Legacy - Choke issue?

[1994legacyrs]

Hey guys, heres the story (sorry if its long)

(note this is only a problem when cold)

When driving the car cold after around 40 seconds - 1 minute of driving the check engine light would come on for around 30 seconds and then disappear. No noticeable changes, other than maybe a slight loss of power up a steep hill - but barely noticeable.

Well I tried an experiment and left the car running for about 1 minute and sure enough the light came on, it idle extremely rough and died. I started the car and it started with great reluctance (turned the key for about 4 seconds pumping gas) and the light came on and it idled rough, maybe 300-400rpm (but didn't die).

I let it run for about 1 minute and I heard a "click" and the light switched off and the idle immediately jumped up to around 1k rpm (normal idle when cold).

It never was a problem because by the time it happened (1 minute of driving) I was already on the road and I would never be at a stop so I would just keep driving and after 30s the light would go off and it would be fine.

But lately it happened once in town and it was highly embarrassing as it stalled at an intersection ;D

And today for the first time it happened RIGHT when I started the car so it immediately died.

Any thoughts people? Is there an idle mechanism I can take apart and clean or something or is it all electrical. I am hoping this isn't some big engine management problem.

Bear in mind when if you answer that I have minimal mechanical experience and this is the first Subaru I have owned, so assume I don't know anything

P.S While I am on the subject of fixing things, when braking I sometimes experience a shudder. Is this just the ABS? It happens around 80-90 km/h - its defiantly not the rotors because it doesn't happen across the board, only sometimes at at higher speeds.

Cheers

Nick

[ReubenH]

What's the CEL say? Should help you determine what's up. Follow the instructions here:

http://homepages.ihug.co.nz/~ccgrant/celcheck.htm

[1994legacyrs]

I will check that out ASAP. Its raining at the moment so its a bit of a pain.

I had a quick look and there were quite a few wires near the foot well, but I will have a better look when the rain dies down.

[Guest]

+1 on the diag check

As for your brakes, it is more common to have high speed shudder than across the speed range when rotors are running out of true

[1994legacyrs]

Just seems strange that it would only be at a localized speed and only *occasionally* (i.e. most of the time it is fine). If the rotors were warped you would think it would happen most of the time and across the board. What type of tool do you use to check that they are true?

[Guest]

[Why would you cold start the car? normally i just wait in the drive way until the revs drop below 1000RPM and then i feel its safe to start driving]

[1994legacyrs]

Why would I cold start the car :

If there's another way to start it in the morning, I am all ears!

But I do generally wait at least 30 seconds before driving - but I would have to leave it running for quite awhile before it properly warmed up.

[Guest]

 1994legacyrs said:

Why would I cold start the car :

If there's another way to start it in the morning, I am all ears!

But I do generally wait at least 30 seconds before driving - but I would have to leave it running for quite awhile before it properly warmed up.

hehehehe, car engine heater wrap, get home plug car in... wont let it get cold :P

-smurff

[madmike]

 1994legacyrs said:

Why would I cold start the car :

If there's another way to start it in the morning, I am all ears!

But I do generally wait at least 30 seconds before driving - but I would have to leave it running for quite awhile before it properly warmed up.

you wait 30 seconds..??

How bout being nice to the car and let it warm up on a cold morning before you drive it.

3-4 min is all thats required dude.

I have done this to all my cars from day one.

Too many people jump in cars these days stone cold and give them hell right out of the driveway.....

Put it this way.......

Most people warm up before they exercise why not let your car warm up too...

[Durty-Sanchez]

I wait 30 seconds but rarely longer for mine to warm up before driving.. by placing the engine under load it heats up faster so less damage is done. Leaving it to idle until warm means the engine is cold for longer so way more damage is possible. By no means jump in it and go, give it some time to distribute the oil so the parts are at least lubricated (30 seconds or so)

[1994legacyrs]

Hmm, I thought premix ratios on a 2-stroke was a touchy subject ;D

Regardless on whether or not I should wait 4 minutes to warm, the problem still exists. It is still raining so I am sorry I can't get you those codes - but hopefully tomorrow it is suppose to improve.

Btw, where abouts is the light that is suppose to flash? Its not the check engine light is it? I am assuming it will be near the wires, to the left of the foot well.

