help, engine running like *@#%

[jarredd]

Hey guys,

My car was running fine yesterday... Then this morning when i turned it on to go to work it was puttering. Just to give you more detail, it was idling around 500-600rpm, shaking bad, and making a puttering exhaust note. It was really weak too, by that i mean unresponsive and slow to get going.

Any ideas what it is? maybe misfire, bad sparkplug...? Any help is much appreciated...


Thanks,
Jarred D

[1slowS13]

you maybe running on 3 cylinders or less.

check if your injectors are pulsing correctly.

also check the ecm for codes.

[mifesto]

yeah check spark plugs and ecu codes first....

by chance u filled the gas up last nite?

[jarredd]

no... didnt fill up.... i will check the codes and the plugs... thanks...

If thats not it, any other ideas??

could it possibly be a loose vac hose?

[stinky_180]

that happened to me before, one cylinder wasn't firing

pull injector harness one cylinder at a time and record engine rpm change. if there is a cylinder with NO change in RPM, you have narrowed down the cylinder.

[pink godzila]

Hey,

I think I have the same problem not sure, my rpm is about 700 bout sometime down to 600 then up... but car dont really shack much. Do you guys think I have the same problem?? Also, see like no power on high speed..

[xsparc]

sounds like a dead cyl, turned out to be 1 bad plug wire

Originally Posted by pink godzila

Hey,

I think I have the same problem not sure, my rpm is about 700 bout sometime down to 600 then up... but car dont really shack much. Do you guys think I have the same problem?? Also, see like no power on high speed..

sounds like you have a vac leak somewhere

[jarredd]

i pulled the plug... it looked decent, not white or oily or broken.... but i replaced it anyway.... still having the same problem... possibly dist cap? or wires???? the wire seems to be firing though.... i hear a ticking from the wire like its firing.....

[xsparc]

ticking from the wire is bad.
start it up and pull the wires from the plugs one at a time. the one that doesnt change how its running will be the bad one. it could also be the cap if you have not changed that yet.

[jarredd]

What does the ticking mean?

As i pulled plugs 1-3 the car gets really rough, and on the 4th it stays the same. So i am sure it has to be the fourth one. I replaced the plug, no change. When the wire is out, it makes a clicking sound when it is allowed to touch something. when i just hold it, no sound.


any ideas....

[xsparc]

its your number 4 plug wire. get a new one.

[oskars14kat]

also, at night, you can spay alittle bit of water in the spar plug wires and see if there is arching, if you see arching replace that wire and you should be fine. if the wire insolator is weak the water will create a path with less resistance and will arc. its an easy way to check for weak wires

[sc ka24e]

if yur spark plug wiring is sparking when grounding to something it is not yyr wires... if u already changed that spark plug then its going to be yur fuel injector on #4 .. check if it is getting power.. if it is test injector .. mine had a bad ground on the wiring and wouldnt fire an injector... GL hopefully its not a dead cylinder...

[jarredd]

damn, just changed all plugs and wires... no difference.

how do i check the injector/injector ground?? hopefully this can be fixed in the next day or so...

also, how can i tell if its a dead cylinder and what can be done to fix?

[SexPanda]

shit that happened to me all the time. 1 of the injectors had a minor short, so i just wiggled them until it ran correct again...

try that.

[nissan_driver24]

rule of thumb when dealing with a misfire like what u're having right now. Check for spark since it's the easiest thing to do first. and since u replaced the wires and plugs and u're still having a problem check ur dist cap maybe it could be damage, you could also check the rotor but most likly its ok since 1 through 3 is still working.

if that's all good then check fuel, since the 1 through 3 cylinders are working properly, then u're getting good fuel pressure now the only thing to do is to check for voltage pulse with a test light or something in that manner even a dmm will work, if you have good voltage pulse then check the injector for continuity i'm not sure what the ohms run for stock 240 injectors but you can check the injector ohms on one of the 1 through 3 injectors to get an idea of what it's supposed to be. if u're not getting the right ohms reading then it's a bad injector.

I think u are having a problem with ur injector being stuck closed but check everything has to do with the number 4 cylinder and ur problem will show itself up.

[xsparc]

what they all say. since you changed you wires and the prob is still there, it could be the cap, but most likely an injector prob.

[jarredd]

how do i perform these tests.... which wires should i be checking?

[xsparc]

first unplug all the injectors and use a multimeter to check the resistance, they should all be the same.. around 14 ohms if i remember right, correct me if im wrong.

next check for a ground on the wiring harness, i dont have a FSM with so you you need to look up that part.

[jarredd]

ok... so i checked resistance on the injectors... 1-3 were at 11 ohms.... the 4th one was reading 2.1-3 megOhms... bouncing around....

I dont have a noid light, but gotta pick one up to check pulse. Could it be a bad/dirty injector....

You think clean it or buy a new one?

[xsparc]

MegOhms means its burnt out. sounds liek you need a new #4 injector

[jarredd]

does anyone know a good place to pick up a new injector? should i get a new set or just one?

[xsparc]

first i would see if a friend had one you can drop in to test with before you go buy some. but you can buy just one if you want.

[jarredd]

where from? i have only seen sets?

[xsparc]

most auto places have them

[NismoS13Chuki]

i cant believe no one recommended this but an easier way to check a injector with out having to unplug this and that is a screwdriver. You just take a long screwdriver place the metal end of it on the back of the injector wrap you hand around the grip in a matter so that you can put you ear up to it and listen to the injector. a good injector will sound like several clicks and you sould be able to hear it very clearly. anything other sounds can indicate a weak injector and no sound indicates a dead injector.

[xsparc]

im just used to doing it my way, i always have a multimeter in the car, but good idea... everyone always forgets the old skool ways

[jarredd]

Originally Posted by NismoS13Chuki

i cant believe no one recommended this but an easier way to check a injector with out having to unplug this and that is a screwdriver. You just take a long screwdriver place the metal end of it on the back of the injector wrap you hand around the grip in a matter so that you can put you ear up to it and listen to the injector. a good injector will sound like several clicks and you sould be able to hear it very clearly. anything other sounds can indicate a weak injector and no sound indicates a dead injector.

thanks!!! I will try that as well!

I truly appreciate everyones help
!

[nissan_driver24]

just go to any auto parts store and they will have one... or get one used from the wrecking yard for free ninety-nine... the old screwdriver to ear is a good trick.... but it sucks when sometimes u're not sure if it is because u can hear the other injectors going on the one u're checking... using the dmm is the only way to go to be 100% sure.

Glad u found the problem jarredd and at least it's an easy fix. My maxima was a pain to fix because i had to take off the intake to replace one injector...

[s13pignose]

Lol glad I wasn't the only one thinking of the screwdriver trick. A mechanic told me about thta, but he had a scope...same principle though.

So what was it bad injector?