EJ25 confusing power issues

Matatak · Post by **Matatak** » Mon Feb 11, 2008 10:08 pm

Morcs wrote:Vavle Clearences maybe too tight causing vavle to ride open when every thing heats up (expands).
Can you get access to a data logger?
I would have ago at logging afm and O2 senser.
Afm Sensers can be finiky things at the best of time,
log to see if they go out off range.
All else fails could be making a trip down sydney l8tr this could try swaping it for my link ecu.
As link Ecu does not use AFM input.

Valve clearances is a very good suggestion.
i dont know how theyre adjusted on the EJ25. wether only hydrualic or manual.
but it culd be a possibility.

when it starts losing power do u disconnect the battery when it cools and try something else.
have u let it run to cold again after that and seen wt the power is like at cold after ECU has 'learnt'.

madmat · Post by **madmat** » Tue Feb 12, 2008 5:43 am

the tappets are correct i have checked them.

i have cleared the ecu both hot and cold and while it is learning it will go fine and then once it gets to close to full temp it will start to play up and then when it gets to temp it will drop all power except for above 3000prm. if it is really cold it will be fine for 3 -4 minutes if it's been run it will take much less time. once it looses power it won't come back until i reset the ecu.

thanks for thinking on it for me.

foxx510 · Post by **foxx510** » Tue Feb 12, 2008 7:00 am

You are still not getting any ecu error codes then? And you say you have changed every sensor and even the ecu?

madmat · Post by **madmat** » Tue Feb 12, 2008 7:48 am

Thats correct foxx510. i'm about to give up and take it to the pros. trouble is i don't have the open check book.

foxx510 · Post by **foxx510** » Tue Feb 12, 2008 7:55 am

Sounds like a total pain in the arse. You must be completely over it by now!

madmat · Post by **madmat** » Tue Feb 12, 2008 11:45 am

pain is not the right word!!!! i am going to get a pro to look at it this afternoon. will see what he says. i think whenever i find the problem it will be some stupid little thing that i should have picked up straight away.

FROG · Post by **FROG** » Tue Feb 12, 2008 12:57 pm

good luck mat !!!!!!!!!!!!!!!!!!!!!!!!!

Morcs · Post by **Morcs** » Tue Feb 12, 2008 8:11 pm

Just Wondering as someone said earlier in the thread you had oiling issues iam wondering if the oil you are using is too thin or there is a gallery blocked and the hydrualic lifters are compressing because lack of oil pressure at low revs.
For most australian conditions you should be using a around about a 20/50 weight oil. Check Manual for correct temprature ranges

Oil gets thinner as the temprature rises.

FROG · Post by **FROG** » Wed Feb 13, 2008 6:52 am

he has shims no hydraulic lifters

Morcs · Post by **Morcs** » Thu Feb 14, 2008 10:32 pm

A map senser on the way out could give some interesting symptoms not sure wether it would bring up a code though. On cold starts there is a fuel enrichment untill it heats up to running temprature it would decay away until it hits a stable operating temp Controled by ecs Engine Coolant senser.

Just wondering wether map senser is under reading in certain vacum settings.

madmat · Post by **madmat** » Thu Feb 28, 2008 5:07 pm

a quick update here. I've been busy with work and so no time to play with it but the latest is.
the Subaru mechanic has come to the conclusion that the heads i put on must be incorrect for the motor. the only problem he and i see with this is that the motor runs great when i reset the ECU and the motor is cold.
anyway it looks like i may be doing up the old heads and starting the job again

:mad:
of course this will cost some $$$ and then may not solve the problem.
the job has now run out to about 8 weeks and $2000 with no solution.
if anyone had a spare engine that runs that i could try before i go down the road of doing up heads that would be helpful. (you can have it back after the trial) you see i have time to swap engines in and out but not the $ to waste if the heads are not the problem.

