Car Running On 5 Cyclinders Needhelp Asap!

[gtst7]

hey I have a problem with my r32 gtst skyline... it's running on 5 cyclinders atm...

first I thought it was a coilpack that was stuffed but after changing it with another coilpack it didnt change anything. then I changed the spark plug but that didnt help either... the only thing I can think of now is the plug connected to the coilpack? could that be it? if so how do I change that plug?

any suggestion would be helpful

thanks

Edited July 19, 2006 by gtst7

[QRI05E]

Are there any other symptoms such as Smoke? Backfiring? Etc

Take it to a good mechanic and let him test the following:

1. Cylinder compression

2. Injector pulse

3. Coil pack harness

It’s a process of elimination from the smallest cause of the problem to the biggest… could be something real small causing this issue so don’t stress just yet…

Keep us posted

Regards,

Sarkis

[mad082]

when you say you changed it with another coilpack do you mean changed it with a spare coilpack? there is always a chance it was dead too. best way to check if it is the coilpack is to get another spark plug (a spare one that you know works) and 1 at a time pull the coilpacks out and plug the spare spark plug into it and get someone to start the car. make sure there is no light so that you can see if it sparking. this will both test the coilpacks and the spark plugs. if you disconnect 1 coilpack and it doesn't make it run any worse, but the plug sparks then you know its the plug. if it runs the same and the plug doesn't spark then you know its the coilpack. and to make sure it isn't the wiring harness plug swap it with another coilpack on the engine and see if it sparks from that spot. if you can put any coil onto that plug on the loom and it doesn't fire then you know its either the loom or the ignitor.... or possibly the ecu.

[sinistaGTR]

mine was running on 5 cyls.....it was bad news but, like blown turbo and piston rings

[gtst7]

well I'm 100% sure it's not a coil pack... all I can think of is that plug on top of the dead cyclinder is not working...

for example if cyclinder one aint working because of the coilpack plug... and I took the plug out of the coilpack 2 and shove it in the coil pack 1 should it work? cause I've tried doin that and the cyclinder still not working... so now I'm really not sure what's wrong

[MerlinTheHapyPig]

3 things to check...

1-check that it's sparking

2-Do a compression test

3-Check that the injector is firing. (never tried this on a skyline, but i've done it on other cars, you can hold a screwdriver against an injector, and listen through the handle end and you should be able to hear it firing... Might be a problem trying to do this on RB's because injectors are hard to get at due to the intake manifold.)

Edited July 19, 2006 by MerlinTheHapyPig

[gtst7]

how do I check those things?

well all I know is in the dark u can see spark coming from the coilpack when I pull it out of the sparkplug...

[mad082]

for example if cyclinder one aint working because of the coilpack plug... and I took the plug out of the coilpack 2 and shove it in the coil pack 1 should it work? cause I've tried doin that and the cyclinder still not working... so now I'm really not sure what's wrong

you are talking about the plug of the wiring loom, not the spark plug, right? no it won't work. it will make it fire at the completely wrong time. if it is number 2 that you think is not firing then swap the coil with number 1, then leave the coil that you put into number 1 unplugged. if it runs the same (dropping 1 cylinder) then you know its the coil. if it runs worse (dropping 2 cylinders) then try swapping number 1 and 2 spark plugs (so you now have the coil and the spark plug from 1 in 2, and 2 in 1). now start the car again. if it is only dropping 1 cylinder then you know its the spark plug. if its dropping 2 cylinders then you know its the wiring loom.

[mad082]

well all I know is in the dark u can see spark coming from the coilpack when I pull it out of the sparkplug

where abouts on the coil?

[MerlinTheHapyPig]

how do I check those things?

well all I know is in the dark u can see spark coming from the coilpack when I pull it out of the sparkplug...

first of all, determine which cylinder is out. This is done by unplugging the coil pack lead for each cylinder in turn and see if the engine revs change. If the engine revs don't change, then you just unplugged the cylinder that isn't working.

spark

-------

remove the coil pack, put a screwdriver end on the terminal, and hold the screwdriver near a bare metal part somewhere on the car, you should see a spark jump. Or alternatively, you can take out the spark plug, connect it to the coil pack, and it should spark (i think you may have ground the spark plug for it to work)

compression

--------------

buy a compression tester gauge. Or borrow one

with engine at operating temp....

-start car

-unplug fuel pump (plug in boot of car), let car die. This disables fuel pump & re-leaves fuel pressure

-remove all 6 spark plugs and coil packs & crossover pipe, cover etc.

-for each cylinder

- screw in comp tester (make sure you get the ones with the rubber hose on them)

- crank engine 7 or 8 times with throttle to the floor

- record reading

if compression is less than 127psi, or there is a variance of more than 10-15psi (pay particular interest to the cylinder is not running), this indicates comp problems. Do the test again, but add 10ml of oil to each cylinder. Record the results for both tests, and post them up on the forum.

Low compression is bad, it indicates internal engine problems.

fuel

----

Never done this on skylines, but you can try it. Hold a screwdriver against the fuel injector for the cylinder that isn't running, listen through the handle, see if you can hear the injector firing. Compare what you hear to another injector.

Injectors on skylines are hard to get at, because the manifold loops around the fuel rail.

Anyway, if a cylinder isn't running, there are only 3 general causes... Fuel, Spark or Compression. These are the 3 things a motor needs to run.

[gtst7]

I'm pretty sure it's the wiring loom how do I change just one plug? the plug that connects to the coil pack that is.

[mad082]

the only way to change the plug is to either get a whole new loom, or cut the plug off and join a new one on.

[gtst7]

so just hot wire it in?

does anyone have a diy with pictures of how to change an injector?

[sinistaGTR]

have fun with changing injectors....its f#*ked