280zx spark issue

[ZedZillaZ32]

Hi guys

Had my 280zx a while now and its always had the same problem to various degrees.

I bought the car and it was running on 5 cylinders tested this by pulling all the injector connectors off one at a time to see which one didnt affect the idle of the car.

found that by swapping spark plugs it just moved the problem to different cylinders till i made it work and all 6 ran, boy was that sweet.

It soon dropped back to 5 so I went out and got all new top notch plugs and lines ran great as a daily driver for about 3 weeks then one day I turn it over and it idled worse then ever!

Started pulling plug leads to find that only 3 of the cylinders are working now.

I dont have the money to keep changing plugs every 3 weeks so any ideas?

cheers guys

[icice9]

id double check your injectors.. insted of just pulling off the connectors and plugging them back in, Get a long screw driver and place the tip anywhere on the injector your checking, then put your ear on the but end of the screwdriver. if you can hear a loud ticking then that injector is firing correctly.. this is a more acurate way to test your injector then just unplugging and plugging it back in... if all of the injectors are fine then id sudgest you check your cap and rotor..

[evildky]

yup check the onjector connectors, it's a common problem, and when you changed the plugs how did they look? are you fuel fowling? coolant? oil? if you're fuel fowling then the spark is either weak or you injector is pouring the fuel in, if it's coolant you have a blown HG, if it's oil could be bad stem seals or bad rings

[ZedZillaZ32]

Its not the cap because I have a sweet running manual spare and I swapped everthing from that into the auto from the coil to the plugs with no luck.

I will try the screw driver thing but i dont think this would help because the problem jumps when you move plugs around.

cheers

[ZedZillaZ32]

plugs and quite black, my mate said they look like its running rich any way to fix that?

cheers

[evildky]

all the plugs looked the same? is the head temp sensor hooked up?

[cpt jack]

all the plugs looked the same? is the head temp sensor hooked up?

If thats not hooked up ur car will litterly sounds like a american car and it will back fire have non stop black smoke.... easy way to tell.... and as injectors go u can just put ur finger around the injector and feel them pulse....

[evildky]

your finger isn't sensitive enought to detect one injector on an engine especially if it's stumbling, just do the screwdriver trick, and for the temp sensor, on the turbo's it's located in the side of the head between the spark plugs for 5 and 6 I believe, on the na's it's located in the lower thermostat housing, it's the sensor with 2 wires, if it's bad or disconnectted the cpu thinks the engine is cold and keeps pouring in gas, if it starts well when cold and deteriorates once warm this is a likely cause