MY00 - Engine Reving Up+Down while trying to hold RPM - Getting undrivable
 

Hey Everyone,

I have an MY00 WRX that I just keep having problems with. It's in great condition(Engine bay looks new).

Recently I had a surging/stuttering under boost issue which Subaru and all other sources put down to the AFM. I changed that and it was the same. So I changed the practically brand new BKR6ES-11 Plugs that came with the car for PFR6B and all was Great.

Then an intermittent problem appeared, Starting mainly when taking off from stand still or down changing for a corner. The car will jolt between gear changes and then go into "Undriveable Mode" This Mode could last for a few minutes or until I turned the car off and on again- then do it again within minutes/seconds or not at all . It was so intermittent and now its gotten worse -basically getting to be all the time no matter how careful I try to drive the car.

Main problem is I can't hold a constant coasting speed - it will either just slow down or speed up - jerking between the two. For example trying to do 60km/h it will just keep creeping up, so you lift the very little throttle you have applied, and it will slow down, so you gently push the throttle again to maintain speed and there is nothing in the pedal. You hold the same pedal position then BANG - the drivetrain gets a shock as power returns. My Gear changes are disgusting in the "undriveable mode" unless you ride the clutch at a higher RPM. It's like there is no fuel when I very gently push the throttle and then it all comes in a big jerk/bang - which leads me to speed up again and on my way for a ticket. It is also embarrasing because you are always going slow/fast/slow/fast through roadworks or 60-80 zones and the cars is visibly jumping/lurching forward. It is much better at 100-110kmh but is still there.

When I push my clutch in idle drops to the first couple of lines on the Tacho(5-600rpm I assume) and hunts a little bit. When not in this "mode" it idles about 8-900rpm.

THEN!! I noticed when in this "mode", stationary or rolling at speed, in neutral I cannot hold any rpm from about 1500-3000. I goes Up/Down/Up/Down for a bit Hunting majorly then it burbles and The CEL comes on. Then If i take my foot off the throttle it goes down to 500-600rpm and the CEL goes out and idle rises a bit.

The CEL code is 24 -Idle air control Solenoid. I pulled it out and its quite clean - a bit of carbon. I think I have a fair idea how it works, but have no workshop manual for this car. I wiped it a bit and someone said to grease (why) it but I didn't and put it back in. I noticed the solenoid didnt move much in or out(1/4mm) just rotates - I assume when voltage is applied it controls the solenoid which adjusts the valve on the end to allow for closed throttle at idle, turning on a/c etc.

Now the car has never stalled (although almost when I try to hold revs at 2000 in neutral when it hunts for a while then burbles and light comes on, sound like its runnning on 3 cylinders when it burbles)

It sometimes goes in and out of this mode 5 times in a mintue, or stays like it for 30 mins, or used to go a week without doing it at all - BUT ITS GETTING SO BAD NOW:(

It feels more like a throttle position sensor problem than the Idle control solenoid. But I don't know. Ive only had car for a couple of months and it's all pretty new to me. So far all I've done is change the Radiator, Plugs(What a mission) and AFM/FIlter. The car is stock except for a 3" Hitech Exhaust(Cat back I assume) I use BP Ultimate 98 only and I don't thrash it. I just wanted a zippy daily driver.

I will test the TPS soon with a multimeter soon just to rule that out. And If I rotate the Idle control solenoid while it's installed while the engine is running it seems to affect the idle.

Is it possible the Idle control solenoid is Stuck/Sticking? Is it supposed to move without voltage? Can I apple 12 Volts to any of the Pins while out of the throttle body to see if it works?

Please is there anyone out there with any ideas? Am I damaging it by continuing to drive when it does this(Apart from clunking/wrecking the gearbox/driveline and wrecking the clutch). I tried swapping the AFM again with another but its the same.

I have searched and searched the internet and various forums and cannot really find anything similar with this hunting at 1500-3000rpm. RPM barley hunts at idle in this "mode" if at all. RPM is just lower than when the WRX is performing as it should.

