Page 1 of 3

Timing?

Posted: Mon Aug 18, 2003 1:57 am
by jim
I have a 91 legacy purchased in feb. purred like a kitten for about two days then check engine light came on and rough idle i put new plugs, wires ,and replaced timing belt still did not idle good but ran well at driving speed. still trying to figure it out i replaced maf sensor, fuel injectors and filter no difference. Recently the crank pulley bolt came loose tightend it twice the third time it sheared the woodruff key,after searching high and low i finally found a used pulley ($50) and the key at a dealer. i put the same timing belt back on since it s only 6 months old and reused the tensioner, new plugs(old plugs carboned up and the #1 slightly pitted) iam sure the marks are all right on but idles really rough and bogs when you give it gas check engine light still on.
Sorry for the long history.
Any suggestions
jim

Posted: Mon Aug 18, 2003 2:20 am
by vrg3
Read the Check Engine Light code!

http://www.surrealmirage.com/subaru/engine.html

There's no point in randomly replacing things; the engine computer will tell you why it turned on the light.

Posted: Mon Aug 18, 2003 3:35 am
by jim
I checked the codes and the knock sensor, canister purge solenoid valve, and idle switch came up. Now i need to find them. I know i sound dumb replacing random parts but iam not alone , since two garages i talked with said the codes would not tell me anything specific, so i saved the hundred bucks.
Thank you so much for the advice :D
jim

Posted: Mon Aug 18, 2003 3:55 am
by vrg3
Oh, you definitely can't take the codes as gospel; they just give you a place to start. It's certainly possible for a part to fail and not throw a code or to throw a different code.

It could just be the idle switch. The idle switch is part of the throttle position sensor.

If the knock sensor is the original one, you might want to replace it since the sensor has been redesigned since. I don't see how it could affect your idle but for about $35 it can't hurt to upgrade to the current sensor design.

The purge control solenoid could be affecting your idle too, if it's upsetting the air/fuel ratio too much. It's a bit of a pain to replace, from what I understand.

All three of these sensors have been discussed in earlier threads so you should be able to find a lot by searching. The idle switch may just be miscalibrated but the others you'll probably want to replace.

Posted: Mon Aug 18, 2003 6:02 am
by entirelyturbo
vrg3, I actually found my idle to be slightly smoother after a new knock sensor. I know, makes no sense, don't see what situation would cause knock at idle...

I vote the canister purge valve. That sucker is bound to go bad on our cars. Most of us here have had some problem with it. I had the dealer replace mine a few years ago, so I can't attest to its difficulty, but it's under the passenger intake runners, so yeah, it would be interesting...

Posted: Mon Aug 18, 2003 2:57 pm
by Legacy777
reset the ECU, if codes clear run the car until you get CEL again and then go from there.

Posted: Mon Aug 18, 2003 4:31 pm
by jim
I reset the ecu, now i have no codes and the check engine light doesn't come on. the car acts like the timing is off. How do i know if the cams are on the right stroke, does the revolution matter when all the marks line up and the crank is on the compression stroke?
Please help I need this car running today :cry:

Posted: Mon Aug 18, 2003 5:07 pm
by vrg3
I haven't done a T-belt job myself, but I think if you have piston #1 at TDC and the marks all line up, then you're good. I don't know exactly what you mean about whether or not the revolution matters.

Were you really careful with the tensioner when you reused it? You have to compress it gently and carefully, which is really hard considering the force required. You should probably get a new tensioner this time around in any case.

I think subyluvr2212 can give better advice on the timing belt since he did the job fairly recently.

Does the engine run rough only at idle or at all engine speeds? If it seems to happen just at idle you may have a vacuum leak. You can get a can of starting fluid:
http://www.peakantifreeze.com/peakstartingfluid.html
and spray around the intake to try to find one. If it sprays near a leak at idle it will affect the idle speed.

Posted: Mon Aug 18, 2003 7:45 pm
by jim
I reset the ecu again and now i get the Knock Sensor and the EVAP Purge Valve. The only place i can get them in this area (SE MN) is the only Subaru dealer
the knock sensor $244 and EVAP $82
any opinions on replacing one or both?
where is the EVAP valve on a 91 Legacy? :x
jim

Posted: Mon Aug 18, 2003 7:58 pm
by ciper
The purge valve wont effect how the engine runs.

The knock sensor will only retard spark timing, producing less power. It also wont make the car run badly.


A new knock sensor should cost around 40$, was that a typo?

The evap valve is right above the passenger side rear cylinder, underneath the intake runners.


Both of these are common failures. I suggest replacing the knock sensor and leaving the EVAP valve the way it is.

Posted: Mon Aug 18, 2003 8:44 pm
by jim
No typo on the knock sensor $244 price quote from dealer.
If the timing belt tensioner was not working properly but the timing marks line up would that effect timing?
Not used to Subarus, old GM's more my style, seems like a motor out of time to me.
I think I going to put a new tensioner and belt on and start over.
Thanks to everyone for the help.
jim

Posted: Mon Aug 18, 2003 9:47 pm
by petridish38
i've done a timing belt job on my legacy about 4 times so far...one to replace the actual belt...one to replace the water pump, and 2 times when i did the head gaskets(messed up on the first one).
Just make sure that cyl. #1 is at TDC and line up the cam marks with the belt marks. the best way i found to compress the tensioner is to put it in a vice and SLOWLY close it(just keep turning with an even amount of pressure and kinda let the tensioner sink in by itself) it should take a minute or two. then I stuck a clothes hanger through the holes(a small allen wrench would work too) and pulled it out after the tensioner was in place.

good luck!