any more ideas are welcome

LongtimeAddict · Post by **LongtimeAddict** » Thu Feb 28, 2008 6:18 pm

I'm running an almost identical thread so I'll add my thoughts here and see what happens. History :- 89 L series MPFI. Car was running beautifully (this is my 10th subie and by far the best performance wise), went camping one weekend in Jan and did a few gravel roads with a couple of creek crossings and on the way home it didn't seem to have as much power. Since then it has been getting progressively worse. The symptoms are very similar to madmats.
1 First thing in the morning it will start fine and idle about 1400/1500 while it warms up. Within 1 to 3 mins revs drop to about 400 and engine starts running rough.
2 If you drive on flat roads with minimal acceleration it performs reasonably, however if there are hills or you try and put your foot down, there is an extremely slow increase in revs accompanied by surging & hunting as madmat said. This continues until you get above 3000 revs and then it seems to have more power but nothing like it should. If it had an old distributor I would say the auto advance was stuffed.
3 I have replaced plugs, leads, fuel filter, air filter, dizzy cap, rotor, slotted disc in dizzy, coil, igniter, ecu, exhaust from manifold to past cat converter (including o2 sensor). Cleaned air flow meter, added injector cleaner, removed injector plugs one by one disconnected most sensors in turn. I put it into Scorpian (subie specialist) and they couldn't find the problem.
4 I was getting round 450ks to a tank and it is now down to 320ks.

OK some theories/questions:-
Madmat have you changed the fuel pump yet? I haven't but i will this weekend. The issue seems to me to be fuel.
When I disconnect the AFM I get the check engine light and error code. When I disconnect the o2 sensor it makes no difference to performance and no codes - is that the way it should be?
Can you go to jail for taking a sledge hammer to a subie?????????????????

LongtimeAddict · Post by **LongtimeAddict** » Thu Feb 28, 2008 6:29 pm

PS I don't think its your heads, hadn't touched my engine when this problem started.
Tony

madmat · Post by **madmat** » Thu Feb 28, 2008 6:31 pm

i will try the fuel pump even though i can't see it as my problem. it certainly sounds like similar problems that we have.
i have an old subi that you can hit if you need to.

Matatak · Post by **Matatak** » Thu Feb 28, 2008 6:37 pm

how can it be the heads though ??

that wuld be weird

madmat · Post by **madmat** » Mon Mar 03, 2008 9:21 am

i can't see it being the engine either because it wouldn't run well after the ECU reset????

madmat · Post by **madmat** » Mon Mar 10, 2008 8:39 am

Another update. (i hope this all helps someone oneday)
my old man came over to have a look at it for me last week and i said let me show you the problem and it wouldn't do it, it ran fine for 15 minutes then it started to loose power.

So after playing around for a while to no avail i decided to just start driving it around to see what would happen and: the problem now comes and goes. somtimes i start the car and it drives great for 15-20 minutes then it will loose power and not come good until another restart. it is not garrantied to come good on the restart though. it could be bad or good???
i'm going to see if i can get the output readings of the sensors in both the good and bad senarios to see if that shows me a fault.

this is not fun anymore i'm really sick of it.

madmat · Post by **madmat** » Thu Mar 13, 2008 9:13 am

well ladies and gentlemen that have been following this thread waiting in great anticipation of what the heck is wrong with my car:rolleyes:
Well i don't know and have given up. if you want to buy it and have a go feel free to contact me. some might feel i'm giving up to early but 2 months and many $ i don't have lead me to put it in the 2 hard basket. Even the other mechanics have given up on it so away she goes to where all good subis go.

the funeral will be short as i jump ship and get myself an 80series Landcruiser. (is that like swearing here?):p

madmat · Post by **madmat** » Fri Mar 14, 2008 2:38 pm

Ok after a little bit of sweet loving from the outback (don't deny it you do it to) i've decided to get a diagnostic specialist in to have a look at it. it will be interesting to see what comes up. $220callout $88/hour. so i'm not eating for the next week. he is coming on tuesday so i'll give an update then.

FROG · Post by **FROG** » Sat Mar 15, 2008 10:10 am

dont need to eat just get that car fixed and no more talk of toy**@s