gas out of exhaust

[BuBBa DRiFT]

before i tell you my dilemma here is my back story:

swapped the motor (KA24DE) and ever since the first crank up, ive only ran on 3 cylinders, did a compression test and i have 175psi across the board. Brand new spark plugs, brand new z32 fuel filter. All cylinders fired consistant except for cylinder #2, you can take the spark plug wire out, and it will not affect the idle. Ran a test, have 12 volts going to every spark plug and my ignition voltage is normal. Decided to change the injector from s13 obd1 to a s14 obd2 injector. The cylinder still didnt fire. Went back and swapped back the injector #2 and decided to examine injector #3 to compare the two. Put everything back and cranked her up.

now on to my problem:

im running so rich gas is coming out of tail pipe...this is new to me, just happened just now, swapped #2 injector back to the old one (s13 obd1) thought maybe the resistance in the obd2 s14 injector might be a tad higher causing not enough fuel to spray, cranked her up, still running on 3 cylinders...so i pulled the spark plug on cylinder #2 and the car almsot died!! (which is good cause now its firing) But now cylinder #3 is doing the same crap that cylinder #2 used to do! and now i got unburnt fuel and loads of white smoke outta my tailpipe!!

whats the dealio?

its obvious im running rich, but why? leaky injector...bad rubber washer..let me knowwwwww!!!

[Gutling]

unbolt the fuel rail (leave all injectors/plugs in it) set a paper towel or something under it, and turn the key to on (where u hear the fuel pump turn on)
This will show you instantly if any of the o-rings are leaking, if there is gas coming out of any of them they are bad.

[BuBBa DRiFT]

unbolt the fuel rail (leave all injectors/plugs in it) set a paper towel or something under it, and turn the key to on (where u hear the fuel pump turn on)
This will show you instantly if any of the o-rings are leaking, if there is gas coming out of any of them they are bad.

good show, repped accordingly

[DirtyMechanic]

You might want to check if the injectors are firing at all. Seems like you got a fuel delivery problem since compression are spark are supposedly good. You probably have a bad ECU. make sure your getting 12 volts to all the injectors and that the ecu is triggering them. if all that shows to be good. swap out with the SAME injectors. i dont know 240sx but i know nissans uses the same resistance injectors. useing injectors from different models are probably not helping you due to the fact they might have different resistances.



oh and the reason that you have fuel coming out the tailpipe... you have a misfire. which means you arent buring fuel... which then gets pumped out the tailpipe

[AnthonyF]

^x2. Maybe take it to a professional and get them to hook a computer to it and see whats wrong.

[Elbow]

Make it shoot flames

[Z U L8R]

dirty mech knows whassup.

there's a technical service bulletin aka TSB (information the car manufacturer releases when a certain problem happens to a couple people with the same thing being the culprit)

there's a TSB about the "front engine" wiring harness aka the engine harness that goes to all the sensors on your motor then through the firewall to your ecu

the tsb talks about the wiring harness and having bad connections especially to the injectors. basically inbetween the firewall and the intake manifold (on the passenger side), a little before the harness branches out and goes to all 4 injectors, it corrodes, or gets brittle, or makes bad connections where the 12volt power supply to all 4 injectors, starts off 1 wire, then has the little metal crimp connection and has the 3 or 4 other wires crimped to it right there to distribute the 12v to each injector.

basically here's an easy thing you can do.

get a regular plain jane test light or a low voltage circuit safe test light.

start your car, unplug the injector plug from the cylinder that's misfiring at the time, whether it be cylinder 2 or 3.

take your test light and connect it to a ground or the negative on the battery. probe the 2 pins on the injector plug. if neither of the pins make your test light light up then you know the injector's not getting any power, try wiggling the wiring harness and see if it lights up. find your bad connection and repair. if your test light lights up and it stays lit when you jiggle the harness in different places then getting power to the injector is not your problem and continue to step 2

now take your test light and connect it to the POSITIVE terminal on the battery because now we're searching for a ground.

probe the other wire on the injector plug and your test light should flicker. this is called "noid" signal. the ecu gets it's reference from the cam angle sensor that's built into your distributor and knows when to send these ground pulses to each injector thus making the car run. if your test light is not flickering, try wiggling the engine harness in different places and see if you can get it to flicker, if it does then repair the connection in the harness. if it still refuses to flicker then look up a KA ecu pinout and identify your injector #3 or #2 (whichever one's not working at this time) signal pin. with your test light still on the positive, poke through the injector #3/#2 wire and see if you're getting a ground pulse at the ecu. if you are then your ecu is good, and somewhere from the ecu to the injector plug the wire is broken. you can run your own wire from the ecu to the injector plug (the "shadetree" way) or you can probe that signal wire going further down the harness closer to the injector plug and when you get to a section where before you had ground pulse, and now you don't, then you know your problem is in between those 2 points. repair harness.

if your test light doesn't flicker when you probe the injector signal wire at the ecu then either your ecu plug is not in all the way/jacked up/cocked to the side, or you have a bad ecu, try known good ecu and continue.

you should come out to roswell and lemme fix it ^_^
gl,
Dave =]

[AnthonyF]

^z u l8r deserves multiple rep points from everyone. always willing to help.

