Misfire problems...

[Imprezaman201]

Hey guys i'm new here. I have a 2001 Black RS. i just had a new shortblock put in cause i kinda fried the other one. anyways, i have a weapon R intake lightweight crankpulley sti headgaskets and a racing cam grind. My car keeps throwing missfire codes on all four cylinders. i have no idea what is causing this. i was told that it was because of my cam grinds but i was getting misfire's before i put the new block in, which i when i did the cams. any idea's?

 

[Shorty]

Hey, I know you, this sounds awfully familiar. Let me do some checking on the Subaru Technical Information System(STIS). I take it your getting codes 301,302,303,304? I'm on it.

 

[Shorty]

Ther is 5 pages of tests to run. Are you getting any other codes such as: P0106, P0107, P0108, P0116, P0117, or P0125?

 

[rallyXcramps]

Things that will cause misfires on N/A engines...

* platinum spark plugs, I know, I was having misfires and removed the Bosch Platnums someone put in there for some reason.

 

[Imprezaman201]

well i went back to stock plugs( i had the splitfire +4's in) a had my aftermarket plug wires replaced with stock ones. i'm not sure what the code numbers are that i'm getting, but its misfire on all four cylynders. plus all i run is 93 octane anyways. i got about 800 miles on my new engine and i'm gonna have a checkup done when it hits 1000. the only thing that gets me is it was happening right before my engine blew. a couple of weeks before that i went thru a set of head gaskets and put in new valves and fount that the sti gaskets fit. but once i had my new block put in me and joel found out that they were .006 thinner than the stock gaskets. while in theory is great having the comprerssion ratio raised, could it have caused any problems?

 

[Shorty]

I'm leaning toward a bad coil after looking at the first couple of pages. I'll help you out on the side. We should work out a night to check it out. Monday's are usually good for me, just not this monday. $12 tickets at Shawnee Peak are callin mah name.

 

[rallyXcramps]

You were getting it before the new block?

You put in new valves?

 

[Evan]

if your cams have a crazy grind with very little vacuum being made at idle then that could cause a misfire. it wont misfire at higher rpms where the cams are in their sweet spot, but since you're cel doesn't say the rpm it happened at, it probably happened at idle. fyi, a misfire code code happens when there is a misfire more that 20% of the time.

 

[Shorty]

The cam grinds he's running are the same as Eckjay was running. I'm wondering, the CAI, how long was that installed before the mis-fire started? Did the mis-fir happen before the STi headgaskets or after? I've got a list of stuff to test.

 

[Shorty]

Dooode, we're gonna have to get this thing in and run some tests. I may need to keep it overnight for observation

 

[junkyardgabe]

how did it go at the shop today?

 

[Imprezaman201]

I think that we've got it pretty narrowed down. I brought it down to evergreen today for the 1000 mile check up. they rand the codes and it came up p0301, p0302, p0303, p0304. They said that the engine was runnig good, no problem, and that i could finally open it up. i was a little hesitant at doing that but i still brought it to about 5000 rpm. so i played with it all the way to work, (bout 1/2 hour) and the engine light did not turn back on. when i let my car warm up for lunch. it turned on. so i'm kinda convinced that it is def the cams causing mifire at idle. but i still want it fixed. so does anyone know of the closest place that can tune subaru's?