Jump to content
Ultimate Subaru Message Board

hard to start, runs rough immediately after getting gas..


Recommended Posts

2004 Forester - EJ251, manual..

this has happened the last two times i have put gas in.. get gas, and the engine is difficult to start, and runs roughly for a minute or so once it is started. Once it settles in and runs nice, it is fine.. no more starting issues, no more rough running until i get gas again...

is 2004 one of the ones that had the fuel pump cap issues? could this be a symptom?

Link to comment
Share on other sites

Dunno about the cap issue but try starting with your foot flat to the floor and see if that gets it started. 

This cuts the injector pulses off during cranking, and if the trick works something is causing a flooded engine event. 

Cheers 

Bennie

  • Like 1
Link to comment
Share on other sites

i did have to hit the gas pedal to get it to start yesterday, then had to hold it about 1/3-1/2 to keep it running until it straightened up.

 

not sure if it matters or not, but both times gas level in the tank was around the 1/4 tank mark...

Edited by heartless
Link to comment
Share on other sites

the cap/o-ring problem is not too bad to inspect for, I just dunno if the Forester's design is similar.

I may not know exactly what the issue is here - but can't help wondering a coupla things;

suppose the input of fuel is disturbing some debris in the tank that collects on the 'sock' - but temporarily ????

any whooshing of air when the gas cap is loosened/removed? and sense if air is moving in or out?

I'd be tempted to try 2-3 tankfuls with Techron (maybe seafoam?) or similar gas treatment, maybe some odd check valve is sticking somewhere????

maybe scan the ECU and see if a code is pending?

Link to comment
Share on other sites

Sticky IACV comes to mind but the occurrence when filling with fuel does not as this issue doesn’t discriminate with fuel levels… 

Haven’t changed or played any plumbing under the bonnet recently? I’m wondering if it could be some fuel being pushed through the vac lines or an emissions venting system that’s potentially flooding the engine. Mind you I can fill all of our Subarus to the brim and none have an issue with starting afterwards. 

It’ll be interesting to know what the issue is once it’s sorted! 

Cheers 

Bennie

Link to comment
Share on other sites

have not messed with anything underhood recently.

slight air movement when popping the fuel cap, and it does "lock" like it is supposed to

i kind of wondered the same about possible grunge, but it is just odd that it started suddenly

 

Link to comment
Share on other sites

44 minutes ago, lmdew said:

Brothers 99 Legacy with a 2.2 installed is doing the same thing.  No CEL.  Runs fine otherwise.  Strange.

did his start acting like this suddenly as well?

next time i get gas i am going to try something... rather than locking the handle (lowest position), i am going to run it a bit slower, see if that makes any difference

have never had a car do this before, so quite puzzled

Link to comment
Share on other sites

try a squirt of starting fluid immediately - when it's running rough? at least we'd know if it was fuel-related...?

 

or, next time you feel it would fail,  do a few OFF to ON (not START) key cycles. wait for a 3 count at ON, then go to OFF, back to ON, 3 count, etc. - quickly. That runs the fuel pump and should fully pressurize the rails....?

 

you said you can detect a little air movement...wonder what would happen NOT at fueling, but say right now you removed and replaced the gas cap? would it start smoothly?

 

Edited by 1 Lucky Texan
  • Like 3
Link to comment
Share on other sites

5 hours ago, 1 Lucky Texan said:

..wonder what would happen NOT at fueling, but say right now you removed and replaced the gas cap? would it start smoothly?

interesting thought.. will have to give it a try & see what happens

 

Link to comment
Share on other sites

lol, not like I know what any of the results would mean....

 

between the purge valve and the evap 'drain' valve (connected to the carbon canister) the fuel tank should not have any pressure differential with ambient air so, I think the air moving effect you get when removing the cap 'could' be a clue....?

Link to comment
Share on other sites

The purge valve was a common issue in the early turbos - a mate of mine recommended that I move the purge control valve from under the intake manifold to somewhere easily accessible for replacement. 

So I’d agree that this could be the issue on both vehicles mentioned in this thread. Good thought @1 Lucky Texan!

Cheers 

Bennie

Link to comment
Share on other sites

And I always fill until the brim because extra fuel in the tank - more time away from the servo for me, plus it’s the most accurate way to keep fuel records knowing the tank is full to the same level every time. 

I’ve not had an issue with this method of filling in my brumby, L series or my sister’s Gen3 Liberty. And it’s not like I’m only driving a block or two before the car is shut off and left to sit.

Cheers 

Bennie

Link to comment
Share on other sites

19 hours ago, heartless said:

evap canister, sure, but this is not a turbo model, just an NA, so is a purge valve even on my car? if so, where would it be located?

and i dont "top off" when i get gas, pump until it kicks off, and done.

I think your car should have a purge valve.  Look it up on Subaru website or ebay or image search.  It'll be on the intake manifold or possibly the evap canister. 

  • Like 1
Link to comment
Share on other sites

pouring down rain with tornado watch right now, so poking around will have to wait

i did try loosening the fuel cap before leaving the house today (no air hiss, either), and it started just fine, but that was on a cold start... want to try it again with warm engine... would have done today, but like i said.. rain. =P

aside from this issue (only a problem when getting gas), the car runs perfectly - every start outside of getting gas is fine, no problems, starts right up, idles fine, drives fine - no issues at all otherwise.

have been driving this car since September with no problems until it suddenly started this weird thing at fill ups.   just strange...

Link to comment
Share on other sites

all good, thanks, Bennie.
watch just means to be prepared, conditions are right for possible tornadoes - warning is when a funnel cloud has been spotted and it is time to take cover.

had been really hot on Tuesday, then a cold front moved in, producing thunderstorms... perfect weather for a tornado... hot air mixing with cold, strong winds, etc

Link to comment
Share on other sites

ok, tested opening the cap with everything fully warmed up... no air sucking, no problem re-starting

partner offered to top up the tank since we had to get gas for the lawn mower as well... was about half a tank at the time...  interestingly enough, no problem starting that time.

the previous 2 fills, with the starting issue, happened when around a 1/4 tank left ... so... how much is left in the tank when filling seems to be a factor..

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...