strange idle issue

[hendy]

After a weeks worth of a headache with my car its time to seek some outside help with my 93 Legacy. EJ22 non turbo.

Issue started last Friday morning, shut the car off running fine minus an odd noise. Went to leave that afternoon and it would start and run but made a horrible noise, first suspect was timing. Deconstructed the car enough to get to the timing and found my idler pulley (the toothed one) laying there with the inner parts completely gone. The issue happened once before but was the bolt in the tensioner pulley broke off not allowing the car to run. Replaced all idler and the tensioner pulleys. Reset the timing to where its all supposed to be from what I done with prior situation (mark on crank aligned with notch above the gear, both cam gears aligned with notch in cover...the marks on outside, not the arrows). Round one I got ahead of myself and it fell out of alignment putting belt on and released the actuator before I caught it. Round two was the same. Round 3 I thought was dead on, even double checked before releasing actuator. Started her up and she ran like half the engine was dead, pouring smoke from the exhaust that smelled like straight fuel, so this lead to round 4 today.
Redone the timing, all marks set on crank and cam gears, all marks on belt aligned, released tensioner and everything stayed the same. Put the rest of what was removed in and started. Ran with a slight miss and once the engine warmed up it stumbled and stalled. Replaced plugs and wires, all 4 plugs were completely black, wires looked nasty so figured I might as well hit them too. Still stumbles and stalls, check engine light on below ~1500rpm (code flashed out as 22, knock sensor). Above 1300-1400 runs smooth at very light throttle so I adjusted set screw to makeshift an idle for time being at 1200 but stalls as soon as its in any gear. Also the marks on the timing belt seem to have moved away from the set point (cam and crank all still align to proper set points) but no smoke, only a slight rich smell in the exhaust and no power when it does move and a sputter. Can anyone point me to something I am overlooking or need to troubleshoot? Could the actuator be the culprit causing the belt to skip and create these conditions?

[Legacy777]

How many miles are on the engine & tensioner? If you've got over 100k on that tensioner, it would be a good idea to replace it. Other thing to note or ask....when you adjust the tensioner, do you use a large screwdriver or pry bar to move it over to the left all the way before tightening it down? If not, you should do this.

Also, did you replace the timing belt or reuse the existing one? If you reused it, how many miles are on the belt? I think you said you used the mark on the back of the crank gear, but I just wanted to confirm that.

Other thing to note is that I recommend rotating the engine by hand a half rotation or so clockwise and counterclockwise. This will allow the tensioner to pick up the slack in the belt before the engine fires up and minimizes the chance of the belt jumping a tooth.

I don't recommend adjusting the idle stop screws. Once you start adjusting them, the throttle bodies are never quite right, and it affects the TPS and where the idle on/off position is. When you fix the issue and the car is running properly, I suggest trying to put the stop screw back to where it was, and verifying the idle switch is adjusted properly with these instructions.

http://www.main.experiencetherave.com/s ... sting3.jpg


Lastly, you can try using those spring clamps to help keep the belt on the cam gear and everything aligned properly while you make all the final adjustments and tensioner tightening. It works well.

Here's a pic of what I'm talking about.

[hendy]

The engine is in the 15x,xxx range, don't remember exact off the top of my head. I did push the tensioner all the way left and tightened down in that position. I did install a new belt, the old one was absolute s***. I used the mark on the outside of the gear, not the triangular notch or notch on the teeth on the rear of the gear. The tensioner is my next suspect because its history is unknown but takes a minimum of 6 days to get one here according to the parts stores. Any suggestions where to find a good price and quick shipping on one?
The throttle stop I knew wasn't a bright idea to move but working solo and needing an idle to observe the engine, it worked. It was marked and threads counted to ensure it returns to the original position. I will try the clamp trick as soon as I can get everything back apart.

[subytech]

I get my tensioners from napa cuz they are literally the same as the OEM subaru one it just dosn't have the fuji logo on it and its WAY cheaper.

Also your marks on the timingbelt itself only line up every couple HUNDRED revolutions because the gears don't have a straight 1:1 rotational ratio with the pully's so no worries there. Like you already said as long as your marks on the pullies are good with the marks on the block, cyl. head and back t-belt cover then your golden

Also I just use big versions of these to hold the T-belt in place

[hendy]

Looks like I'll be getting in touch with Napa again Monday.
However, with the gears lined up right, what would cause it to be stumbling? Also, when it stalls it is backfiring through the intake which has me a bit worried. I manually spun the engine this afternoon and lined all the gears hit where they should, belt is tight but just a slight bit of slack which Id imagine is normal. Should I be looking somewhere other than timing? It goes from a slight miss to smooth at random depending how throttle is held. It can't hold a steady run below 1000 and knock sensor code comes up below 1000 gradually hitting anywhere below 2000 as it warms up. Above that no CEL, period. Any tips for diagnosing the fuel or ignition system? Something has me leaning toward one of the two being the culprit.

