03 Auto N/A randomly stalling on stopping.

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03bajaSport
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03 Auto N/A randomly stalling on stopping.

Post by 03bajaSport » Tue Jan 30, 2018 9:40 pm

Hey all,
Been driving my 03 for about a month or so now and over the last week or 2 it has nearly stalled or actually stalled about 5 times. All were under moderate to heavy braking and i am trying to narrow down the culprit.

At first i thought it was the ECU not retrained properly but then found out that is for the electronic throttle not my wire type.

Second thought was a vacuum leak which i haven't had time to trace.

Third was the trans may not be shifting down fast enough due to dirty fluid *i don't know when it was last changed but i am doing it this week)

Also i noticed if i blip the throttle it will do it where the rpm's drop down below the second line.

Now recent things that have been done:
Radiator, head gaskets, seals, and a new canister muffler
she has 257k on her atm

Thoughts?

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Guacamole
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Re: 03 Auto N/A randomly stalling on stopping.

Post by Guacamole » Wed Jan 31, 2018 1:45 am

Easiest thing that comes to mind is a dirty air filter. Something else is to possibly check the idle air control valve or the sensor- could be dirty or faulty.
viewtopic.php?p=18972#p18972
http://www.ultimatesubaru.org/forum/top ... n-braking/ (see posts 16, 17, & 20)
Definitely check what you've listed as well though. Worst case I'm reading it's trans-related.
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Re: 03 Auto N/A randomly stalling on stopping.

Post by kamesama980 » Wed Jan 31, 2018 10:47 am

dirty air filter will restrict top end, not stall at idle.

vacuum leaks will INCREASE rpm at idle in a speed-density system like we have.

Faulty TPS could do it. dirty throttle or idle control valve.

how old are the plugs and wires? when was the last time you checked the valves?
-Russell
"You don't get to judge me for how I fix what you break"
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05 turbo 5mt vf39 and other STI bits, 3" turbo-back

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03bajaSport
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Re: 03 Auto N/A randomly stalling on stopping.

Post by 03bajaSport » Wed Jan 31, 2018 3:43 pm

Well the plugs were OK when we had the head gaskets done last year but it was only on the road a month after that.
No clue how good the PCV/ICV are nor the TPS.
Throttle might be dirty as well.

When it warms up (the weather not the car) i may pull everything and go clean crazy. Thanks for the links and suggestions!

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Re: 03 Auto N/A randomly stalling on stopping.

Post by kamesama980 » Fri Feb 02, 2018 12:34 pm

03bajaSport wrote:
Wed Jan 31, 2018 3:43 pm
Well the plugs were OK when we had the head gaskets done last year but it was only on the road a month after that.
No clue how good the PCV/ICV are nor the TPS.
Throttle might be dirty as well.

When it warms up (the weather not the car) i may pull everything and go clean crazy. Thanks for the links and suggestions!
Not how they look, how old are they/how many miles. I've seen plugs run fine that I'm amazed it ran at all and I've seen plugs that could just about go back in the package and be sold as new (looking) that kept the engine from stalling. Same with the wires: looking crappy means they need to be changed but looking good doesn't mean they're good.
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"You don't get to judge me for how I fix what you break"
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Re: 03 Auto N/A randomly stalling on stopping.

Post by 03bajaSport » Sat Feb 03, 2018 5:35 pm

kamesama980 wrote:
Fri Feb 02, 2018 12:34 pm
03bajaSport wrote:
Wed Jan 31, 2018 3:43 pm
Well the plugs were OK when we had the head gaskets done last year but it was only on the road a month after that.
No clue how good the PCV/ICV are nor the TPS.
Throttle might be dirty as well.

When it warms up (the weather not the car) i may pull everything and go clean crazy. Thanks for the links and suggestions!
Not how they look, how old are they/how many miles. I've seen plugs run fine that I'm amazed it ran at all and I've seen plugs that could just about go back in the package and be sold as new (looking) that kept the engine from stalling. Same with the wires: looking crappy means they need to be changed but looking good doesn't mean they're good.
Valid point. Ill do a full tune up to be safe, im gonna assume as i don't have all the records for the maintenance for her that everything short of the fuel filter /oil is 257k old...lol So i maye just replace everything at once or try one at a time to narrow it down. Tough when the car isn't throwing a code.

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Re: 03 Auto N/A randomly stalling on stopping.

Post by 03bajaSport » Sun Feb 11, 2018 12:06 pm

So i have taken it off the road for the time being as its become unreliable, driving my 01 outback for the time being.

So now i cleaned the IACV the other day ran fine that day but now it has trouble starting in the morning, it basically turns over sputters then stops, unless i press the gas pedal. Eventually it finally will stay running after about 2-3 mins of keeping the idle above 2k. Then it idle's fine and will drive but if i accelerate heavy for any reason when i let off the gas it will shoot to under 500 rpm and the possibly stall.

Fuel filter? MAP Sensor? TPS?

Thoughts?

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Re: 03 Auto N/A randomly stalling on stopping.

Post by Guacamole » Sun Feb 11, 2018 3:32 pm

03bajaSport wrote:
Sun Feb 11, 2018 12:06 pm
Eventually it finally will stay running after about 2-3 mins of keeping the idle above 2k. Then it idle's fine and will drive but if i accelerate heavy for any reason when i let off the gas it will shoot to under 500 rpm and the possibly stall.
Now this sounds exactly like this issue: http://www.rs25.com/forums/f13/t185502- ... lling.html
Kamesama called it: throttle body's probably all gunked up & needs some cleaning.
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Re: 03 Auto N/A randomly stalling on stopping.

Post by 03bajaSport » Sun Feb 11, 2018 11:25 pm

Guacamole wrote:
Sun Feb 11, 2018 3:32 pm
03bajaSport wrote:
Sun Feb 11, 2018 12:06 pm
Eventually it finally will stay running after about 2-3 mins of keeping the idle above 2k. Then it idle's fine and will drive but if i accelerate heavy for any reason when i let off the gas it will shoot to under 500 rpm and the possibly stall.
Now this sounds exactly like this issue: http://www.rs25.com/forums/f13/t185502- ... lling.html
Kamesama called it: throttle body's probably all gunked up & needs some cleaning.
Yeah i think im gonna pull it tomorrow and have a good go at cleaning it, i'll keep everyone updated :)

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Re: 03 Auto N/A randomly stalling on stopping.

Post by Guacamole » Mon Feb 12, 2018 12:20 pm

Just a head's up, DO NOT disassemble the throttle body once you have it off. I've read that doing so will cause issues with the ECU & throw codes like crazy since everything in there is calibrated to a certain degree.
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Re: 03 Auto N/A randomly stalling on stopping.

Post by tomato_88 » Mon Feb 12, 2018 10:47 pm

When I purchased my 03 it idled rough. It almost felt like a vibrating chair when in gear. I pulled the throttle body off and cleaned it soon after. I could not believe the amount of build up on it. Even after a similar number of miles my other Subarus were never that dirty. I changed the PCV valve at the same time. Turns out those are supposed to have moving parts!

I hope the cleaning goes well for you.

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Re: 03 Auto N/A randomly stalling on stopping.

Post by cspaugh » Tue May 28, 2019 2:54 am

The link above sounds like the exact issue we just ran into after replacing spark plugs and timing belts. Car stalls when taking foot off gas at a stop sign or light or slowing down to park. No struggle or shaking just engine stops and cranks right back up. I will check and clean teh throttle body tonight and see what is what, first time for me so it should be fun.

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