tank in summer, the heat increases the vaporisation of the fuel thus increases pressure. The filler cap also acts as a pressure release valve to avoid an over pressurisation (this can sometimes lead to people thinking they have a fuel leak when in fact it’s the fuel tank just venting!).[/COLOR][/FONT] [FONT=Segoe UI][COLOR=#141414]There are 4 pipes in a basic petrol tank. [/COLOR][/FONT] [FONT=Segoe UI][COLOR=#141414]1st is pumped to the engine under pressure. This also goes through a fuel filter.[/COLOR][/FONT] [FONT=Segoe UI][COLOR=#141414]2nd is the return feed (not all fuel pumped to the fuel rail is used, so there is a pressure valve (fuel pressure regulator) which keeps the fuel line pressurised at the correct pressure and releases excess back to the tank).[/COLOR][/FONT] [FONT=Segoe UI][COLOR=#141414]3rd is the fuel filler pipe[/COLOR][/FONT] [FONT=Segoe UI][COLOR=#141414]4th is a small vent pipe used for filling otherwise the pump would just click off all the time (although I think there is a fault with the Micra fuel filler pipe as it can be difficult at the best of times unless you hold it in the *perfect* position!)[/COLOR][/FONT] [FONT=Segoe UI][COLOR=#141414]Some cars have a more complex setup (such as swirl pots, multiple fuel lines, multi stage pumping.....) but I think that’s it for the Micra.[/COLOR][/FONT] [FONT=Segoe UI][COLOR=#141414]There could be a number of things that causes lean running from a sensor fault, iffy fuel pump, iffy fuel pressure regulator to even just being crap fuel. Personaly I would start with ensuring that all serviceable items are in good order before starting to dig deeper. Spark plugs, fuel filter (the one most people forget about!), oil change, there are no exhaust leaks, no vacuum leaks on any of the pipework (this can cause lean running/bad idle), sensors are working within accepable tollerences (some can be read using a simple multimeter, some may require a machine plugged into the OBD socket). You *MAY* be able to test the fuel pump by checking its resistance with a multimeter. I am not sure of the values or the how to so you may need to dig :)[/COLOR][/FONT] [FONT=Segoe UI][COLOR=#141414]Did the garage not suggest what the problem was? Do you have the results of the test to hand you could post. My knowlage is mostly academic and basic, somebody may be able to assist further in diagnosing any fault you may have.[/COLOR][/FONT] [FONT=Segoe UI][COLOR=#141414] [/COLOR][/FONT] [FONT=Segoe UI][COLOR=#141414]I know it sounds like a dig and please do not take this the wrong way, but are you 100% sure it's not a placebo effect? Sometimes after doing some work to your car, you think it’s made a difference however it’s made feck all difference. Bit like fitting an "induction kit". In reality, the poor kits do not make much difference apart from removing silencers and make it noisier, this giving the placebo effect of it adding a million and one HP (*slight over exaggeration but I think you can see where I am going with this!) :)[/COLOR][/FONT] [/QUOTE]
Verification
Post reply
Home
K11 Tuning & Mechanical
Vacuum In Fuel tank Help.
Top