91 Legacy Idle problem

[johnsnavygun]

I have an almost 350 rmp rythmic bounce to my idle. To keep my legacy wagon 4wd running, I had to turn up the idle. Upon further inspection I heard a "gurgle" coming from the air box. There is a un-identified sensor just past the filter before the air tube, that I can only assume the issue is. Can anyone identify this sensor, and is there a way to test/ fix without purchasing new.

 

Or is it one of the $5 parts that goes in with 5 min of elbow grease?

 

Thanks

[beezer]

Think you are talking about the MAF (Mass Air Flow) sensor. I don't know if there are tests for it or not. How much it costs I don't know. I think you can clean it with some electrical connector cleaner.

 

The idle screw on the throttle body really shouldn't be tampered with. It is set from the factory. I heard people have had slight idle issues after playing with the screw. The only way they fixed it was to get a new one.

 

Good luck!

[johnsnavygun]

OK yes after some time on partsamerica.com it is the MAF and the price is about $200-350 so yeah need help if anyone has had success cleaning MAF's

Thanks for your help.

 

Will post outcome

[beezer]

Is the "check engine light " on?

 

Check out Legacy777 website if it is.

 

Can you explain the "gurgle" more.

 

What does your air filter look like?

[Olnick]

I'm no MAF guru by any means but I've been in there a few times. Here are my thoughts:

 

1) Replace the air filter if you haven't already.

 

2) Remove the MAF and intake tubes--disconnect from the air filter box outlet and at the throttle body intake, disconnect the smaller air line that goes to the IACV and unplug the wiring connector--should lift right out.

 

3) Clean the vertical wires inside the MAF very gently. I just sprayed mine with carb cleaner and let drip-dry. Some people have mentioned wiping down with Qtips but I've never physically touched mine.

 

4) Clean the wiring plug too.

 

5) Inspect all the air tubes for holes.

 

6) Might want to clean the throttle body and idle air control valve (IACV) and replace the PCV too. There are good write-ups for these here on the board.

 

7) Button her up nice and tight.

 

8) If you find you do need to replace the MAF you might try to find one in a pull-and-pay--be a lot cheaper than a new one.

 

9) Keep asking questions here.

 

Sheesh! Sounds like "9 Steps To Happiness!"

 

Anyway, good luck.

[johnsnavygun]

No luck on the MAF, I took Olnicks advice...kind of and went to the pull apart $10 for the maf, well needless to say indications didn't change. Yes the check engine light comes on randomly seems to be with the rythimic gurgle. ok so just working my way down the line could it be the PVC valve or the IACV if so where do I find these specificly. The opposed 4 is totally new for me.

 

Thanks

[johnsnavygun]

So I'm a little embarrased I did pull the magnetic head from the IACV and clean it as well as the PCV valve to do so I had to unhook the electrical connection for the coil and IACV (if you are going to do this ensure you scibe the top of it to sync your location back up, but long story short all this and an oil change (just bought the car so I didn't know condition) and she's back to running like a raped ape!

 

Word to the wise and I just took it for granted (wisdom from my DAD) always do an oil change, air filter, timing belt, cap, rotor and spark plugs just after buying a new to you used car.

 

Thanks all!

 

I expected worse as this subie has 217k miles on it and now runs like new once again!

[korrupt66]

found a MAF sensor on ebay http://cgi.ebay.com/ebaymotors/1990-SUBARU-LEGACY-MASS-AIR-FLOW-SENSOR_W0QQitemZ8018403257QQcategoryZ33557QQrdZ1QQcmdZViewItem

[Olnick]

 

That's great news. Congratulations!