EJ25 confusing power issues

madmat · Post by **madmat** » Mon Jan 28, 2008 4:58 pm

EJ25 97 Outback Auto
Having major lack of power issues. i had a code of cam angle sensor so i replaced the CAS with a spare i had and cleared the code. the power returned for about 2 km then it went back to low power. i checked for codes again and had none. i then reset the ECU by disconnecting the battery and when i started it again it was good for a short time then went bad again. this has happened 6-7 times now.

my thoughts are: when i reset the ECU it goes to a learning mode until it sorts out what is going on. This is why i get good performance for a short time.
I think the ECU is getting a false signal from somewhere but i don't know where.

To drive it feels like the timing is incorrect so i like the idea of the CAS being faulty but when i swap them around i get no change. have checked the plugs and wiring as best i can

Any ideas will be appreciated.

Matatak · Post by **Matatak** » Mon Jan 28, 2008 11:50 pm

if the CAS was screwed the engine wuldnt run wuld it ? i wuldnt think so

neways are u just connecting the black ones and turning ignition on?
if so connect em both and drive the car. see wt ones its flashing when u stop.

AndrewT · Post by **AndrewT** » Mon Jan 28, 2008 11:56 pm

Just a thought, is your spare sensor a known working one? Maybe it's faulty too.

madmat · Post by **madmat** » Tue Jan 29, 2008 6:25 am

i tried to start the car with CAS disconnected and it wouldn't start.
i will drive today with the black wires connected.
i guess they could both be faulty but i would like to try a good one before i purchased one to find out it wasn't at fault. I'll see how much FROG can supply one for.

thanks for the ideas

Matatak · Post by **Matatak** » Tue Jan 29, 2008 8:26 am

sorry i meant connect both the black and green ones and drive it

RSR 555 · Post by **RSR 555** » Tue Jan 29, 2008 8:30 am

Just a thought... 97 Outback has the coil on top??? Does it feel like 2 cylinders are are dropping out? I would look at the bottom of the coil (make sure it's not tracking to the manifold) and the other thing to check is make sure the Ignitor on the firewall has enough Zinc paste between the unit and the bracket that bolts to the firewall. This is common and doesn't give any codes on the ECU.

madmat · Post by **madmat** » Tue Jan 29, 2008 9:13 am

Matatak as i understand it the green ones put the system in a mode where it tests runs things and the black pull the codes by flasing the CEL so are you saying i should plug the green plugs together as well as the black ones and then go for a drive?

RSR555 yes i have the coil on top. it dosn't feel as though it's dropping a cylinder but feels as though it is retarded in the timing???? if it had a dissy i would advance the timing. i will change the igniter as i have a spare and see what happens.

i pulled the plug leads when it was running and it was firing a good strong spark to the manifold. i am also running the NGK Iridium plugs. i have tested the leads and they are all in the middle of resistance spec.

thanks for your thoughts so far.

madmat · Post by **madmat** » Tue Jan 29, 2008 9:15 am

Also at times i feel a slight surging/hunting that happens accross the rev range???

this thing has to many damm problems if you ask me. i can only do one thing at a time cause i'm a MAN.

foxx510 · Post by **foxx510** » Tue Jan 29, 2008 12:37 pm

What does the power drop feel like? Does it run rough at all? Does it feel like it is labouring? How long does it take to go bad after you reset the ECU? Is it time/distance/heat related when it goes bad again?

Sorry for all the questions, just trying to get a better idea of what is going on.

madmat · Post by **madmat** » Tue Jan 29, 2008 3:21 pm

foxx510 wrote:What does the power drop feel like?[/color]Does it run rough at all? Does it feel like it is laboring? How long does it take to go bad after you reset the ECU? Is it time/distance/heat related when it goes bad again?

Sorry for all the questions, just trying to get a better idea of what is going on.

I'm happy to answer ? if you have ideas.
to me the power drop is like it is completely dead until 3200rpm it feels smooth but labored.

after setting the ECU it lasts no longer than 3 minutes run time and can be as little as 20 seconds. I don't think it is heat or distance related as it can happen hot or cold and just doing a stall test and it will kick in. i watched it stalling at 2200 and then drop to 1500RPM.

