|
|
|
|
Thread Tools | Display Modes |
01-02-2020, 01:10 PM | #1 |
Scooby Guru
Member#: 51282
Join Date: Dec 2003
Chapter/Region:
SCIC
Location: Pasadena, CA
Vehicle:98 RS black & blue from parking |
04 WRX gas tank does not pressurize, P1446
Hi all,
I'm working on with a swapped GC with 04 WRX everything-ECM, gas tank, evap system, engine, everything. The only GC component that might be relevant is the filler neck, which I'm using with the 04 "shut valve", the little two-way port with a brass button that sits toward the gas cap. I cannot get the system to pressurize and it is driving me crazy. When I open the gas cap, there's no difference from the ambient pressure, no "whoosh" from the seal opening. I do have a code 1446 "Fuel Tank Sensor Control Valve Circuit Low". No other codes. I believe this is caused by the actual low pressure in the tank, not a fault in the circuit or the sensor. There is definitely a mechanical condition that's not right so my approach has been to try and correct that condition first. I have disassembled, cleaned, bench tested and replaced nearly the entire system. Here's what I've tried so far: * Smoke tested evap / charcoal canister for leaks * Replaced entire gas tank, with lines, float, sensor, and VSV * Bench tested drain valve * Smoke tested purge line running to the fuel rail, replaced purge valve itself * Tested wiring running from the ECM to fuel tank harness, I don't see any shorts and the ground signals from the various gas tank sensors are all continuous to the ECM. * Tested signal from the internal fuel pressure sensor to the ECM while the car is running. According to AllData, the ECM wants to see more than 10.9v from the pressure sensor. I get ~12.4v sent back to the ECM. I am totally stumped what could be going on here. The fuel / evap system is not that complicated... what could possibly cause a tank not to hold pressure? I did reuse the seal from the fuel pump cage to the tank but I have never seen those leak so badly that the tank wouldn't pressurize. What else can I try next to diagnose and correct this issue? Edit, here's the page from the service manual I've been working off:
* Registered users of the site do not see these ads.
Last edited by jamesfacts; 05-18-2020 at 04:19 PM. |
01-09-2020, 09:56 AM | #2 |
Scooby Newbie
Member#: 63922
Join Date: Jun 2004
Location: Long Island, NY
Vehicle:2003 WRX World Rally Pearl Blue |
evap
First of all, there should be no pressure in the system unless it is very hot causing the fuel to expand, like on a 90 degree day. Evap systems check by applying vacuum via purge valve to the fuel tank and close the vent valve. It then expects to see vacuum on the sensor. To check it, you need to smoke test at the test port or purge valve and actuate the vent valve so it seals. look for smoke with a bright white light.
|
04-17-2020, 01:04 PM | #3 |
Scooby Newbie
Member#: 490614
Join Date: Aug 2018
|
p1446
jamesfacts, Did you find a resolution to this problem? I seem to have a similar problem.
|
04-17-2020, 02:05 PM | #4 |
Scooby Specialist
Member#: 191557
Join Date: Oct 2008
Chapter/Region:
TXIC
Location: Rockwall-East DFW
Vehicle:2004 WRX Wagon WRB not so minty fresh |
I chased EVap & tank related problems for nearly 2 years... cannot count how many times I replaced almost everything...
I did get the 1445 code once along with a punch of other codes that were all EVAP related. Mine turned out to be a fuel saturated charcoal canister. The canister should feel light in weight when picked up. IF it has a heavy/dense feel to it, then the tank/canister were "topped off" while filling an fuel got into the canister itself. 2 easy tests: 1. remove the canister and hold it in your hand or actually weight it, it shouldn't be more than a pound or so 2. turn the inlet/outlet ports 90* to the ground, if fuel comes out there is a problem, even if little charcoal pellets fall out, canister needs replaced. If the canister is contaminated, it will drive the engine mounted purge solenoid and the rear evap purge solenoid bonkers. So far for quality EVAP parts rockauto has been the best value. Lastly check all the EVAP hoses and especially the fill-neck to tank hoses. I had a fine tear in my neck2-tank coupler and found that the worm-gear clamps had punctured the rubber allowing a leak. ~Rob |
04-17-2020, 06:15 PM | #5 |
Scooby Newbie
Member#: 490614
Join Date: Aug 2018
|
Thanks
Thanks for the reply, I will keep digging away at it.