[Glen]

It is the check engine light.

[1994legacyrs]

Got the codes. I didn't start the car if that makes a difference, I only had the key turned to "ON". I used the Black connectors which I read is the historic error - should I try different connectors for current codes?

I am pretty sure that they are (in order):

12

21

65

I have looked these up and 12 is the starter switch (not too sure on this one). Haven't had any problems with the ignition not working.

21 is the water temperature sensor - maybe this is the problem, it isn't choking or is choking too much because it thinks the temperature is warmer/colder than it actually is?

and 65 is the differential pressure sensor. Wouldn't have a clue about this one, haven't noticed any weird noises or anything.

Diagnosis anyone?

Cheers

Nick

[Guest]

Replace coolant sensor

You will have fans on all the time with this logged and hard start/ driveability when cold

As for 12, do you have an alarm fitted? or a starter motor that doesn't work all the time

This code is not to be worried about at all anyway

65 PD sensor, this is a sensor that looks at turbo pressure difference with the TT system

It is located behind the drivers side strut tower on BD/BG models and on the firewall above A/Cond pipe appeture on BE / BH

the hose's are numbered 21 and 22 that go to this sensor, check to make sure they are still connected at each end

Remember to clear codes after replacing temp sensor and recheck

[1994legacyrs]

To clear codes I simply just connect the black and green correct?

Yes I do have an alarm! The starer motor has always worked and never fails to turnover the engine - the only time its hard to start (still turns over) is after it has stalled as a result to the check engine light problem stalling the car.

The turbo pressure is rather worrying. I have never had any problems with over-boost or not boosting (the gauge confirms this) but I will check the hoses. Would this have something to do with my atmospheric BOV venting the pressure out? Maybe it just thinks this drastic change in pressure is a problem?

I will look into how to change the coolant sensor!

You are a life saver Ichi!

[Guest]

Clear codes. KEY OFF

Black plugs together

green plugs together

Key on and start engine

Drive at speeds above 11km/h, if manual chnage gear also so neutral switch is cycled

CEL will flash at a constant rate when codes reset

Pull vehicle over and turn ign off

Disconnect plugs

Faults codes cleared

Note system will not clear if any codes still present

[1994legacyrs]

Thanks - I got to go to work so I will reset and then check the codes when I get home.

The weird thing I find though is why it usually happens after 1 min of running and not usually right from the get go.

[THUNDA]

could be a fualty sensor of some type, how many kms has your car done? are you sure your reading the codes correctly? (this can be greatly overlooked) do you like apple turnovers?

[1994legacyrs]

KMs are high at 180k, yeah I am sure I read them correctly (I sat there for around 5 minutes double checking). I might try replace the sensor, but I am going to do a few more tests to narrow it down a little bit.

And yes, I love apple turnover ;D

[1994legacyrs]

UPDATE

I cleared the codes and it still had the problem at cold start. It really didn't want to start and I had to pump the gas to get it to bite - once it did it jumped up revs and was fine. When I tried to pull out it lost power and tried to stall, I waited another 30 seconds and it was fine.

I think this fits your description Ichi as a coolant sensor fault. I tried a quick google search and couldn't find any websites that stocks them. I will have a better search later - but if anyone knows of a cheap site to get them from - I am all ears.

Thanks for your help guys.

[Guest]

From memory about $45 from dealer (retail)

[Bazza-NZ]

is it the red one that sit on the cross pipe?

If so i think i have one around here off an engine that i took apart to see how Subaru engines worked, pretty sure its in good condition or at lest you could use to test out

[1994legacyrs]

Hey Bazza, I'm not sure on that.

I found this link: http://bbs.scoobynet.com/general-technical-10/769253-coolant-sensor.html

Its for an impreza but I am pretty sure its the same or similar engine. It says its suppose to be brown - maybe someone knows more about it?

[Bazza-NZ]

 1994legacyrs said:

Hey Bazza, I'm not sure on that.

I found this link: http://bbs.scoobynet.com/general-technical-10/769253-coolant-sensor.html

Its for an impreza but I am pretty sure its the same or similar engine. It says its suppose to be brown - maybe someone knows more about it?

i see, mine might be different, the sensor i pulled off sits on the other side of that cross pipe and an 90% sure mine are red in color, so probably not going to work out