Sorry for the long Post. I hope someone reads it all and can lead me in the right direction. I don't want to go to Subaru and fork out a heap for such a trivial problem.

Thanks Heaps Perth WRX Crew

Update
 

I just realised I've owned this car for 6 months!!!!!( I said a couple in my post)

I was thinking it was only a couple, Because its still so much fun to drive when it runs good - It hasn't worn off yet.:)

Always loved the GC8's from the earlier rally days, I'm a Subaru Convert Now..... Almost.

I Just want it to be like most other Cars I've owned and now own. No problems like split radiators that look brand spanking new, misfiring on new sparkplugs that a dealer serviced before I bought it from a private sale, intermittent undrivability, STUPID Alarm system(God dam Hijack Mode - Master code,sticky keypad etc). I wish I could open my door and take my seatbelt off without turing the car off(not while driving of course)

I now notice every WRX on the road and I love Em.(I am a Subuaru Convert)

I just want mine to work and be reliable.
:occasion6

TPS failing or incorrectly adjusted will do this.

But also check:
blow of valve sealing under vacuum
all vacuum lines for splits
all pre & post turbo induction hoses for splits/loose clamps.

check your throttle cable..

also, do upgrade your fuel pump to a larger one, ie walbro 255, bosch etc.. stock fuel pump might be playing up hence the intermittence as it might be sending fuel to the injectors on an inconsistent basis.

if u r running a FMIC, do check for air-leakage and ensure there's no split hoses. likewise for a tmic, do check the joiner on the throttle body to the tmic is intact

just my 2cents.

My money is on the fuel pump.....if it isnt getting the correct fuel pressure the engine will show these symptoms.

its a cheap fix (~$180) and also a necessary upgrade to the car if you are going to be pushing more power from the engine.


I would also suggest using a can of upper engine cleaner, its ~$15 from subaru and be enough for 2 goes.

Steve

[QUOTE=blommer;414042]stock [B][U]oil pump[/U][/B] might be playing up hence the intermittence as it might be sending fuel to the injectors on an inconsistent basis.

just my 2cents.[/QUOTE]

What does the OIL PUMP have to do with the fuel system?????

derrr Rosco, keep reading that same sentence! It's all explained!

[QUOTE=blommer;414042] it might be sending fuel to the injectors on an inconsistent basis.
[/QUOTE]



But seriously, i think it was just a typo.

edited.. typo lameo

I got away with driving for about 45mins today without any symptoms. Then the next 2 times I drove the car it was back.

Throttle cable is good. I've checked the vacuum hoses and I can't see anything noticable.
I've had the intercooler off and can't see/feel any noticable leaks on the intake after the AFM to the throttle body. A while ago I hooked a boost guage up and Vacuum at idle and boost seemed fine.

THe car drives fine once its pulling through a gear all the way, boost is good, no hesitation, its just I cant change without thudding the drivetrain or coast at any constant speed. Problem is in the low rev range.

Just a question. Is the idle control solenoid supposed to rotate when it is installed. It is quite loose and wobbly but the flange is tight. When the engine is running and I push and pull on the ICS I can speed up and slow revs slightly and I can rotate it 360.

Playing with it a bit seems to induce this problem. If you gently try to hold revs in neutral it seems alright to about 1500rpm then at around 2000 it goes crazy up/down then after a few loops of that it burbles like its on 3 cylinders and CEL comes on till I release the throttle and it falls back to 600rpm then CEL goes out. Then revs raise slightly.

When driving and I put the Air con on, it also makes this problem appear quicker.

It logically seems it may be TPS, I need to check the votages. But the ICS - I'm hoping it's not suppose to rotate/move like that, but it looks like that was the way it was designed and it has been like that since day one.

As we all know it sucks to keep throwing parts at cars/machines with hope each new part will fix it and it never does. In my experiences it seems that's what a lot of crap mechanics do and charge you $1,000's for the previlidge.

I'm hoping someone has had the exact same problem and can nail it on the head.

Thanks

No, nothing on the outside should be able to move, the body is supposed to be fixed to the flange.

How did it get broken? Someoene smack it with something?

