Baja 2005 manual 4cyl. when starting engine, idle doesn't hold and engine stops. No codes or other symptoms.

[Baja-sean]

Original owner to this Subaru. Will note two fuel filters replaced by Subaru.  The first one completed 19-April-2008 at 61,281 miles driven. Second replacement was a recall for fuel pump (under warranty) the 14-Nov-2009 at 87,642 miles driven. Since those two dates, I followed up with 30K mile service; Invoice shows Inspect fuel system, connections and hoses. I notes this action noted in invoices to the year 2013. 

Currently, at 292,089 miles driven, I had a non-Subaru auto mechanic service the Baja November 2021. The mechanic "performed a Fuel Injection system service, test drove vehicle, injection system operating normally, no concerns at this time."

The idle issue is intermittent. No indication as to when it may happen. Confirming no Engine light on. The battery is new. I've learned to use neutral, and rev the engine, acceleration, just under 2k RPMs. The idle corrects its self and I move on. I normally keep the tank 1/2 full; regular gas. 

Any feedback would be appreciated, 

Sean L Douglas 

[88SubGL]

Just my opinion, but the first thing I would do is replace the fuel filter. I assume it has the external, under hood filter. According to what you wrote, it hasn’t been replaced in 200,000 miles, not even when the fuel injection service was done? It may not help your problem but it won’t hurt it.

[1 Lucky Texan]

maybe the hose from the IACV is trying to come loose.

at that mileage, throttle position sensor could have a 'dead spot' I guess.

[GeneralDisorder]

Is this a drive by wire engine or a drive by cable engine? I can never remember what the Baja got and didn't get it's such a giant sack of random parts. 

GD

[Baja-sean]

Thanks for the ideas.  I'll need to look up the location of 2005 Baja fuel filter.  I'm hoping not in the tank, but external as mentioned.  The November 2021 maintenance check did not include a fuel filter replacement. I probably needed to request that service. 

IACV - will need to research that item. I'm not a mechanic. However another area of the vehicle that may be checked out. 

Do not know the answer to, "Drive by wire engine or cable..." Another question I'd be able to ask. 

Appreciate these replies. 

Thanks, Sean

[idosubaru]

58 minutes ago, Baja-sean said:

Thanks for the ideas.  I'll need to look up the location of 2005 Baja fuel filter.  I'm hoping not in the tank, but external as mentioned.  The November 2021 maintenance check did not include a fuel filter replacement. I probably needed to request that service. 

IACV - will need to research that item. I'm not a mechanic. However another area of the vehicle that may be checked out. 

Do not know the answer to, "Drive by wire engine or cable..." Another question I'd be able to ask. 

Appreciate these replies. 

Thanks, Sean

scan for check engine codes. You could have a pending code that hasn’t tripped the check engine light yet. unlikely but it’s free and takes 2 minutes  and is a good starting point.

Do you notice any difference when warm verse cold?

How about when driving slow or letting off throttle completely or at a stop sign?

are there conditions when it’s more apparent?

Test, clean, or replace idle control.  

Check for vacuum leak like Loose intake or vacuum hoses. 

 

It’s not the fuel filter.as the prior post said they’re cheap and easy so doesn’t hurt to replace. But Subaru fuel filters routinely last the life of the vehicle, the pumps have a huge sock/screen on them, and you’ve taken good care of this vehicle. If it sat for a long time and had rust issues galore and needed lots of work then yeah maybe a rusty tank clogged the filter and your pump is trashed too. By your description that’s not you. Otherwise it’s a terrible first guess. Too many anecdotal “successes” get reported as fuel filters when it was something else and they just didn’t know it. Its such a standard low grade answer that doesn’t make any sense in the face of reality. I assume fuel filters or gas used to be trashy clog prone garbage of some bygone decade or fail all the time on other equipment for as often as I still hear them talked about even though diagnostically confirmed demonstrable *Subaru* issues are basically unheard of.

Edited December 16, 2022 by idosubaru