missfire

[dsmrcer41]

i have a 98 eclipse (auto) with a rebuilt motor and head after the build the car was quick but after 2k miles the ecu went out and i replaced it along with it i put a ram air and header but the car just hasnt been the same it mssfires at around 4k rpms and upward its a lot slower and some times the check engine lite flashescomes on but when it does i just undo the batter cable and the check engine lite goes off but when i stat it for the first time after i undo the cable the rpms go down to 200 and acts like its going to die but the maintains a regular rpm status after about 5 seconds i the check engine lite code reads random cylinder misfire from all 4 cylinders... so if anyone knows i need help

 

[Shadow98]

The coil pack would be my starting point.

 

[jessdogg]

I would check for vacuum leaks and the fuel pressure.

 

[BigRand]

plus one for spark related illness.....check the gap on your plugs, and test the wires and coil pack for continuity....using a multimeter

 

[dsmrcer41]

i replaced the wires plugs and coil ...??

 

[Locke]

What plugs and gap are you using? Where does your vacuum rest at idle? @2000rpms?

 

[dsmrcer41]

NGK irdium .035 ,now its getting worde like a loss of fuel pressure some times it cutts out i though mayb a fuel pump but it was my fuel pump it would do it all the time and not just ometimes rite??what about a fuel filter

 

[Shadow98]

Just get the regular (NGK) copper plugs. It could also be the fuel filter, I think they're supposed to be changed every 60,000 miles.

 

[BigRand]

Run the NGK BKR6ES-11's and run them at the .40 gap, or sligtly less.

I"m not one to ever really reccomend a fuel injector cleaner, but if your going to give it a shot, use the lucus fuel injector cleaner.

 

[dsmrcer41]

i put a new fuel filter and 4 new injectors ### now?

 

[Shadow98]

And the plugs..? Did you go back to regular copper plugs? Check the resistance of your wires to make sure you didn't get bad ones and if you have a friend with another 420A DSM swap coil packs to see if that helps.

 

[dsmrcer41]

i have a new coil pack

 

[Shadow98]

Just because something is new, it doesn't always mean it's 100% functional.