misfire in a KA24DE

[kumanchu]

at leats i think its a misfire; at idle the engine rocks in the engine bay enough to shake the whole car, sounds like an american 8 too.

this weekend i decided to do some checks;

used a spark plug tested (light that goes between plug wire and sparkplug) and it lit up consistently for all 4 cylinders

compression test was fine across the board.

now my friends and i noticed during the compression test that all the spark plugs had a coating of gas on them except for the 3rd cylinder back. so we think it may be the injector.

all the vacume lines were in place, and none seemed to be cracked.

i bought a bottle of injector cleaner adn stuck that in with a new tank of gas. I couldn't afford the 120$ that autozone was asking for an injector. Is my diagnosis correct? and how would i replace my injector? is it as simple as opening the gas cap (to releive pressure) removing the screws/bolts that hold it in and droppign a new one in?

thanks for the help

[kumanchu]

oh yeah; and no funny smells comming from the exhaust when running

[Touchdown038]

After you pull the gas cap, you're gonna wanna pull the fuel pump fuse and crank the engine a few times to fully release the pressure. After that, you're just gonna wanna pull the fuel rail and the injector comes right out.

[DAEDALUS]

Don't do it unless you're pretty sure it is the injector. First of all, with the car running, disconnect the #3 cylinder wire to see if the car gets much worse or about the same. If you can narrow it down to the cylinder, then continue checking the injector. First measure the resistance of the injector. Should be 10-14 ohms I think. If good, then check for current. You can buy a "noid light" which is similar to your spark plug tester, which you plug into the harness and it lights up under injector current. This might all sound like a PITA, but nowhere near as much as is buying and installing parts you don't need.

[NISTECH]

:Werd

I am with DAEDALUS. test and isolate the problem first . replace only the part needed, if any are needed at all. Save time and money that way

[kumanchu]

where do i get a noid light?

[DAEDALUS]

A lot of auto chain stores will have them. A set like this is good, though Nissan isn't listed:http://www.thetoolwarehouse.net/shop/TA-36310.html

[NISTECH]

i got one from auto zone for a GM vehicle. it works on nissans. since they dont have nissan noid lights.