Engine & Gearbox FR-V Petrol - fuel tank pressure / EVAP system?

Discussion in '1st Generation (2004-2011)' started by Princepugh, Tuesday 30th Apr, 2013.

  1. Princepugh Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom David Sheffield
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    Hiya

    I've owned my 57 plate 1.8 FR-V a couple of months now - the family and I have been loving driving around in it and many of my friends and colleagues have commented on how good it looks and how good the driving position feels.

    This all makes me happy, however, I’ve noticed that on a few occasions when I've opened the fuel filler cap there’s been a release of pressure followed by a smell of fuel, which leads me to suspect that the tank is becoming pressurised. I’ve also noticed that there’s sometimes an audible ticking noise from the engine bay when the motor is warm.

    I'm pretty convinced this is not valve tick due to the intermittent nature. I haven't been able to positively link the tick and the tank pressure, however, as I'm not much of a believer in coincidences, I'm wondering if there's a problem with the EVAP system, particularly the purge solenoid, which is not venting pressure through the charcoal canister?

    I do have a while of warranty left under which I can pursue this, however, as I like to be as informed as possible on technical issues, I’m wondering if anybody has any words of advice, or back-ground reading/ technical articles I can refer to prior to me following up.

    Did a search on here but couldn’t find anything specific to the purge valve or EVAP systems.

    Grateful of any useful feedback/ advice.

    BTW AFAIAA the engine is the R18A1 unit which is most likely shared with incarnations of the Civic and others.

    Thanks in advance for any feedback.

    David
     
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  2. Ichiban Founder Staff Team

    England CJ Leeds
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    Hi David ,petrol fume pressure build up nothing to be worried about its quite natural for that to happen, it also shows your petrol cap is working perfectly.

    if the cap was not gas tight the rate of petrol evaporation will be higher and you would question where is my petrol going.:Wink:
     
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  3. Ichiban Founder Staff Team

    England CJ Leeds
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    Its sounds like a sewing machine then that is normal it will be the fuel injectors.
     
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  4. i-DSI Expert Advisor ★ ★ ★ ★ ★

    Belgium Aalst
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    Hi David,
    The thicking is intermittent? Than it's not the injectors, but the EGR valve. I have the same noise in both Civic 1.4 I-DSI petrol and Accord 2.0 i-VTEC. Very normal, nothing to worry about.

    Ichiban,
    When opening the fuel cap you do not hear any build up of fumes escape, but you do hear air coming in the tank. This is because the fuel pump creates a slight underpressure in the fuel tank.

    But again, Dave, as Ichiban says, this is also very normal and proof that all works normal. If the underpressure becomes a bit to high than the little valve in the fuel cap lets a bit of air in the tank so your engine will not starve from fuel.

    All seems perfect with your car Dave. No worries at all.
     
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  5. Princepugh Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom David Sheffield
    81
    33
    Hi all - thanks for your replies.

    Roger re the fuel cap - it certainly is doing its job holding the pressure in, however, I'm convinced that this is +ve pressure, not -ve as the petrol fumes are very strong. In this case, my expectation is that the EVAP system is not working as it is supposed to take the excess fuel vapour and pass through to the charcoal cannister for relase via the EVAP valve for combustion. As such, the system can surely not be operating effectively if I am releasing excess hydrocarbons to the atmosphere when I undo the cap. My previous two cars, both fitted with charcoal cannister based EVAP systems have never blown vapours out when the filler cap is removed.

    Gonna talk to our local Honda-tech tomorrow if I can blag a couple of minutes with them.

    Still interested in feedback!

    D
     
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  6. i-DSI Expert Advisor ★ ★ ★ ★ ★

    Belgium Aalst
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    Hi David,
    A fuel tank has 2 systems: it must be able to cope with under and overpressure.
    When driving to the petrol station to fill up, you should always have underpressure as the volume of fuel decreases.
    After filling up and parking in the sun, your fuel tank might get a bit overpressure.
    For the first case, the fuel cap has a valve that lets air in to the tank. If a car ever breaks down when driving, opening the fuel cap to let in air and the car starts again? => valve is stuck closed in the fuel cap.
    For the second case, there's indeed the EVAP system to store vapours and burn them afterwards in the engine (at least.... in modern cars). Motorcycles use also the fuel cap to release the vapours in the atmosphere in case of overpressure.
    Are you really sure there's overpressure? Isn't there always a smell of petrol when opening the cap?
     
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  7. Beefy Expert Advisor ★ ★ ★ ★ ★

    United Kingdom Stoke
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    there is allways a smell of fuel when opening the petrol cap my friend. petrol is in nature rather pungent in smell and there is nothing a manufacturer can do to counteract this.
     
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  8. Ichiban Founder Staff Team

    England CJ Leeds
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    Try driving my first gen it smells of petrol all the time ...
     
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  9. Princepugh Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom David Sheffield
    81
    33
    Hello again!

    At the risk of coming across a bit 'wrong', perhaps I should clarify.

    Probably about half of the time, when I take the filler cap off at the petrol station there is a significant gush of outward pressure and a strong smell of petrol fumes. I've driven many cars and ridden many motorcycles and never experiened this level of pressure before, hence my concern.

    Some fuel vapour smell I'd expect, of course; and maybe some pressure differential when I release the cap but this is significant enough for me to be concerned.

    I haven't been able to correlate the pressure with any particular conditions, time of day etc. as yet but I'm still thinking that the ticking noise cannot be a coincidence as it's not regular enough to be valve or injector and I'm not sure how many other solenoids live under the bonnet.

    Anyways, as noted, I'm going to follow-up with Honda while I still have some (third party) warranty. Will let you know how things go.

    Thanks

    D
     
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  10. i-DSI Expert Advisor ★ ★ ★ ★ ★

    Belgium Aalst
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    Hi David,
    The EGR valve is intermittent and not regular. You can hear that valve coming on and off.
     
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  11. Beefy Expert Advisor ★ ★ ★ ★ ★

    United Kingdom Stoke
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    take your car to a dealer and demmonstrate the fault. my oppinion is you are new to the vehicle and its very likely there is nothing abnormal. best to put your mind at ease but i wouldn't get too worked up about it.
     
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  12. Princepugh Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom David Sheffield
    81
    33
    Sorry, should have updated the thread sooner - spoke to the service manager at my local Honda dealer who, in-line with many of the posters on here, advised that this was normal and nothing to be concerned about. Whilst my OCD side is not totally convinced, I've persuaded my better self that your feedback is reassuring and that this isn't a major problem, although I will discuss with the mechanic at my next service ;-)

    Annoyingly/ pleasingly, there's been no over-pressure for the last handful of fill-ups.

    David
     
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