car missfiring 1995 vs v6

[carpetsnake]

as it says my 1995 vs v6 is missfiring well i think it is. driving a long then it misses .i have just changed the crank sensor,cam sensor,and the 2 oxygen sensors.any ideas what is causing this.was doing it before all the new sensors.could it be the thing under the coils the dfi sensor.i think thats what it is called and has new sparkplugs as well .

[eurekamad94]

any specific rev range ???

[carpetsnake]

no just driving normaly around the streets at 50 km hour and other speeds

[greenacc]

could be a coil or the leads. Does it miss under load when you put yur foot down ?

[carpetsnake]

yes and when it is at a stable rpm coasting

[greenacc]

how old are your leads ? have a good look at them for any deep rub / burn marks on em that will cause a miss. you might be able see sparks from the leads or coils if you watch it idle / rev in the dark, worked for me when it was my coil

[WAC-988]

im having the same sort of problem with my 98 vs
if happens after a while driving like 20 mins
at sometimes its at 3-4 k
and sometimes a 4-5 k
every time it does it is ****es me off!!!

[carpetsnake]

wi;ll replace leads and dfi modual and do the coils as well wont hurt

[kopper69]

You can first narrow it down to which cylinder is not firing. You do this by disconnecting the connector on the injector while the car is running, one at a time. When you disconnect the injector petrol is no longer injected into that cylinder and the car will instantly change the way it is running. This will happen on all cylinders EXCEPT the faulty one. As the faulty one is not firing the engine will not change at all.

Once you know which cylinder is not firing you can check a couple of things.

Coil packs. You can measure the primary resistance and secondary resistance. Primary is on the bottom of the coil. You need to remove the coil and measure the resistance between the two connectors on the coil. You should get something around 0.6ohms.

To measure the secondary you measure between the two connectors on the top of the coil that you would normally connect the spark plug leads on to. The resistance should be between 5 and 7 kilo ohms (5000 to 7000 ohms). I have found coils to be around 8kohms and they will not fire, causing this bad idle.

But definitly start by narrowing down the cylinder. You can also check that the spark plug doesnt have any gunk on it that would stop it firing.

New coil pack can be purchased for around $55 from repco or around $75 from holden, $100 for some MSD coils (claim to be a little better). Even cheaper if you went to the wreckers.

Let us know how things go.

[kopper69]

im having the same sort of problem with my 98 vs
if happens after a while driving like 20 mins
at sometimes its at 3-4 k
and sometimes a 4-5 k
every time it does it is ****es me off!!!

mate your problem might be the spark plug leads. Start by replacing them. What you have is a breakdown under load.

[carpetsnake]

finally fingers crossed it is fixed
after 1 cam sensor/1 crank angle sensor.1 dfi modual/2 oxygen sensors and 1 coil pac
it was the coil pac
running real good now doesnt miss a beat touch wood
i will get the other 2 coil pacs when i get more money
this forum is so good i will be asking hear first before going to the machanics from now on

[mrhotdog]

these people prob know more than some mechanics do :P

[carpetsnake]

the stupid thing is still cutting out not miss firing any more
stalling while driving i dont know why running perfect then it like it turns off
starts straight away ????????? help i am going insane trying to find out why

[kopper69]

Not sounding good. Have you checked error codes?

[greenacc]

bugger ey, solve one problem get another. Was it cutting out before all this work or is that new ? I can only guess that the cutting out is DFI related or a loose connection/damaged wire in the dfi harness somehwere. check the codes as kopper said, there should be a code or 2 logger after all this.

[Ozzie]

Just a tip... may or may not solve the problem.

Change the leads and plugs, If it is still missfiring... check the coils arent loose.
Sometimes the bracket the coils sit on can loosen.

[carpetsnake]

auto electrication thinks it is the crank sensor so getting another put in tomorrow
running nice now only turning it self of when driving
the crank sensor i got the first time was a cheapie off ebay the car ran fine for 6 weeks then started turning its self of when driving so getting a top quality one this time
hopefully this works .

[fuzzy2308]

let us know how you go

[carpetsnake]

had another crank sensor put in it seams to be running fine not cutting out so far
so i learnt a lesson dont buy cheap parts from overseas buy a decent brand like bosh