[Z U L8R]

reps or strawberry candies will do just fine @@!

Dave =]

[BuBBa DRiFT]

zul8r, i already tested for voltage, im getting 12 volts to every injector lol, thats not the problem!!!

oh, and the plug had black dry soot, so it IS getting fuel

[Z U L8R]

ok so it's getting 12volts, is it getting the ground from the ecu though?

[TS240]

Make it shoot flames

x2 lol
OR take it to Dave he could probably fix it in like 2 min.

[AnthonyF]

reps or strawberry candies will do just fine @@!

Dave =]

lirl, you LOVE 1-800 radiator. I wanted to take a pic of our baggie and post it. Next fresh bag i will, along with the notepads.

[DirtyMechanic]

dirty mech knows whassup.

there's a technical service bulletin aka TSB (information the car manufacturer releases when a certain problem happens to a couple people with the same thing being the culprit)

there's a TSB about the "front engine" wiring harness aka the engine harness that goes to all the sensors on your motor then through the firewall to your ecu

the tsb talks about the wiring harness and having bad connections especially to the injectors. basically inbetween the firewall and the intake manifold (on the passenger side), a little before the harness branches out and goes to all 4 injectors, it corrodes, or gets brittle, or makes bad connections where the 12volt power supply to all 4 injectors, starts off 1 wire, then has the little metal crimp connection and has the 3 or 4 other wires crimped to it right there to distribute the 12v to each injector.

basically here's an easy thing you can do.

get a regular plain jane test light or a low voltage circuit safe test light.

start your car, unplug the injector plug from the cylinder that's misfiring at the time, whether it be cylinder 2 or 3.

take your test light and connect it to a ground or the negative on the battery. probe the 2 pins on the injector plug. if neither of the pins make your test light light up then you know the injector's not getting any power, try wiggling the wiring harness and see if it lights up. find your bad connection and repair. if your test light lights up and it stays lit when you jiggle the harness in different places then getting power to the injector is not your problem and continue to step 2

now take your test light and connect it to the POSITIVE terminal on the battery because now we're searching for a ground.

probe the other wire on the injector plug and your test light should flicker. this is called "noid" signal. the ecu gets it's reference from the cam angle sensor that's built into your distributor and knows when to send these ground pulses to each injector thus making the car run. if your test light is not flickering, try wiggling the engine harness in different places and see if you can get it to flicker, if it does then repair the connection in the harness. if it still refuses to flicker then look up a KA ecu pinout and identify your injector #3 or #2 (whichever one's not working at this time) signal pin. with your test light still on the positive, poke through the injector #3/#2 wire and see if you're getting a ground pulse at the ecu. if you are then your ecu is good, and somewhere from the ecu to the injector plug the wire is broken. you can run your own wire from the ecu to the injector plug (the "shadetree" way) or you can probe that signal wire going further down the harness closer to the injector plug and when you get to a section where before you had ground pulse, and now you don't, then you know your problem is in between those 2 points. repair harness.

if your test light doesn't flicker when you probe the injector signal wire at the ecu then either your ecu plug is not in all the way/jacked up/cocked to the side, or you have a bad ecu, try known good ecu and continue.

you should come out to roswell and lemme fix it ^_^
gl,
Dave =]

ugh was to lazy to type all that out. but yes +1^^^^

if you cant figure it out let someone that knows out to basic di-ag look at it.

[BuBBa DRiFT]

ill test the ground, but im just gonna try and replace the injector, i think i ****ed up the o-ring, since it was working before i cant imagine it would just stop working, after i inspected it (or in the process of removing it, the o-ring probably got tore or something of that sort

[DirtyMechanic]

ill test the ground, but im just gonna try and replace the injector, i think i ****ed up the o-ring, since it was working before i cant imagine it would just stop working, after i inspected it (or in the process of removing it, the o-ring probably got tore or something of that sort

what o-ring are you talking about? the one the seals the injector to the manifold? or the injectors to the rail. because if either was a problem then youll either have fuel spraying/pooring out all over the place from that injecotr or have a vacuum leak...


why dont you do this start the car up and put a large screw driver or a mechanics stethoscope on each injector to see if you can hear each one clicking and working. thats one quick and easy way to check to see if the injector is firing

[BuBBa DRiFT]

im doing that before i rip off the fuel rail, forgot to mention it

[GSRteg®]

Make it shoot flames