1998 VT v6 only firing on 4 cylinders

[greg130]

Hi Guys,

Need a bit of advice please.
Looking at buying a 1998 VT v6, done approx 300,000 km's, seems in good condition but only firing on 4 cylinders.

No spark from the passenger side coil (1+4?), owner says he has changed plugs, leads and coil.
He suspects the CAS? If this was the case would it just affect one of the coils or all coils?
I'm hoping its the DFI but could do with some guidance.

All input welcome guys :-)

Cheers

[greg130]

Update, apparently not the DFI as this has been changed.
Would a faulty CAS cause the lack of spark on 1 coil?

[acarmody]

Tried swapping the bad coil for one of the others and seeing if the non-firing cylinders change?

[greg130]

Tried swapping the bad coil for one of the others and seeing if the non-firing cylinders change?

Yeah apparently thats allready been done, thanks anyway.

[SBM]

Try it yourself just incase. I never go by what someone has apparently done. I'd also check the wiring plug on the DFI I've seen a few with a bent pin causing all sorts off troubles.

[Hangman]

Try it yourself just incase.

This, for all of the "done" things...

[greg130]

Easier said tha ndone guys, can't really start stripping someone elses car down.

I have no reason to disbelive him, he has replaced the DFI, coils, plugs and leads, infact he showed me all the old stuff.

So the question is can a faulty CAS cause one of the coils not to spark?

[Hangman]

From experience, I would say no, it just makes it crank but not fire, mostly when hot. That's not to say it can't happen, I'm not a mechanic.

I'd still check the coil packs. New stuff can be faulty.


And if this is all on a car your looking at buying, the price should be adjusted accordingly. I know I wouldn't buy a car based on how it should run instead of how it does...

[greg130]

Thats my conern, if the CAS is faulty then would it stop all the coils from firing? If its not the CAS then what is it?

Yeah the car is priced accordingly, 2k asking price, think we might give it a miss as I fear there is more wrong with it than meets the eye?

[Cameron P]

move the coils around and use plyers with rubber handles and pull the leads off... should tell you what is wrong with it exactly

[Cameron P]

call me stupid but what is 'CAS'?????

[Hangman]

Crank Angle Sensor, mate

[acarmody]

"Crank Angle Sensor"

EDIT: Damn, ninjaed by Hangman.

[Hangman]

"Crank Angle Sensor"

EDIT: Damn, ninjaed by Hangman.

I don't reckon 2k for a vt on 4 cylinders is accordingly priced either...

[accentstencil]

call me stupid but what is 'CAS'?????

Edit: I answered much to late so disregard this post.

[Tsunamix]

I know youve said it's not but it MUST be coil or DFI. DFI triggers coil, coil fires and sends spark to 2 cylinders at same time.

If it was just 1 cylinder or 3 then it could only be DFI, but being 2 it must be coil or connection between DFI and coil. Try cleading the spade terminals of the DFI.

If its a dud DFI, swapping coils around wont change anything. If it's a dud coil, changing the coild around will mean a different pair of cylinders loses spark.

[FstStig]

Agreed, It can't be anything else only the Dfi, Coil Packs, Spark plug leads and Spark plugs create the spark, could check the DFI plug and wiring.