Recent Topics
2009 Civic 1.8L rough idle with the AC on
by Doog
07/24/14 09:24 AM
Girlfriend buying 2015 Subaru Forrester, 6-manual
by k24a4
07/24/14 08:06 AM
Pur 1 - 4,000 miles - hole in bottom
by thomasew
07/24/14 07:36 AM
insert image into post
by thomasew
07/24/14 06:53 AM
Happy Birthday Pablo
by Shannow
07/24/14 06:38 AM
My Father's new toy! (Alfa Romeo Spyder)
by Patman
07/24/14 06:37 AM
Algerian airliner goes missing...
by Shannow
07/24/14 06:36 AM
Mt. Washington
by Pablo
07/24/14 06:35 AM
Cooking alcohol.
by Silk
07/24/14 05:44 AM
G-Oil back at Walmart?
by zanzabar
07/24/14 02:29 AM
Marvel Mystery Oil on Suzuki GSX1250FA
by Franklim
07/24/14 01:03 AM
Biology and Chemistry
by MolaKule
07/24/14 12:05 AM
Newest Members
Patrick0525, offroad1, cnowak1, Dave13, HuskyPilot
50737 Registered Users
Who's Online
95 registered (13Tacoma, 2010_FX4, 01_celica_gt, 2004tdigls, 123Saab, 137_Trenton, 5 invisible), 1829 Guests and 261 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
50737 Members
64 Forums
216712 Topics
3411001 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG

Topic Options
#2767398 - 10/09/12 09:26 AM Symptoms of a bad gas cap?
wolf_06 Offline


Registered: 06/11/12
Posts: 409
Loc: Atlantic, Canada
Any of you experience a bad gas cap? If this can affect engine performance, fuel trim or fuel pressure? fuel economy?

Thanks!
_________________________
2011 Chevy Cruze 1.8L 6AT
Syntec Edge 5w30 - OEM filter

Top
#2767401 - 10/09/12 09:30 AM Re: Symptoms of a bad gas cap? [Re: wolf_06]
Quest Offline


Registered: 12/19/04
Posts: 6261
Loc: beaver land EH?
on OBD-II cars: a bad (not sealing properly) gas cap will throw you a code.

Q.
_________________________
"Internet discussion boards act as echo chambers for conspiracy dittoheads" A.Allen

Top
#2767404 - 10/09/12 09:32 AM Re: Symptoms of a bad gas cap? [Re: Quest]
Charlie1935 Offline


Registered: 05/18/08
Posts: 315
Loc: DuQuoin, Illinois
It will give a code for evaporation system leak usually.
_________________________
Charlie

Top
#2767417 - 10/09/12 09:53 AM Re: Symptoms of a bad gas cap? [Re: wolf_06]
440Magnum Offline


Registered: 02/01/09
Posts: 6099
Loc: Texas
Electric fuel pumps for EFI generate pressures on the order of 50 psi, the gas cap holds a pressure of 2-3 pounds. So at most its going to make a few percent difference in fuel pressure, and most likely not even that since the fuel pressure is usually regulated. So I'd say you'd never see a difference in performance at all, just the code for an evaporative emissions fault.
_________________________
'66 Dodge Polara & '69 Dodge Coronet R/T both 440/727
'08 Ram 1500 4.7/545RFE
'12 Challenger SRT8 392/6-speed
'99 Cherokee 4.0, '11 Grand Cherokee 3.6

Top
#2767479 - 10/09/12 11:19 AM Re: Symptoms of a bad gas cap? [Re: wolf_06]
WishIhadatruck Offline


Registered: 05/09/06
Posts: 1249
Loc: Grand Rapids, MI
The only thing I've ever noticed is that my check engine light comes on. I've never noticed a change in how the vehicle performs.
_________________________
1996 Buick Roadmaster Wagon
2001 Pontiac Grand Prix
2003 2500 Suburban, 8.1L

Top
#2767495 - 10/09/12 11:39 AM Re: Symptoms of a bad gas cap? [Re: wolf_06]
Donald Offline


Registered: 03/21/04
Posts: 13180
Loc: Upstate NY
I drove for a few miles with the gas cap held neatly in the gas flap. No code or anything.
_________________________
2001 Jeep Grand Cherokee Laredo 4.0 - PP & M1
1999 Dodge Ram 2500 w/Cummins - Rotella T6 & M1
Amsoil ATF in both vehicles & Magnefine filter.

Top
#2767501 - 10/09/12 11:43 AM Re: Symptoms of a bad gas cap? [Re: Donald]
Trav Offline


Registered: 11/20/06
Posts: 9112
Loc: MA, Mittelfranken.de
It wont until the system runs an EVAP test.
_________________________
ASE L1, Master. Deutsch Meisterbrief.

Top