Posted: Mon Aug 18, 2003 10:19 pm
by ciper
Your dealer must be smoking dope. Give them this part number 22060AA031

Ill sell you a used working unit for 20$! I replaced the knock sensor with the updated unit on all my legacy even if the old one wasnt bad.

Posted: Mon Aug 18, 2003 11:20 pm
by jim
I went to the dealer to pick up a timing belt and tensioner and had them check the knock sensor again $60.
So iam back at.

Posted: Tue Aug 19, 2003 12:38 am
by petridish38
also, i did the "U-check" or whatever and it gave me like 8 different codes...all 4 fuel injectors, and a couple other things....but when i did the "D-check" and drove it around all it gave me was the "Purge control solenoid valve"... so i replaced that and the check engine light went off and hasn't been on since.....so I would try the "D-check" and drive it around for a bit. I tried re-setting the ECU but i guess i couldnt figure it out.....eh, i dont know.....

good luck again!

Posted: Tue Aug 19, 2003 12:59 am
by jim
I changed timing belt, tensioner , and knock sensor . Still idles rough and almost dies when i give it gas :evil: i checked plug and there carboned up is it a fuel problem? Iam lost!
jim

Posted: Tue Aug 19, 2003 1:20 am
by entirelyturbo
I understand what you're saying about the "revolution" thing. Getting confused about where each cylinder is in relation to the valves since the crank turns at twice the speed of the cams.

If all your marks line up, then you should be on TDC for #1 on the compression stroke. If you had a cylinder or stroke messed up, your car wouldn't run, period. You got that right.

Whether you got the marks exactly right, I can't say. One notch on the belt off could significantly affect the engine's running quality. Don't be hasty when setting the timing! I took my belt off completely 5 times until I was sure all the marks lined up exactly after tension was applied to the belt. My car has run just peachy ever since...

Hmmm, plugs gunked up, running very rough, how's your gas mileage been lately??? Dare I say MAF sensor? No you didn't get a code for it, but a MAF can get finicky without throwing a code, and piss off the other sensors in the process...

Posted: Tue Aug 19, 2003 3:11 am
by jim
The marks on the belt are right on the notches on the cams and crank, all at the 12'o clock position #1 piston on compression stroke. Am I missing something?

My gas Mileage was about 27 miles / gal. seems low?

MAF sensor was one of the first things I replaced. It was from a salvage yard , they said it tested good. Ive tried to test it using my chilton but I dont get it. The book says to check the terminals of the unit resistance to ground, not the connector, and it says four terminals I count five.

I did the D-check mode and got the knock sensor ,i assume because I didnt reset after i replaced it, and the EVAP purge valve. Could that make the car run that poorly, undriveable.

Any more ideas anyone?
Thanks
jim

Posted: Tue Aug 19, 2003 3:22 am
by vrg3
27 miles per gallon seems okay...

As for the MAF sensor, you can test it electrically but if your car runs at all, the MAF electrical test won't reveal anything. It couldn't hurt to try cleaning the MAF sensor out a little with brake cleaner or carb cleaner though.

Posted: Tue Aug 19, 2003 4:07 am
by ciper
27 miles per gallon is insane, you must have hard rubber tires ine 185mm width pumped to 60 psi!

Posted: Tue Aug 19, 2003 6:53 am
by entirelyturbo
No kidding!!! I have never averaged 27 mpg on a tank since I've owned the car!

Could that possibly mean that your engine is being starved of fuel? Or is that a little too lofty of an idea?

Of course then, you should get codes for abnormal injector output...

Those two parts will not make the car run as bad as you're describing. Only one who is unhealthily obsessed with their car would notice the difference...

I did... :lol:

Posted: Tue Aug 19, 2003 8:22 pm
by Legacy777
buy your parts online from liberty subaru www.newsubaru.com

the canister purge solenoid can cause a slight irratic idle if the valve is open, but shouldn't be too bad.

Posted: Tue Aug 19, 2003 10:16 pm
by ciper
Legacy777: I think the valve fails closed.

Posted: Tue Aug 19, 2003 10:29 pm
by Legacy777
ok......yeah I'm not too sure what position it fails at, but I have heard of some people having idle issues and when replacing the valve idle issues are gone. May be on a specific case-by-case situation.

Posted: Wed Aug 20, 2003 12:19 am
by jim
I figured it out, finally, Thank God!
One tooth on the reluctor ring of the crank sprocket was broke off, screwing timing up.
I should have replaced it from the begining but thought it was O.K. I know iam a moron.
Runs great now with all the new parts :D
Thanks for all the help its a great site hopefully i can check out for the fun of it and not because of a break down.
Jim :lol: