Misfire.. Help

[lauj2gdsm]

Ok.. My car been running really crappy lately.. misfiring during start up.. then when it warms up it gets a little better then throw p0300 (random misfire) and PO301 ( misfire cyl 1) some times it will just choke and die. when i open the hood while its missing firing and press the throttle cable it will hesitate and i will hear a ticking noise by the injector and a air hissing noise behind the intake manifold near the brake fluid before the engine revs up. One of my coil just recently fry too. but heres is the list of what i have swapped already.. ECU, WIRES, PLUGS, COIL PACKS, POWER TRANSISTOR.. but still it runs like crap. Any suggestions on what it can be??? also the car has been parked for near 2 yrs.

MODS,
50trim
fic 650cc ( less than 5k )
fmic
3" catback
walbro 255
intake+bov ( circulated )
Ecu+

 

[spyderturbo007]

RM CEL's are a pain to diagnose. It looks like you've addressed some of the most common problems associated with RM's already. What plugs did you use and what was the gap?

Also, you might have a stuck / dirty injector. You can normally get an idea of the injector status by putting your ear to the end of a screwdriver and placing the metal end on the injector. Then listen for a consisten tick from each injector. It's possible that you have one that isn't opening properly.

Are you using the gas from 2 years ago, or did you drain the tank and fill up with fresh? Might also be a dirty fuel filter.

 

[lauj2gdsm]

plugs are new and are gaped properly. been driving the car for over 2k so gas is always new.. hm.. i need to check what you mention about the injectors.

 

[turboglenn]

Could be a crack in the head or a bad head gasket as well. i've seen both show no other signs than mis-firing nd fouling plugs here and there. First time i pulled the head there was a crack between 2 valves. The second time it was a blown head gasket between cylinders 2 & 3 . Do a leakdown test and compression test, that should tell you if it's deeper in the motor or something external or wiring related.

 

[DirtyBirdRacing]

Hi,

The air hissing noise means that your engine is sucking air in from somewhere that it isnt suppose to. Do a boost leak test and compression test to see where the hissing is coming from. A large vacuum leak could cause a misfire upon start up, espically in the cold. It would be a lean misfire. That means the engine is sucking in so much air that it is seriouslly upsetting the air/fuel ratio upon start-up. The air fuel ratio upon start up, espically in cold weather, is extremely rich due to the fuel not atomoizing and vaporizing well when its cold or when the engines cold. That is probably more then you wanted to know, haha. Hope this helps.

Bill