The only part that should move is the valve piston (black tapered piece on the right in this photo).
[IMG]http://i16.ebayimg.com/05/i/001/2f/92/5872_12.JPG[/IMG]

It's been like it since I had it. Mine says a33-660-r00 but looks exactly the same.

Another Question, Should I be able to push the valve in when out of the car. Is it supposed to be spring loaded or anything. At the Moment it doesn't really move,but I assume it doesn't have to move much. Is there any way to test the operation of it out of the car?

Is it supposed to be pressed into the flange? Maybe I can press/secure it back in for now, reset the ECU and then source a new one.

Hopefully not too expensive.

Great, I feel like I'm getting somewhere.

No you can't just push it back afaik...it's a stepper motor with about 20 steps from fully closed to fully open.

It's the plug end that's loose on yours is it? That's what I'm gathering from your posts.

Here's how to test it:

An IAC motor can fail one of two ways, either the motor short circuits and stops working or the motor will develop high resistance and cause the IAC control motor to react slowly, either failure can cause the engine to stall at idle. When a trouble code scan is performed it sometimes won't always detect a failed or weak IAC motor.

To check the IAC motor remove the unit, with the wires connected turn the key to the "on" position without starting the engine, the IAC should move in or out.

If the IAC motor does nothing it has probably failed, replace it with a new unit and recheck the system.

Note: whilst the IAC motor is removed clean (use aerosol carburetor/ throttle body cleaner) the passages the IAC uses to control idle air speed, also inspect the IAC for a build-up on the seating (pointed) end and clean as necessary.

Thanks Heaps,

I'll Test it after work. I heard they are expensive for something so small.

Its all starting to make sense now.

The valve seat looks clean, but I'll still grab some upper engine cleaner from Subaru.

:)

Changed the IACV. Seemed much better at first.

I will keep troubleshooting when got the time.

My IACV was loose as in the mounting, but didn't seem to have affected my idle too much at the time in comparison to the new one.

(mind you the one I put in is still 2nd hand but symptoms are the same as before)

Afm!

AFM for sure, mine behaved very similarly on one of the occassions where the afm died.

..... umm yep, 'cept he said he replaced the AFM in his 1st post :icon_conf

Not AFM
 

I Have a brand new AFM and I have tried swapping the two several times and there is no difference.

I also tried resetting the ECU by plugging together the black and green connectors, then holding the throttle Full then Half, but I cant get an ECU reset.
I do get a different code while driving after a minute - 32(O2 sensor?) but the car is driving fine at the time. When I use the black read connectors though I only get the code 24 (Idle Solenoid) and no code 32.

I have a feeling the Idle solenoid I got is stuffed. It gets really hot even if the throttle body is quite cold at startup. With it removed from the throttle body it moves in and out on ignition on/off. I did this a few times in a row and the valve stem flew out and almost lost the spring. Is this supposed to happen? It's never stalled and always starts straight away.

I reckon this 2nd hand one I scored for stuff all is broken and is too slow/too much resistance hence the heat - or is this normal. But Bunbury Subaru want $900.00 for a brand new one - WTF!!

Anyone got a good 2nd hand one they want to sell or I'll have to check the wreckers. Otherwise I may look into this O2 sensor (Even though Im sure its the Idle solenoid)

Turning on the A/C makes this undriveable mode occur alamost instantly although sometimes I can drive for ages without it occuring with AC. Its really only at low speeds/throttle when it begins and then stays.

I don't know its so intermittent its annoying. I may have to bite the bullet and go to Subaru so they can play - but $900.00 for such a tiny motor/solenoid is what scares me away in the first place and it might not even be the cause - just a code and then they throw parts.

I bought this car as a reliable fun daily driver, but its been quite the opposite (except for the fun bit) and the price of parts is insane.

Please stop me - you have 30 mins
 

Ok I have another IACV on the way.

In the mean time due to the 32 code while driving in diagnostic, I have a new "Champion (WTF) O2 sensor"

I removed the old one quite easily, And the new one is a different plug.