|
05-17-2020, 06:11 PM | #6 | |||
Scooby Guru
Member#: 51282
Join Date: Dec 2003
Chapter/Region:
SCIC
Location: Pasadena, CA
Vehicle:98 RS black & blue from parking |
Quote:
Quote:
Interestingly, I do notice the idle stumble just a hair when the underhood purge valve is activated. That suggests to me that there is a leak somewhere in the evap system... or it could be a perfectly normal drop in intake manifold pressure as a result of the volume of the evap lines? Quote:
What an incredibly complex set of vac lines and solenoids back there huh Good luck! Please do post here if and when you figure it out. |
|||
05-17-2020, 07:42 PM | #7 |
Scooby Newbie
Member#: 513021
Join Date: Mar 2020
Chapter/Region:
AKIC
Location: the sixth borough
Vehicle:2005 9-2x desert silver |
When you smoke tested it where was smoke coming from?
|
05-17-2020, 09:45 PM | #8 |
Scooby Newbie
Member#: 470981
Join Date: Jul 2017
Chapter/Region:
Tri-State
Location: Delaware
Vehicle:2008 Legacy GT spec DGM |
You can pinch or block off the vent hose, otherwise you would need a powerprobe and a wiring diagram to apply power and/or ground to the vent valve to seal the system prior to smoking it.
|
05-18-2020, 04:36 PM | #9 |
Scooby Guru
Member#: 51282
Join Date: Dec 2003
Chapter/Region:
SCIC
Location: Pasadena, CA
Vehicle:98 RS black & blue from parking |
Edited the original post to include the FSM diagram.
It seemed like the system was fairly airtight, but I never tested from the charcoal canister (#6 ) forward. I capped the lines from the charcoal canister to the drain valve (#8) since I think that's open? I also think from 7 to to 10 is normally open? I also never smoke tested with the tank in the test circuit because I figured it would take too long to fill the whole tank with smoke. The more I think about it now... I think the better way to pressure test the evap system is to pull vacuum on the purge line under the hood with a hand vac pump. At rest the entire system should be air tight (from the purge valve line), right? I've been using wooden dowels inside of rubber caps to cap the system section by section. Which direction would you test from? |
05-18-2020, 08:35 PM | #10 |
Scooby Newbie
Member#: 470981
Join Date: Jul 2017
Chapter/Region:
Tri-State
Location: Delaware
Vehicle:2008 Legacy GT spec DGM |
From the purge line that goes to the tank. I'm not sure what kind of machine you're using, but it does take a couple minutes for it to fill the system. Does it have a gauge to show leak size? (i.e. .0020, .0030, etc) The professional machines say anything under .0020 is acceptable but I've found that not to be true. The system is sealed when that little pill flat lines. When you're filling it with smoke, remove the gas cap. When the smoke starts coming out, obviously put the cap back on, but it's an indication that its filling up and should be pretty full throughout.
|
05-18-2020, 08:38 PM | #11 |
Scooby Newbie
Member#: 470981
Join Date: Jul 2017
Chapter/Region:
Tri-State
Location: Delaware
Vehicle:2008 Legacy GT spec DGM |
https://forums.nasioc.com/forums/showthread.php?t=1183535
Could this pertain to you? |
05-21-2020, 03:07 PM | #12 | |
Scooby Guru
Member#: 51282
Join Date: Dec 2003
Chapter/Region:
SCIC
Location: Pasadena, CA
Vehicle:98 RS black & blue from parking |
Quote:
This is the machine I used: https://www.ebay.com/itm/Redline-Det...t/362703747933 I can probably go borrow it again. It could... but I would rather fix the actual issue. I had previously set 1446 to permanently "not ready" with an ECU flash but the tank wasn't pressurized then either so something was definitely not right. |
|
05-21-2020, 10:08 PM | #13 |
Scooby Newbie
Member#: 470981
Join Date: Jul 2017
Chapter/Region:
Tri-State
Location: Delaware
Vehicle:2008 Legacy GT spec DGM |
May be a dumb question, but did you have it hooked up to an air compressor? If you pinch or cap off the vent hose and smoke it through that purge line that runs to the back of the car, the little pill should flat line if there are no leaks. This does not confirm if a valve or solenoid is working properly but you'll be able to rule out rusty lines, fuel pump seal, filler neck and gas cap.
|
05-26-2020, 10:09 PM | #14 | |
Scooby Guru
Member#: 51282
Join Date: Dec 2003
Chapter/Region:
SCIC
Location: Pasadena, CA
Vehicle:98 RS black & blue from parking |
Quote:
|
|
05-26-2020, 11:06 PM | #15 |
Scooby Newbie
Member#: 470981
Join Date: Jul 2017
Chapter/Region:
Tri-State
Location: Delaware
Vehicle:2008 Legacy GT spec DGM |
To each their own. I've never used a vac pump to check for leaks but there's more than 1 way to skin a cat. Good luck!
