alright folk ! bought this new to me 1989 gl wagon ea82 spfi 5 speed 4wd subaru about 3 weeks ago.

First it start alright when cold but once warm up it will start idling crazy high around 2500 - 3000 rpm
after trying to clean to iacv nothing changed, so i decided to leave to the iacv motor disconnected for the moment being so i could still use the car without destroying the clutch

So i now have to give it gas to warm it up, but after warming up for 2-3 minutes at 1500rpm, it start to stumble usually it will drop 2-300 rpm and pick up again without moving the gas pedal.

It get worse if the car is under load (accelerating or cruising), to some extend it will bring to vehicular to a stop and stall and then i have to wait 20-30 minutes before i can start it again while i literally need to floor the gas pedal for it to start and then will stumble really bad until it pick up a few rpm.

it only happen when the engine is not quit warm up all the way, once the temp seems to stabilize (running temperature) it run perfectly fine and will idle around 1200 rpm (still to high per fsm wich should be around 550rpm with the iacv disconnected.

when it start to stumble under load if i floor it it stumble much harder, i have to let my foot of the gas then ease back into it it will stumble again, but by depressing, coasting for a little bit and pressing the gas pedal again it seem to help clear the engine up.  but evrything wont smooth up until engine is fully warm up.

hopefully my description is not to over whelming and precise enough for people to understand lol, also ive heard alot that cts might be toast, i havent had a chance to run the volt meter to it yet but it wouldnt be suprise if its bad... i've been trying to find a new one online but they are all asking over. 100$, anychance someone could point me where to find one beside my local junkyard ? thx you everyone

are there any computer codes being displayed ?

Trying to run with the IAC valve disconnected, who knows.  I never did that.  I had one die, electrically open, and the car would shut off if I let it idle.

 

THE CTS can cause all kinds of crazy drive ability problems, idle all over the place, shut down / stall, etc.  It can be bad in  a way that causes this, and NOT throw a code.  Reason is that it is telling the ECU how cold / hot the engine is, and this information is used to adjust how much fuel is sent in.  If the mixture is way off from what it needs to be as determined by the temp, the engine won't run well, if at all.

If you have an ohmmeter, you can check it.   Run the car until it's at normal temperature.  Shut down.  Disconnect the CTS - the 2 wire sensor on the thermostat housing.  Measure the resistance.  Note it.  Really helpful if you have a thermometer also, so you know the temperature of the housing.  Wait a while, until it cools a noticeable amount, repeat the readings.  Do this a few times while it cools to ambient.  #1 thing to watch for is the reading is STEADY vs jumping around.  Also, it should drift in the same direction each reading.

There are temperature & resistance range notes in the FSM.

I bought an OEM CTS a few years ago, from a dealer.  It was around $90.00.  But the previous one lasted nearly 30 years.  Not to bad, $3.00 per year.

 

Well maybe ill just bite the bullet and hope it solve my issue.

I’ve also heard of ppl using the MPFI temp sensor too. 

From memory they adapt the SPFI wiring to the MPFI sensor.

I hope it’s as easy as replacing this sensor!

Cheers 

Bennie

any advice on changing over to the new temp sensor ? is coolant gonna gush out when i remove the old one ? do i need teflon tape on the threads etc. ?

thx in advance

 

4 minutes ago, darkflame221 said:

any advice on changing over to the new temp sensor ? is coolant gonna gush out when i remove the old one ? do i need teflon tape on the threads etc. ?

thx in advance

 

Yes, coolant will drain from there. Drain some coolant from radiator, catching it in a pan. Use Permatex No.2 non-hardening sealant on the threads.

There should be a sealing washer on the old one so just clean that & manifold surface well, flip washer over, add sealant & install. 

If you still have running problems, get a can of contact cleaner, disconnect all sensors & clean the connectors well. I've had trouble with road salt & water causing poor connection on my 87 GL since driving thru PNW. You  could be chasing your tail throwing parts at it if there are poor connections. Ask me how I know....

all right guys, just installed my brand spankin new oem 150 $ cts, with no luck, even tho i highly believe the old was toast (no continuity). 

Nothing as changed, still idle way too high around 2500 3000 rpm.

where would you look next ? im just about to build myself a smoke machine to search for vacuum leaks, and then maybe verify voltage at the MAF, and then check the tps continuity when throtle is closed + verifying idle stop screw gap to make sure no one as tempered with it

any tips suggestion advice or where to start first would be highly appreciated bcz that 150 $ sensor got me really excited, but now really sad thx

edit i also did clean the iacv about 2 weeks , but not 100% ive done it properly,i did take the motor out and try to clean by using intake cleaner and qtips and sprayed a good amout through the air port coming from the top but that about it, should i have taken completly apart ? if so what that easiest way to get it off since everything seems to be in the way of the screws :/ 

 

Edited March 16, 20197 yr by darkflame221

51 minutes ago, darkflame221 said:

all right guys, just installed my brand spankin new oem 150 $ cts, with no luck, even tho i highly believe the old was toast (no continuity). 

Nothing as changed, still idle way too high around 2500 3000 rpm.

where would you look next ? im just about to build myself a smoke machine to search for vacuum leaks, and then maybe verify voltage at the MAF, and then check the tps continuity when throtle is closed + verifying idle stop screw gap to make sure no one as tempered with it

any tips suggestion advice or where to start first would be highly appreciated bcz that 150 $ sensor got me really excited, but now really sad thx

Disconnect your MAF, clean contacts like I meantioned above then gently bend open side of each contact a little with toothpick or other small pointed tool. Idea is to make sure all contacts are clean & tight. Do the same with TPS connector.

