Help with erratic idling Engine Swap?

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fozzah
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Joined: Sun Sep 23, 2018 4:43 pm

Help with erratic idling Engine Swap?

Post by fozzah » Sun Sep 23, 2018 4:51 pm

Hi all, would really love some advice with an engine swap that hasn't gone to well...:/
Ok so the recipient vehicle is an AUTO 01/03 X Forester - the donor 'engine' came from an AUTO 12/04 XS, and from the onset, when in gear [forward or reverse] if you give it a bit of gas - then take your foot of the pedal immediately - the car still idles as if your foot remains slightly on (1100rpm or so for roughly 12seconds, before falling back down to a regular idle of 800rpm after an additional 3 seconds.
Is there anything between the transmission and motor ('sensors/electrical communications' wise) that could be causing this - considering the fact it's not the original engine?
Please note after experiencing this issue, I have since swapped from the old engine to new:
-MAP/Boost Sensor
-TPS
…which has not changed the behaviour whatsoever.
Where else should I be looking guys - the throttle body itself? Would really appreciate some help - as I've run out of ideas.
Many thanks in advance, cheers Peter

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AndrewT
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Location: WA
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Re: Help with erratic idling Engine Swap?

Post by AndrewT » Mon Sep 24, 2018 3:47 pm

checked for vacuum leaks?

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Subyroo
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Joined: Mon Nov 14, 2005 10:00 am
Location: Sunshine Coast

Re: Help with erratic idling Engine Swap?

Post by Subyroo » Tue Sep 25, 2018 8:58 pm

I had a similar problem with my 2003 XS Forester, but my Suby was a 5MT. The problem with mine turned out to be the Neutral Switch.
Mine would also idle at around the 1200 RPM mark when stopping at traffic lights or STOP signs etc., it annoyed the crap out of me until Boxer Service in Brendale Qld solved the problem for me.

Now whether there is a corresponding switch on an Auto is beyond my knowledge, but maybe something to look into.

Good Luck!

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