I was told Bosch over the phone, but when I got to Repco I landed myself a Champion O2 sensor that there is NO information on the internet at all.

I asked for a 3 wire - my00 2000 Subaru Impreze wrx O2 sensor. This is what they gave me (even after quoting bosch from the system)

I cannot find anything on the internet - and I have already removed old sensor, cut wires and I am ready to join and re-install. Now - Do I solder (Temp for stainless) or just crimp/ heatshrink. Should I even be using this Sensor (World First IT seems).

All I want is a WRX that works like for everyone else. I don't flogg it - just every now and then I want some boost - apart from that a "DRIVEABLE CAR"(Which it is not....)

PLEASE HELP ME _ I SEE WRX'S EVERYWHERE AND THEY ALL WORK GOOD. (ANd F**K you Subaru dealerships, you remind me Of Seadoo. I Don't see Holden and Ford fans Bitchin' their dealerships....)

[QUOTE=VETTETOREX;420273]Ok I have another IACV on the way.

In the mean time due to the 32 code while driving in diagnostic, I have a new "Champion (WTF) O2 sensor"

I removed the old one quite easily, And the new one is a different plug.

I was told Bosch over the phone, but when I got to Repco I landed myself a Champion O2 sensor that there is NO information on the internet at all.

I asked for a 3 wire - my00 2000 Subaru Impreze wrx O2 sensor. This is what they gave me (even after quoting bosch from the system)

I cannot find anything on the internet - and I have already removed old sensor, cut wires and I am ready to join and re-install. Now - Do I solder (Temp for stainless) or just crimp/ heatshrink. Should I even be using this Sensor (World First IT seems).

All I want is a WRX that works like for everyone else. I don't flogg it - just every now and then I want some boost - apart from that a "DRIVEABLE CAR"(Which it is not....)

PLEASE HELP ME _ I SEE WRX'S EVERYWHERE AND THEY ALL WORK GOOD. (ANd F**K you Subaru dealerships, you remind me Of Seadoo. I Don't see Holden and Ford fans Bitchin' their dealerships....)[/QUOTE]

Bite bullet... you want nice smooth driveable car... Ring ASG...Book car in...Wait....Drive and smile.

Changed the O2 sensor and the code doesn't appear in Diagnositc mode anymore.

But the car drives exactly the same.:(

[QUOTE=VETTETOREX;420348]Changed the O2 sensor and the code doesn't appear in Diagnositc mode anymore.

But the car drives exactly the same.:([/QUOTE]

Like people have said....take it to a workshop...there are a number of reputable ones in Perth including Maximum Motorsport and All Star Garage plus Leigh Hynes/RMS in Busselton. It appears that you've wasted a month of your time trying to fix it yourself via the internet.

Nah not a month just a few hours here and there. Spent more time writing the posts hehe.

Such a simple problem I thought. It sux hows it perfect one minute then screwed the next. Ohh well. Get to the bottom of it soon.

Sigh.....
(First post on this 5/12/09....today 6/1/10)

Hey Unders
If you want to get it looked at but dont want to go to perth give Leigh Hynes @ RMS a call, he is from perth but has set up down in busselton as well, he is a subaru specialist, knows his stuff and has a mobile service

[url]http://revlimitms.com.au/index.php?option=com_content&task=view&id=5&Itemid=47[/url]

Im wondering if you have an intermittent brant problem (dry solder joints at the fuel pump relays causing a fuel cut) its common and causes similar symptoms

You did check for vacuum leaks on all intake hoses didnt you, including under the intercooler
those subaru techies are renound for leaving clamps loose

FIXED

Got my new IACV (From Wangara wreckers)(3rd one)

I have done a good drive and Not a Problem yet....

The other two IACV's were obviously stuffed. This new one put in and not a problem.

They both moved when the key was on but obviously they were slow/laggy.

I can't believe that one little plunger had so much effect on drivability out of idle. The car never stalled or got close.

I'm Stoked. I hope it stays that way.

Thanks for all your help.

At the end Of the day It might have taken a month but I still saved a SHIT load of Money.

Thanks Guys.