[Legacy777]

Have you tried running the active diagnostic with the green connectors only? I'm not sure it'll tell you anything different, but it's worth a shot. Instructions are on my site.

www.surrealmirage.com/subaru/engine.html

[hendy]

Ok, now after some more tinkering today I've became more puzzled. Checked stored codes to start...still knock sensor showing. Started the car and began disconnecting plugs, idle changes, spark verified across the board. Ran active diagnostic per instructions on your site. CEL appears as it should, fans cycle in the oddball manner. On ignition it immediately sends knock sensor code but had a decent running sound (as it did before beginning diagnostics) but immediately flashed knock sensor code constant. Dropping into D throttle has to be applied or it immediately stalls, driving is near impossible to accelerate (fuel cutting out?) After parking it stalled and began code 24 (air control valve) which to me explains fuel cutting out. Could that have been the entire problem all along?

Another odd thing I found was upon trying to check through the black connectors, it flashed a constant light, no slow then fast, just constant equal length flashes. Any ideas there?

Also, rechecked timing and its still in the way I set it which I'm happy about since Napa quoted me $220 for a new hydraulic tensioner.

[Legacy777]

The constant flashing with the black connectors means there is no stored codes.

Here is the test procedure for the knock sensor.

http://www.main.experiencetherave.com/s ... r_diag.pdf

I'd check it, but I don't think it's what is causing your idle issues. The IAC valve may be causing them, but you can try checking it to see if the electrical part is still good.

http://www.main.experiencetherave.com/s ... C_Diag.zip

[hendy]

After reading the fail safe modes for both faults the IAC makes sense to what's happening. My figuring is the knock sensor being a stored code from the fails on getting back in time but the IAC's fail safe makes sense to why it won't run without throttle applied and the extremely sluggish acceleration. Found one for $50 instead of the $400 for brand new so its worth the try.

[Legacy777]

Yeah, if you found one for a reasonable price, it's probably worth a shot.

[hendy]

Got the throttle body and IAC off and apart. Going to test the iac as soon as I can find the multimeter before going all out and replacing it. Main question now is can anyone suggest a place to get the gaskets for each without paying an arm and leg for them?

[Legacy777]

I'd suggest getting Subaru gaskets. Your best bet is one of the online subaru dealers, http://www.subarugenuineparts.com http://www.subaruparts.com or http://www.1stsubaruparts.com

[hendy]

Ended up buying gaskets from the Subaru dealership and got them on today. Tested IAC (9.8 ohms) and cleaned it and throttle body since they both desperately needed it. Ran smooth on start-up, once at operating temp it went back to stumbling. Still throwing knock sensor code but had the MAF code pop up at random but went away. Still acts like it hits a fuel cut when trying to drive also.

Here is a video of idle while warming up https://www.youtube.com/watch?v=rLG_mcL ... ata_player

[Legacy777]

It sounds like it's missing...

I've got a suggestion/theory to try. On a cold engine, unplug the electrical connector for the IAC valve and then try to start the car. The rpms should race and be higher than normal. Let the car idle like you did in the video. If you do not experience the miss or stumble then you may have narrowed down the issue to the IAC valve. If you still have the symptom then the chances are good the IAC valve is fine.

I would suggest you take a look at the MAF sensor, check the resistances of the wiring from the MAF connector to the ECU. Do the same with the knock sensor. The wire may be bad, and that's why the code hasn't gone away.

[hendy]

Well I tested 2 theories. 1 was the possibility of bad gas. Ran tank dry, put 3 gallons of fresh 87 octane, a bottle of STP injector cleaner, and half can of seafoam. Unplugged IAC before even attempting to start. Idle would sit at 750 and die, no erratic idle, just 750 a stumble and dead. Plugged IAC back up and idle sat at 1100ish running smooth, then stumble but not as hard as in the video after a few moments. Also was sending a very blue smoke out the exhaust. Didn't die but then again its 18 degrees out so I went ahead and shut her down until tomorrow daytime.

[Legacy777]

The blue smoke is likely from the additives and sea foam. If the stumble is still there it may be the IAC valve or could be something else still.

I guess if you get more time to test things when it warms up, let us know.

[hendy]

That's definitely where the smoke came from. Searched around and found a thread talking about pouring seafoam additive in the iac main line to clean it...did that and and got a ridiculous amount of smoke although no luck running. Will upload the new video as soon as I can. Checked voltage to harness pin 2-body read 11.6v with ignition on. Reconfirmed ohms across the valve itself and had same 9.8 result. Running active diagnostic car runs like crap but cel has constant flash (recheck on black pins say 22&24 again). Tracking down ecu pinout to check its end of the situation and back to hunting parts for the fallback.

[Legacy777]

Try clearing the codes using both the green & black connectors. If the green connectors don't show any codes, then there shouldn't be anything "actively" wrong. The black connectors just show stored codes.

[hendy]

Well after pulling almost the whole top end of the motor out, cleaning, putting back together, and resetting the timing she lives again. No idea which one part caused my hassle but she's back to smooth as silk (but several lovely oil leaks around valve cover and oil pan). Still throwing knock sensor code but that's going to wait a few more days. Thanks for all the assistance and insight!

[Legacy777]

Glad to hear you got it running again.

[hendy]

Only parts I done differently were setting up the timing slightly different and adjust the IAC (may not have had it back together exactly right when I took apart to clean it). The knock sensor code that threw Friday night was gone Saturday morning and has so far stayed gone (1hr drive 2x per day). So far so good, fingers crossed.