Idle? help!
 

hi all just cleaned out my throttle body and replaced my vacuum pipes and now when i start it, it goes to about 3K rpm then after acouple of secs drops to 2.5K rpm then straight away goes to 1.5K rpm with the engine check light on. with the maf sensor unpluged it just consantly idles at 1.5K rpm with the engine check light on. i know my throttle needs ajusting does my ecu need restting aswell?

any info would be a great help.

Sounds like a knackered MAF to me. If you unplug a fully working MAF then the engine should stall. It sounds like the ECU has taken over the MAF's job. You could try a reset, however, it does sound like the MAF to me.

also just to add when i rev it it will hold the rpm revved to for a couple of seconds then very slowly decrease.

managed to get it to idle at 1K rpm now with the maf pluged in it revs to 2K rpm and when the engine check light comes on it drops to 1K rpm, light goes out and goes back to 2K rpm?

ok i think ive found what it is, the air control solinoid valve, i unplugged it and everything went back to normal, (apart from high idle but i think the throttle just needs ajusting for that) rev it and straight away the revs drop again.

i think this is my fault as i took the valve off the top to clean the thing that bolts to the inlet manifold, has anyone got any pics of the gap it should hav inside it so i can try ajusting it or just get a new one?

right i think im out of ideas ill hav to wait til my other one arrives i took the icv off and noticed that the rubber ring inside was missin found it under the inlet, put it in and the icv back on and still doin it so if anyone has any ideas it would be a great help be people dont seen to interested.

put everything back in and then reset the ecu sometimes if the iscv was playing up the ecu remembers and even though u have fixed it its not that clever and the ecu reset is a good place to start

right ive reset the ecu and its still is doing it ive posted a video so people know exacty wat is happening.

YouTube - subaru idle

you need to check your error codes under the steering wheel behind the dash panel is a green and a black plug if never used before they'l be taped up in there somewhere,
taken from polar performance site Frequently Asked Questions

Turn ignition OFF.
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Connect black connectors under steering column.
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Turn ignition ON (Engine OFF).
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Engine Check lamp turns on.
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Any codes are indicated by a flashing lamp.
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If Code is OK then Turn ignition OFF & Disconnect Connectors.
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Turn ignition OFF & Disconnect Connectors.
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If there is a fault code check in the table below to see which sensor the code pertains to:

Reading the code: The long pulses (1.3 Seconds) indicate Tens and the short pulses (0.2 Seconds) indicate ones. Pulses are separated by Short Pauses (0.2 Seconds), multiple codes are separated by a Long Pause (1.8 Seconds). The codes are cycled.

11 Crankshaft position sensor

12 Starter switch

13 Camshaft position sensor

21 Engine coolant temperature sensor

22 Knock sensor

23 Mass air flow sensor

24 Idle air control solenoid

31 Throttle position sensor

32 Oxygen sensor

33 Vehicle speed sensor

35 Purge control solenoid valve

42 Idle switch

44 Wastegate control solenoid valve

45 Pressure sensor

51 Neutral position switch

i havent got any fault codes but if i take the beige top off the icv and twist the spindle should it spring back?

have you checked? your check engine light comes on which means you should have a fault code to check? just doing a reset doesnt fix it as the code will come right back as soon as you start it up

oh ye sorry thought it was only if the engine was running soz, ye i get fault code 24, so do i need to replace the icv as i do have another on its way and should be here tuesday?

yep code 24 is icv.....sounds like it does need replacing

one last thing check the hose that comes of the icv all the way back to the resonator box for leaks..... listened on your vid and im not sure if i can hear some air movement in there when your over the engine a leak could cause same fault and fluctuating idle

hi fixed it lol i put the beige top on backwarks what a dumb arse i am lol just need to reset the ecu now and all should be dandy.