A new development today is that i was out driving and it was performing as per previous discussions and then as though a switch was turned it started to SERVER LY backfire and cause complete lose of power above 3000RPM. i was able to limp home with the only power available being below 3000rpm which is so underpowered i could bearly climb the hills. it was in 1st gear and 20Ks/hr to get up the hills.

I even had an old fart in his Jag pass the Subaru and that is embarrassing. I'm glad i have tinted windows.

today i have checked and cleaned the earths to the engine no difference.
i also changed the igniter, no difference but i do wonder if that is causing my new problem because it is a very hot day here and it may be overheating. i will change it back later.

foxx510 · Post by **foxx510** » Tue Jan 29, 2008 4:14 pm

What is the longest you have ran it while it had the problem? I know mine didn't start to throw codes with a dodgey O2 sensor until I had been driving it for quite a while after resetting the ECU. You might have crook wiring on your CAS, it might not have had time to pick it up and store it yet, even though it is faulty. I'd be pulling the computer out and checking for corrosion on the pins too, it could get wet pretty easily where it is. Do you know the history of the car?

madmat · Post by **madmat** » Tue Jan 29, 2008 4:33 pm

foxx510 wrote:What is the longest you have ran it while it had the problem? I know mine didn't start to throw codes with a dodgey O2 sensor until I had been driving it for quite a while after resetting the ECU. You might have crook wiring on your CAS, it might not have had time to pick it up and store it yet, even though it is faulty. I'd be pulling the computer out and checking for corrosion on the pins too, it could get wet pretty easily where it is. Do you know the history of the car?

i drove for 2 hours today and saw no codes even though it ran like a dog as mentioned. i don't have a code reader just the CEl light system.

i will look at the ECU but i have had the car 3 years. i have just had the motor out to do the heads and so i think it is connected to this work. "Mum always said don't touch" now i know why:-D

Ben · Post by **Ben** » Tue Jan 29, 2008 4:57 pm

Crazy out there suggestion....

Could be an intermittently bung fuel pump... Can't supply pressure and car dies, ecu increases duty to compensate, fuel pump comes good and dumps fuel into engine causing dying and backfiring?

Maybe just maybe...

madmat · Post by **madmat** » Tue Jan 29, 2008 5:02 pm

hadn't thought of that but i have a spare pump so i could change it over.

foxx510 · Post by **foxx510** » Tue Jan 29, 2008 5:13 pm

If it happened after the motor came out, it could be a number of things I suppose. Fuel/pump blockage is possible. Check you haven't got a vacuum leak, or have left a hose off or reconnected some vac hoses incorrectly. Any possibility it's internal? Crook valve or something? I guess you would hear that if it was. Check all the wiring and earths again. Good luck.

madmat · Post by **madmat** » Tue Jan 29, 2008 5:28 pm

i don't think it's internal because it runs sweet when i reset the ecu. also it is variable which is unlikly to be mechanical.

RSR 555 · Post by **RSR 555** » Tue Jan 29, 2008 5:35 pm

If it's back firing, I would think it's staving of fuel. More the opposite, like the duty cycles on the injectors are too long... Have you got another ECU that you can try?

foxx510 · Post by **foxx510** » Tue Jan 29, 2008 6:38 pm

madmat wrote:i don't think it's internal because it runs sweet when i reset the ecu. also it is variable which is unlikly to be mechanical.

I guess I was just thinking it may be valve issues, as I remember you having oil flow problems when you rebuilt it. Unlikely, but worth looking at.

madmat · Post by **madmat** » Tue Jan 29, 2008 9:02 pm

your right about the oil but it seems to idle ok and agin it has performace when i reset the ECU. if it was valves the problem should be there all the time. Anyway i will keep it in mind and get hold of a compression tester.

SUBYDAZZ · Post by **SUBYDAZZ** » Wed Jan 30, 2008 1:11 pm

Just a question, but does disconnecting the battery really reset the ECU? On the Liberty there is a slightly complicated dance of plugs and accelerator pedals, gear-changes and ignition key turning to reset it and clear codes.