Jump to content
Ultimate Subaru Message Board

Recommended Posts

Hi All,

Been lurking for awhile now and thought i'd finally do some posting. I have a small problem that just won't seem to go away....

 

What I have:

99 Legacy Outback 2.5l jdm swapped motor

950 CCA Battery (Napa Emergency Vehicle Battery)

Premium fuel

 

Problem:

Hard starting on cold mornings. If it's 40 degF it'll start after about 10 sec of cranking and finally catch then idle just fine and it's never an issue again. It's just the initial start. At 5 degF it cranked for about 25 sec and wasn't sure if it'd catch but it eventually did and then ran fine. Started fine for the rest of the day but it was relatively warm. The car runs fine once it's started.

 

What I know and have thought:

1) Eng Temp Sensor: replaced and didn't change anything

2) Fuel bleeding back into tank somehow.

a) fuel pressure is 40-42 psi with ig on

B) Engine running: fuel pressure is 37 psi w/ press reg vac line disconnected (4 less than range in FSM)

c) Engine running: fuel pressure is 32 w/ press reg vac line connected (+2 of FSM)

d) fuel pressure drops to 20psi after sitting for about 15 min, and further if sits longer

 

Codes:

P0130, P0500, P1101, P1121, P1540

 

Questions:

1) would those out of spec pressures contribute to this problem. I'd hate to sink $200 into a new fuel pump/pressure regulator to find it doesn't do anything.

2) should the pressure be maintained after the car is shut off indicating a faulty check valve or is this normal. if so, could installing an inline check up by the tank solve the problem?

 

Any ideas what might be creating this problem would be really helpful. I hate to take it to the dealer because they'll say it runs just fine and won't actually wait for it to get cold enough to be a problem.

 

Thanks in advance,

Mike

Link to comment
Share on other sites

Hi,

The only thing I can contribute is that the fuel pressure seems normal and the fact that it's begining to go down after 15 min. is also normal.

I have a fuel pressure gauge on my car and the same thing has been happening since the beginning without ill effects.

P0130 has to do with the front O2 sensor and P0500 with the speed sensor. I don't see how a problem with these could produce the symptoms you're having. I dont know about the other codes.

Good luck and wait for further help.

Link to comment
Share on other sites

a question, where is the fuel pressure measured-before or after the fuel filter?

 

kinda sounds like a vacuum leak or too lean (good ole not enough choke on a cold engine like).

 

how about cranking it for a couple seconds and stopping and then trying it again, instead of trying to start it from one long try?

Link to comment
Share on other sites

Hi All,

 

 

Codes:

P0130, P0500, P1101, P1121, P1540

 

Thanks in advance,

Mike

 

130 - front 02 snesor circuit malfunction

500 - vehical speed sensor malfunction

1101 - neutral saftey switch high m/t

1121 - neutral position switch high m/t

1540 - vehical speed sensor 2 malfunction

 

did you hit or runover something?

 

Cold start issue - what is the fuel pressure when the car is first cranked and stone cold? You have multiple issues here. Get a used fuel pressure regulator, but i want to know what the gauge reads after a cold overnight soak.

 

nipper

Link to comment
Share on other sites

thanks for all the quick replies.

i'm at work until tomorrow morning at which point i'll check the pressure after tonights last drive (about a 12 hr sit w/o running).

 

I have the pressure gauge post filter at this point but could easily move it pre filter. There are no signs of filter restriction in the way it drives making me think the filter wouldn't reduce the pressure but who knows how finicky these soobs are....

 

I'm also going to try the ECU reset tomorrow via pulling the battery leads off and letting it sit for an hour or so. We'll see what that does. I did clear the codes via my scanner but they came back once i started the car again....

 

thanks again,

mike

Link to comment
Share on other sites

And there is your answer.

 

nipper

 

If you care to Nipper, I'd like to understand your diagnostic here.

How would the fact that his fuel pressure goes down to zero in two hours affect the starting hability of his car. Mine has always taken about the same time, maybe a little longer, to go down to nil and I have no starting problem.

Moreover, his fuel pressure with ignition on and with engine running seems, to me at least, sufficiently close to spec to have no adverse effect on starting.

What am I missing?

Thanks in advance for your answer.

Link to comment
Share on other sites

Thats where i would go next, if it was my car, He can have a leaking fuel pressure regulator that takes extra long to build pressure back up.

 

Lets do another Regulator test. Detach the vacumum hose from the regulator and watch the gauge. The fuel pressure should go up considerablly. If it doesnt go up check the vacuum to the regulator with a gauge.

 

Leak down is normal, but your not complaining of a cold start issue which sounds like to me his regulator is lazy and taking a while to allow pressure to build back up. Another test would be to pinch off the return line and look for a quick rise in fuel pressure, as this would rule out the fuel pump.

 

One other thing to look at, and i know its awfully cold to do this, is a compression test.

 

I forget have plugs been changed on this car?

 

nipper

Link to comment
Share on other sites

thanks for the responses once again,

here's more:

 

went out after an hour and hooked everything back up. Fuel pressure at 0, went up to 42 upon ignition on. Cycled ignition a couple of times. Started like always, 5 sec of cranking, catches a bit then finally idles well. turned off. Started again, less cranking and idles well. turned off. Started again, less cranking...and so forth. Did this 5 times and by the final time the car was starting in a second or so. Starting to make me lean toward fuel pressure issues?

 

While idling if i pull off the vac hose the pressure rises immediately and drops as soon as i hook it up, no delay what so ever. Normal?

 

Plugs were changed about 10,000 miles ago with the motor install and i'm guessing they were the fancy ones since the p.o.'s receipt shows $51.80 for the 4.

 

-mike

Link to comment
Share on other sites

i'll give it a shot tomorrow morning. thanks for all the help.

i have an appointment at the dealer in the morning but the car will be warm by then, do you think they'll be able determine anything that we haven't discussed here with their computers?

 

mike

 

No your going to have to leave it with them and see it for themselves. They will hook up the Select monitor and fuel pressure gauges in the morning and will be able to see it better then us making educated guesses over the net.

 

nipper

Link to comment
Share on other sites

well i feel like a potentially big idiot right now. on my list of simple things to check was the green service connector. well, forgot to check it and did all the other stuff only to have the dealer find out it was connected. The CEL is also burned out, hence no flashing CEL to make me wonder if it was connected or not. i sure hope the po didn't remove the cel because they didn't know about the service connector.

 

anyway, we'll see what it does in the morning for cold start and see if any codes are present then if the problem isn't gone away by then....

 

i'll keep you posted,

m

Link to comment
Share on other sites

  • 1 year later...
  • 2 weeks later...

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...