Do not clean MAF with MAF cleaner, it may cause more problems. Just inspect it for broken sensors or corrosion.

Clean IAC valve connector well. Pull hose off IAC valve & spray some Seafoam in open tube of valve. Start engine & give it a few revs.

Check & clean your engine main connector(s) at DS near DS valve cover. Same thing as others - no green corrosion, scale or dirt.

Your ECM is working with a meager 5V at best from these sensors,  some much less. Any corrosion will add resistance causing false sensor readings. 

Edited March 16, 20197 yr by czny

When it is cold, like winter cold, those rpms are not unusual for at least the beginning.   Yes, if the old one was open, you needed a new sensor anyway, so at least that wasn't a waste of  $. 

Ditto, check the wiring / contacts / continuity.  I would check the resistance of the cts from the ecu connector.   

On 3/16/2019 at 2:24 PM, darkflame221 said:

all right guys, just installed my brand spankin new oem 150 $ cts, with no luck, even tho i highly believe the old was toast (no continuity). 

Nothing as changed, still idle way too high around 2500 3000 rpm.

where would you look next ? 

 

Check codes next or sooner.

Are you sure the CTS was open?That would have set a code.

Bad MAF or electrical connections won`t give 1500 rpm w/the IAC unplugged.

Too much air is almost the only reason

Vacuum/unmetered air leaks most likely,IAC sticks open,throttle doesn`t close,misadjusted idle speed screw .......etc

Almost certainly a vacuum or unmetered air leak.Fits your sputteriing symptoms

Check the large hose and all connections between the MAF and throttle body for cracks and tightness

Compression test wold not hurt.

Run a fuel system cleaner product through all the fuel lines, starting with the gas tank.

all right new chapter to my story

briefing : still running with the iac valve motor unhooked, changed the cts for a brand new oem one.

did a vaccum test yesterday with a diy smoke machine, to found a leak on what look like to be the egr vaccum modulator (look like a thermostat) and some other vaccum line wich i have fix, (replaced the egr vaccum modulator with an extra one that was on the extra intake manifold that came with the car) edit egr valve ?

nothing changed, but ! now that the snow finally finished melting and that my drive way is dry ive come to realize that i have a fuel leak near the fuel tank. It only leak once the car is started and i can hear a good hissing sound (vaccum leak i presume) coming from the leaky area near the tank

so now how do i proceed, how do i test the egr system ? etc etc thx ! only thing i havent done that i think could be the culprit is tchek tps and maf with volt meter and tchek tps idle screw  proper gap since im not to sure where is the gap to check, and also some more info on the fuel system ( pressure reading  check valve return line filter location etc ) would be really appreciated thx.

im re reading myself and it sound really hard to follow up with me but hey ! i still have hope XD

 

Edited March 24, 20197 yr by darkflame221

EGR.  There is a solenoid mounted on the intake.   It is controlled by the ECU.  It disables the EGR until the engine is up to normal operating temperature, as determined by the ECU reading the CTS.  The solenoid causes the EGR valve to stay closed when disabled, or open depending on the vacuum system.  The EGR valve hangs off the back of the intake on the passenger side.
Vacuum applied to it's hose barb pulls it open.  IF the solenoid coil is open, the ECU will detect it, and blink a code on the LED on the ECU.  I have never had an open solenoid coil cause any drive ability problem.  OEM solenoids are notorious for failing open.  I replace them with Toyota solenoids.

If you follow the hose from the EGR valve to the solenoid, the other hose on the solenoid could be pulled off and blocked to stop air from sucking into the manifold.  The car  might be a little more inclined to experience knock, make more emissions, but otherwise run ok.  That test would isolate if you had a leak in those few pieces.
 

Proceed by forgetting about everything else until  the fuel leak is fixed.

There are no vacuum lines back there to hiss.

The hiss will be a high pressure fuel spray. YIKES!!

You need to get under there and have a look ASAP.

If your idle is still too high,there is another vacuum leak.

Try adjusting idle speed via the large brass idle speed screw on the throttle body.

Service info you seek is in the 2nd ea82 manual here http://jdfinley.com/file-downloads/subaru-manuals/

Edited March 25, 20197 yr by naru2

@naru2 what about the evap system doesnt it go all the way back there too ?

Only a vent line to the cannister.

No vacuum.

@naru2Thanks for the service manuals! Got the Hayne's, but it's awesome to have the Subaru manuals. 

I like to try inexpensive, practical things first. Buy a good quality fuel system cleaner, one that is designed for FI. Run it through the system, even more than once. That should give you a baseline for more diagnosing.

2019 best-rated fuel injector cleaners:

http://oilandwaterproject.org/best-fuel-injector-cleaners/

 

I had a similar problem with my 84 wagon. It sat in the driveway all winter when I needed it most.  I swapped carbs, reran vacuum lines, replaced egr system, all the filters were replaced, went thru everything the home team thought could be wrong with it.  Spring comes, someone suggested looking into the catalytic converter to see if it was plugged.  Sure enough under pressure that carbon blockage made it sputter and die out.  Not all the time  Just whenever it blocked the exhaust hole up.  (facepalm)

 

She was trying to relieve her waste fumes and kept belching them back up.

Edited April 10, 20196 yr by SpecialEd