|
06-01-2020, 03:22 PM | #16 | |
Scooby Guru
Member#: 51282
Join Date: Dec 2003
Chapter/Region:
SCIC
Location: Pasadena, CA
Vehicle:98 RS black & blue from parking |
Quote:
https://www.skf.com/mityvac/products...leeding/mv8020 First, I capped off the purge line running to under the hood, to reduce the volume of air I would need to pull vac on. I did test the line itself and it does hold pressure. Then, I tested the system in chunks, working from the charcoal canister. I capped the two big lines running out of the charcoal canister and verified that the canister itself is air tight. Then I tried to pull vac on the tank itself, working from this line here: The gas tank did hold pressure, so then I moved on to the other big line from the canister, the one that runs to the drain valve. That line does not hold vacuum. My understanding is that the drain valve should stay closed at rest, right? I know it does open sometimes to vent the canister to atmo, but I'm not sure what triggers it to open. Here's the only thing I could find in the FSM on the drain valve: So, two questions: Should the drain valve be normally closed? Is it an issue that it's open to the atmosphere at rest? Can I safely cap the line to the drain valve and test if that makes the CEL go away? Thanks! |
|
06-02-2020, 11:45 PM | #17 |
Scooby Guru
Member#: 487
Join Date: Nov 1999
Chapter/Region:
TXIC
Location: Houston TX
Vehicle:1998 /2005 STunIcorn Acadia Green USDM 22b |
Hey y'all
Me and James be both struggling with our own CC8 swap issues Been rapping about both owners issues......for months! IMO James' issue more technical Mainly bc of CA emission laws Did you know that if you bring in a swapped car, inspection technician busts out a book with pictures of said manufacture's engine bay? Then your screwed James had perfectly running (no CE lite what so ever) swapped GC8 So in a nutshell He learned that if you do have a swapped car, EVERYTHING must be swapped Including in this case, fuel tank ***8216;system' This is mandatory to get registered in CA Crazy Crap Then this obd2 code popped up So here is my 2cents Plz y'all, James more technical about stuff like this Critiquing my opinion encouraged !!! 1) if J caps off the hose, might work However, might also be noticed by the CA Nazi inspectors That might be BAD 2)I said to take off that valve....clean tht thing with brake cleaner/MAF cleaner whatever Then test continuity on said valve. Bc 2wire system J told me that white valve is $80 NP throwing parts at the issue.....if you know issue or your rich I'm really hoping that plastic valve is stuck one way bc car came from NE Help my friend and crush my crappy theory!!!! |
06-02-2020, 11:50 PM | #18 |
Scooby Guru
Member#: 487
Join Date: Nov 1999
Chapter/Region:
TXIC
Location: Houston TX
Vehicle:1998 /2005 STunIcorn Acadia Green USDM 22b |
BTW James
If my cam seals leak again after my 6th T belt RI Will send you the new short Block. Of course you have to come to TX to take out motor!!!!!! ***55357;***56832;***55357;***56832;***55357;***56832;***55357;***56832;***55357;***56832;***55357;***56832;***55357;***56832;***55357;***56832;***55357;***56832;***55357;***56832;***55357;***56832; |
06-03-2020, 10:41 AM | #19 | |
Scooby Specialist
Member#: 29292
Join Date: Nov 2002
Chapter/Region:
SCIC
Location: Orange County CA
Vehicle:2004 WRX wagon silver |
Quote:
|
|
06-03-2020, 09:52 PM | #20 | |||
Scooby Guru
Member#: 51282
Join Date: Dec 2003
Chapter/Region:
SCIC
Location: Pasadena, CA
Vehicle:98 RS black & blue from parking |
Quote:
Quote:
Quote:
sure is... but at the same time something is really broken and I do want to fix it! |
|||
06-09-2020, 11:43 PM | #21 |
Scooby Guru
Member#: 487
Join Date: Nov 1999
Chapter/Region:
TXIC
Location: Houston TX
Vehicle:1998 /2005 STunIcorn Acadia Green USDM 22b |
Update Homie?
Bump |
06-10-2020, 02:32 PM | #22 |
Scooby Guru
Member#: 51282
Join Date: Dec 2003
Chapter/Region:
SCIC
Location: Pasadena, CA
Vehicle:98 RS black & blue from parking |
I actually started a new thread with just my v specific question!
https://forums.nasioc.com/forums/sho....php?t=2922790 I took the old valve out and it seems like it's in fine working order, but I did order a new one just for fun. |
06-16-2020, 01:14 AM | #23 |
Scooby Guru
Member#: 51282
Join Date: Dec 2003
Chapter/Region:
SCIC
Location: Pasadena, CA
Vehicle:98 RS black & blue from parking |
Well for everyone holding their breath at home, my new valve arrived and it works exactly the same as the old one. The drain valve appears to be normally open at rest.
Scratching my head thinking about where to go next. |
Thread Tools | |
Display Modes | |
|
|