njdrsubaru Posted November 28, 2011 Share Posted November 28, 2011 it usually happens when i first start in the am or after a drive it misfires for about 45 seconds and it idles fine now i have already replaced the following: plugs, wires, coil, ignitor, injectors, fuel pressure regulator, fuel pump im out of options Quote Link to comment Share on other sites More sharing options...
95legwagon Posted November 28, 2011 Share Posted November 28, 2011 maybe 02 sensors? howbout knock sensor? just a thought lol -jarrid Quote Link to comment Share on other sites More sharing options...
njdrsubaru Posted November 28, 2011 Author Share Posted November 28, 2011 o2 and knock wouldnt have a misfire symptom it could run a bit lean or rich but not misfire like it is now how about the AIC? Quote Link to comment Share on other sites More sharing options...
davebugs Posted November 28, 2011 Share Posted November 28, 2011 If those were all quality parts I've seen coolant temp sensors cause this on other (non Subaru) cars. Quote Link to comment Share on other sites More sharing options...
njdrsubaru Posted November 28, 2011 Author Share Posted November 28, 2011 i was thinking about that CTS... Quote Link to comment Share on other sites More sharing options...
davebugs Posted November 28, 2011 Share Posted November 28, 2011 i was thinking about that CTS... Often a good operator with the fancy Snap-on scanner can check that reading to see if it's out of whack. Don't forget there are 2 coolant sensors, one for the ECU and one for the dash( a spade terminal under #3 intake) it seems. Quote Link to comment Share on other sites More sharing options...
njdrsubaru Posted December 6, 2011 Author Share Posted December 6, 2011 ok i changed the CTS and still doing it now... can a intake manifold gasket do this? Quote Link to comment Share on other sites More sharing options...
naru Posted December 6, 2011 Share Posted December 6, 2011 Yes,but,there would not be enough heat in the engine after only 45 seconds to close an intake leak.Additionally,you mention it also happens after a drive when the engine is presumably warm. I suspect fuel or coolant fouled plugs. Quote Link to comment Share on other sites More sharing options...
mwbean Posted December 6, 2011 Share Posted December 6, 2011 keep in mind that the computer in default mode untill the engine gets to normal operating temp. It is not unheard of to get bad Parts that are "new" I recienty bought a new airflow sensor and it was bad right out of the box... Recheck the conductivity of your wires. Quote Link to comment Share on other sites More sharing options...
njdrsubaru Posted December 6, 2011 Author Share Posted December 6, 2011 it happens after I drive, park and let it cool down a bit then when I try I start it misfires for about 20 seconds or so or until I step on the gas reving it up Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted December 6, 2011 Share Posted December 6, 2011 I'm just going to ask because I didn't see it specifically stated....... how do you know it is misfiring? Is the CEL/MIL flashing? What cylinder(s) does it say are misfiring? Quote Link to comment Share on other sites More sharing options...
njdrsubaru Posted December 6, 2011 Author Share Posted December 6, 2011 no cel... it misfires then if pu rev it up for a bit it stops as it goes back down to idle Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted December 6, 2011 Share Posted December 6, 2011 Maybe it is something other than misfire. I didn't know it was possible for it to misfire repeatedly like that and not throw code(s) P030x. Quote Link to comment Share on other sites More sharing options...
davebugs Posted December 6, 2011 Share Posted December 6, 2011 Maybe it is something other than misfire. I didn't know it was possible for it to misfire repeatedly like that and not throw code(s) P030x. Often is a missfire and no codes it seems to be fuel delivery, timing or valve problem because an electrical issue almost always sets atleast a pending code if not an outright CEL. Quote Link to comment Share on other sites More sharing options...
njdrsubaru Posted December 6, 2011 Author Share Posted December 6, 2011 I just replaced the intake gaskets lets see what happens I'll keep everyone informed Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted December 7, 2011 Share Posted December 7, 2011 o2 and knock wouldnt have a misfire symptom it could run a bit lean or rich but not misfire like it is now how about the AIC? They can, but the O2 will not affect running when cold. Knock sensors typically set codes when they get bad enough to cause misfires. I had a problem with a cold start misfire. It was a bad head gasket. Coolant was weeping into cylinder 4 as the engine cooled down down. When started it might misfire for 5 seconds, 30 seconds, or sometimes not at all. Check your coolant level. Quote Link to comment Share on other sites More sharing options...
njdrsubaru Posted December 8, 2011 Author Share Posted December 8, 2011 ok this is the second day after replacing the intake manifold gaskets and still no sgn of misfire when starting cold or warm Quote Link to comment Share on other sites More sharing options...
njdrsubaru Posted December 9, 2011 Author Share Posted December 9, 2011 doh! it started doing it again today.... im gonna replace the ecu next and see if it gets better.... compression checked in all 4 cyl... im running out of options Quote Link to comment Share on other sites More sharing options...
nipper Posted December 10, 2011 Share Posted December 10, 2011 Nothing wrong with the ECU. If it is always #4 and not throwing a code it can be an injector leaking. Quote Link to comment Share on other sites More sharing options...
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