eg9_fann

hi

iv just moved on here from the itr-dc2 forum.it seems people on here seem abit more knowledgeable judging by reading some of the posts (lol)

iv recenty put a new engine in my dc2.now i have a misfire on cylinder 1 intermittently.

i have a small collant leak to but thats a pipe near the intake manifold and its NOT the headgasket

the car runs fine once driving....and is normaly ok at idle but sometime if i let it idle too long cylinder 1 starts misfiring.

so far iv :
-changed the plugs
-changed the leads
-thought it was the dizzy/swapped it with a ek9 dizzy...didnt work then swapped it back over
-my old dizzy failed after a few days iv replaced it with a junkyard 1 (car would start when i changed it it started)-i changed the injector on cylinder 1.....still no change.

when the car idles normally...theres no mising and i remove the electrical connection from the injector plugs i get the symtopm of mising which is normal.

when the car is on the misfire...taking off injector 1z wiring makes no difference

so for some reason on idle after a few minutes injector 1 stops firing fuel..soon a si set off and drive the car runs ok...until i idle again for a few minutes.

i also put in some valve cleaner into the engine oil...ran it for 20minutes then changed the oil.seemed ok for a while then back to normal again.

now am thinking could i have bad valve lash clearance on valves in cylinder 1? sticking valles/burnt vallves which dont move so freely at idle when oil pressure is low in the head or maybe leaking exhaust gas into the combustion chamber?
also get white smoke/subaru burble when the misfire happens.but if no fuel is being injected the white smoke cant be unburnt fuel?

1 thing i will say is that when i changed the dizzy over i didnt adjust the timing and i cant really say the garage who put the engine in did it either.

can bad timing cause a misfire on 1 cylinder only intermittently on idle?

any input would be appreciated.

my next step is getting the valves checked.

iv ran a diagnostic machine on it and got a 9-1 cmp (camshaft sensor A no signal code and a cylinder position sensor circuit malfuntion.

i cleared these but they haven't came back so im thinking they were down to the bad dizzy because they have these sensors in them IF im correct?

LankorDie

I would swap injectors with cylinder 3 to see if the misfire follows. It could be a sticking or bad injector.

eg9_fann

i replaced the injector with 1 from a junkyard....exact same problem...so im assuming the old injector was working fine too

typeR#0427

I would start with a compression test first, then a leak down. Post your results, this will explain alot.

Did you replace the camshaft sensor?

what code is the ECU showing?

eg9_fann

compression was more or less 170 all the way across. the camshafts ensor is in the dizyz i changed it...them codes were due to a bad dizzy.

the way i did the compression was fit the tester in...take all the plug leads off and crank the engine without pressing the gas pedal at all and cranking it about 3 times or so.all other plugs and fuse for FI was still in there places.

iv changed the dizzy and had the timing checked.

car doesnt throw any more codes.


all i can say is the electrical signal to the 1st injector is intermittent.so its either bad wiring (had new engine put in) or dry joints on the ecu? i left the car with a seized engine covered in snow for a month or so.no water leaked in or anything but we did have a bad winter.

all my hopes now rely on on the faulty ecu or faulty wiring? if compression was equal all over the engine must be ok....and if the engines ok sometimes then it cant be an intermittent engine problem as when engines mess up its always 1 way..n thats down hill.lol.

am thinking it has something to do with voltage stabilizer or something....? because sometimes the car is totally fine and something triggers that electrical impulse to stop a few minutes after idle.

current in the system changes at idle as opposed to whilst driving where current is always strong and continuous.

its at the idle....like when your fan kicks in..your idle jumps then adjusts due to the change in electric current.....

sometimes it just jumps (the idle, a tiny bit) then it starts misfiring.then i drive...and it goes ok.i guess il check the alternator and battery readings too.and the reading on the injector wire when its working and not working.

am baffled.

eg9_fann

ok iv had it fixed....new intake manifold gasket..and the water pipe underneath it that goes to the oil cooler was torn and that was throwing presusraized water under the intake mani which i guess was seaping through and making it mis-fire.

started it today and it sounded sooo much better even the exhaust tone felt sharper and engine seemed quiter,

could hear the injector ticking on overtime before too throwing extra fuel where these was mis-firing and that noise has gone away too.

gonna get the acre back tomaorw as im having rear mount/282 brakes sorted next...also had timing belt/water pump/tensioner put on.

cant wait.!