Forum Index
Jeep Horizons HomeLinksJeep Horizons Tech Write-upsJeep newsLand useContact

 Watched TopicsWatched Topics   FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Can a bad gas cap cause this?


 
Post new topic   Reply to topic     Forum Index -> Cherokee Forum
View previous topic :: View next topic  
Author Message
IndyMatt
Member


Joined: 09 Sep 2006

PostPosted: Wed Sep 13, 2006 4:55 pm    Post subject: Can a bad gas cap cause this? Reply with quote

Referring to my problem in this thread: http://www.jeephorizons.com/phpbb/viewtopic.php?t=9337&sid=003c8366386a5c25175af2c7ab765aed

I've been through several fuel pumps recently. I think this latest time I narrowed it down to the fuel relay however; intuition tells me this may not be the root cause of the problem. In another forum that I belong to, someone mentioned that if the gas cap is not allowing the tank to breathe, then this could very well result in the symptoms I've been getting with this Jeep (running sluggish, no power, 15psi fuel rail pressure).

I'm curious if anyone here has had experience with a bad gas cap not allowing the tank to breathe. Please share.

Thanks- Matt
Back to top
View user's profile Send private message
ThePhantum
Pissed-Off Admin
Pissed-Off Admin


Joined: 23 Jan 2004
Location: I knew it...I'm surrounded by Assholes!

PostPosted: Wed Sep 13, 2006 5:27 pm    Post subject: Reply with quote

I don't think so. If the cap was bad you would get a check engine light, but I doubt it would eat fuel pumps. The cap doesn't allow the tank to pressurize...just the opposite actually...it needs to be able to hold a vacuum. That's how the EVAP system makes sure there are no leaks in the tank.
_________________

97 XJ Sport with a bunch of stuff
Quote:
Never argue with idiots, they drag you down to their level and beat you with experience
Back to top
View user's profile Send private message AIM Address Yahoo Messenger MSN Messenger
IndyMatt
Member


Joined: 09 Sep 2006

PostPosted: Thu Sep 14, 2006 3:51 am    Post subject: Reply with quote

Thanks for the feedback. I still haven't put very many miles on it since the latest pump install...we'll see how things go.

Matt
Back to top
View user's profile Send private message
kaos
Member


Joined: 10 Jan 2006
Location: Iceland

PostPosted: Fri Sep 15, 2006 1:46 am    Post subject: Reply with quote

I'm not quite sure of my facts here, so take this with your preferred dose of salt, but: While Phantom is right in that some amount of vacuum in the fuel tank is normal, and should not be released by the fuel cap, surely this is regulated somehow? I *think*, however, that this is done through a breather line to the evap canister in the engine bay, rather than by the gas cap. You might want to check that this line is free of obstruction / unkinked.

Best regards,
--
Kári, in Iceland.
Back to top
View user's profile Send private message Visit poster's website
94z07
Member


Joined: 09 Dec 2006

PostPosted: Sat Dec 16, 2006 10:23 pm    Post subject: Reply with quote

IIRC the gas cap is NOT supposed to breathe.

There is a line that runs to the canister in the engine compartment that vents the gas tank.

Look at a snorkle kit and you'll see that this is one of the things that ppl route up high so they can go jeep swimming.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic     Forum Index -> Cherokee Forum All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Visit links4jeeps.com for write-ups, forums and clubs




Jeep®, Wrangler, Cherokee, Liberty and Grand Cherokee are copyrighted and trademarked to Chrysler LLC.
jeephorizons.com is not in any way associated with or endorsed by the Chrysler LLC.
All other content is copyright Jeep Horizons 2004-2008.
Tech write-ups Links Discussion board Land use News Site Map Terms of Use

Powered by phpBB © 2001, 2005 phpBB Group