BACKFIREING????

[sliden]

I have a 1990 nissan 240sx and iv got a backfire problem, i think, its more of a popping sound and its coming for my exhaust. It dose it first thing in the morning when i go to work and even after it is wormed up too!!! Then im just trying to drive it down the street it will jerk a lil also. I don't know whats wrong with it, I was told to check my fuel pump and its fine and im wondering if it mite be my catalytic converter and if it is can i just go aftermarket and it be OK??????? PLEASE, IF ANYONE CAN HELP ME

[newton240sx]

well idk why it jerks when your going down the road but its backfiring because you dont have the right back pressure. if its the stock exhaust then somethings wrong and it is normal to have a little bit of back fire everyonce in a while but if i were you id just buy a new exhaust

[devlmaycry]

Ok, "backfiring" is typically from too much uncombusted gas reaching your exhaust and detonating there vs. your combustion chambers. The first things to check are usually: plugs, cap & rotor, wires, timing, air, and fuel. Typically your plugs will be showing wear if your getting incomplete combustion, as well as a gas smell in your exhaust.

That's real basic, but I'm sure the vets and pro's will chime in soon enough to help you. Good luck and check into your plugs and search for plug diagnosis. That should help you get an idea of where to go from there.

[liquid_cool]

well idk why it jerks when your going down the road but its backfiring because you dont have the right back pressure. if its the stock exhaust then somethings wrong and it is normal to have a little bit of back fire everyonce in a while but if i were you id just buy a new exhaust

back pressure ...i have none!..the backpressure arguement is over man...i sugest reading "Project car magazine" article on the whole subject...keep it slideways and hope to see more post's from you at another time.

this is what should be looked into:

your getting to much fuel..and its igniting on your manifold or in the cat...you should ohm test your injectors#1..then test your MAF#2..and replace the O2 sensor..its cheep anyways and probly needs a new one $15.bucks or so....#4. check your FPR..see if its dumping extra fuel throu the vacume line...if non of the above are it...then change out your injector seals...post back with what ya find..thanks