wierd miss fire, please help

[eastcoastchaos]

my car is running kind of bad. every now and then i put down the clutch about to shift and i hear a wierd pop, i've even seen it shoot fire before. this never happened untill i got my exhaust what can i do to fix it.

[PapaSmurf2k3]

Well, either you dont have a cat, or its totally roasted, or your running way too rich, or your timing is off, or a combination of all. Did you ever think that shooting flames was just cool and that you should leave it alone?

[eastcoastchaos]

hell yeah fire rules but i'm almost sure it is not supposed to happen. no i don't have a cat but what can i do to fix it. i've heard you can roast your valves w/ the fire shooting and what not. it has not been like this for too long but what are the chances my valves are screwed to.thanks

[red240ne]

Ha, don't leave it alone actually. You're runnin lean and your timing is probably retarted. You can lost a lot of HP from these factors. Might sound cool, but I'm sure you would like the power gains back.

[eastcoastchaos]

indeed i'll take what power i can get but how can i fix my little problem. can i just do some adjusting or do i need to drop some cash.thanks for the help

[red240ne]

Replace your 02 sensor if it's old. Look in the FAQ section of 240sx.org to find out how to adjust your timing.

[KSee777]

how can he shoot fire but run lean?

[themadscientist]

stop, wait a minute, do you have a blow off valve that releases to the atmosphere? If you do it's going rich for a second when you shift because metered air is escaping out the blowoff but the fuel was already sent, thus the pop. The reason it "appeared" is because you put on a big exhuast with no cat, you just couldn't hear it before. My wife's 180SX does the same thing but when it pops my A/F meter swings to about 10:1 for a second, you are fine.