[freespaz]

Hi! Newb here, and I just got this forester 2 days ago, drove it home Saturday, didn't leave the house sunday then drove over 100 miles today (monday). It was a kind of rough start this morning but ran fine, no issues at all then on my way home this evening I was less than 3 blocks from the house, waiting at an intersection to turn when it stalled. Started up after the second crank and made it home. NOW an hour later it won't stay running. It has just about 165k on it, and NO dummy lights what so ever. I also live in the middle of nowhere, I can get to an auto zone tomorrow, but I don't know what in the ever loving cheese is going on. I thought alternator, but after googling I have seen everything from the mass air flow sensor to the transmission. If I keep my foot on the gas, it will stay running but no idle, it just falls flat. Any advice or info will be greatly appreciated. Uh, the engine oil level is fine, the coolant was low, but I topped that off, and I haven't checked the trans oil, it is an automatic.

PLEASE HELP!

 

[Remco]

If I had to shoot that one from the hip, I'd look at the Idle Air Control (IAC) and air leaks first. I wouldn't just replace the IAC, tho. Replacing parts without evidence gets expensive quickly.
Look at vacuum lines and see whether any are cracked or split.
Do you have any diagnostic tools, like an OBD2 reader, multimeter, etc?

 

[freespaz]

@Remco I do not have any diagnostic tools, but there is an autozone like six miles from me. I will check for leaks in the morning, regrettably its dark now thank you so much for the reply and I will update as soon as I know. Also, even though there is no check engine light or anything could there still be codes?

 

[Sackett]

@freespaz I would focus on broken or disconnected vacuum lines.

Sent from my SM-N975U1 using Tapatalk

 

[Remco]

I do not have any diagnostic tools, but there is an autozone like six miles from me. I will check for leaks in the morning, regrettably its dark now thank you so much for the reply and I will update as soon as I know. Also, even though there is no check engine light or anything could there still be codes?

It could have stored codes but a proper OBD2 tool does a lot more than reading codes: it lets you see what that engine is doing. It requires a bit of know-how, though. I encourage anyone with an older car to learn how to use a tool like that. Even if you do not intend to repair it yourself, it is always a good idea to be informed.

One inexpensive thing you could try is this: This requires two people and a can of WD40. Open the hood. Start the car and get it to idle steadily by having one person putting his/her foot on the gas. The person not running the gas pedal spritzes a bit of WD40 around vacuum hoses. You don't have to hose the area down - just a spritz. Use it around nipples and rubber hoses. Also see what it does when you spray a bit around that bit fat plastic hose that runs from the passenger front to your air filter into near the middle of the engine towards the firewall - that's the air intake. Don't spray it at the air intake's input - near the radiator - because that will give you a false positive. Spray it around connections, etc. Note whether the engine speed briefly picks up or changes. Once you see that happen, you've likely found your vacuum leak. Inspect that area for cracks or open hoses. Often a vacuum leak will generate a code but you haven't really been driving this. Engine codes are usually thrown after you've been driving (it is called "drive cycles") so that's why you probably don't have your CEL light on.

This is what this does:
WD40 is flammable. When it gets sucked in through a broken vacuum line, it finds its way to the cylinder heads, which ignites it and thus makes it pick up speed briefly.

 

[trajik78]

possibly evap system?

 

[freespaz]

UPDATE# RAR! Thank you for all the help. So it was the main air line... uhh... coming from the air filter, the hose clamp was soo loose I could spin it. So I tightened that down, and now there is a gap in the air filter box, like both sides refuse to fix together. It is running, but its idling way fast (like 1200 instead of its normal 800) is that because its still pulling too much air from around the air filter? And to second that question should that main hose coming off the air filter box fit all the way back to the lip or should it be kind of crooked? Because if I tighten it down crooked then the box seals better, if I put the hose where it 'should' go the box won't seal.

 

[freespaz]

@freespaz I would focus on broken or disconnected vacuum lines.

Sent from my SM-N975U1 using Tapatalk

Thank you, that's what it was!

 

[2.5x_sleeper]

@freespaz the ECM should eventually relearn, but if you want to speed up the process, you could try this:

(All Years) - How to Idle Re-Learn after Battery Disconnect

Posting here as this seems to affect some Forester and Imprezza models with Electronic Throttle Bodies or IACV that undergo a battery disconnect, and lose their idle calibration. As per these links to retrain the ECU idle parameters: https://forums.nasioc.com/forums/showthread.php?t=2382568...

www.subaruforester.org

Bobby...

['07 FSXT Member Journal] ['03 X Member Journal]

 

[Remco]

UPDATE# RAR! Thank you for all the help. So it was the main air line... uhh... coming from the air filter, the hose clamp was soo loose I could spin it. So I tightened that down, and now there is a gap in the air filter box, like both sides refuse to fix together. It is running, but its idling way fast (like 1200 instead of its normal 800) is that because its still pulling too much air from around the air filter? And to second that question should that main hose coming off the air filter box fit all the way back to the lip or should it be kind of crooked? Because if I tighten it down crooked then the box seals better, if I put the hose where it 'should' go the box won't seal.

Good. You saved yourself some money.
@2.5x_sleeper is right: it likely needs to relearn settings, like your throttle, etc. Sometimes, after something has been wrong with the setup of the car, it is in your interest to pull the pull the battery terminal, wait a bit, reconnect it and start it.
After that procedure, it may initially be difficult to start and will run like crap but after about 10 minutes it will run normally again. It is a Subaru thing.

That air filter box should seal well. Before the air or even at the air filter will not cause the car to necessarily run like crap: the air taken in is measured by the computer just beyond that point so any 'rogue air' won't make a difference, from that point of view.
Still try to get it to seal, tho. You don't want so suck up road dust into your air intake - that would be equally bad.
If you get stuck, post a picture of your situation.

 

[freespaz]

Good. You saved yourself some money.
@2.5x_sleeper is right: it likely needs to relearn settings, like your throttle, etc. Sometimes, after something has been wrong with the setup of the car, it is in your interest to pull the pull the battery terminal, wait a bit, reconnect it and start it.
After that procedure, it may initially be difficult to start and will run like crap but after about 10 minutes it will run normally again. It is a Subaru thing.

That air filter box should seal well. Before the air or even at the air filter will not cause the car to necessarily run like crap: the air taken in is measured by the computer just beyond that point so any 'rogue air' won't make a difference, from that point of view.
Still try to get it to seal, tho. You don't want so suck up road dust into your air intake - that would be equally bad.
If you get stuck, post a picture of your situation.

I am waiting on help to drop by so I can have an extra set of hands to seal it. After that I'll try to pull the battery (I need to clean the terminals anyway) and see how it goes. Thank you all again for the help and will update if it starts acting normal. I've never owned a Subaru before, so the past 24 hours have been a google/learning frenzy. Like the insanely low idle speed scared me. The car I had just a week ago (2013 Hyundai elantra) sat at like 1k when at normal temp. Also, super dumb stupid question but why or what is the thought process behind NOT having an engine temp gauge? Like, I had to google what the blue temp light meant... And I'm assuming there is a red one if you're over heating?