My VL's mystery illness

[Sarge777]

Hi Everybody,
I live in Byron Bay and own a VL Station Wagon, made in May 87, a normal Nissan fuel-injected 6 cylinder. Overtaking some trucks doing about 130kph back in early March, I suddenly lost power, all my warning lights came on, and I coasted to the side of the freeway. Such were the symptoms that I presumed I had broken my timing belt. After stripping the motor to find the timing belt was fine, I later sourced the car's onboard computer, and replaced the crank angle sensor. The old girl started first go, and ran beautifully, until it reached normal operating temperature - and then started popping and backfiring as though a fuel feed was the problem, and then soon cut out. It would not restart, but then did so after cooling down for an hour - but then resumed backfiring. I have since had it at various mechanics, and had a new coil fitted, and new leads, but the problem persists. I have now replaced the fuel pump down near the tank, the fuel filter, and cleaned all contacts on things such as the air flow meter, but still no joy. I am at my wits and wallet's end. The car has a straight rust free body and I am loath to give up on her, but where can I turn next? Any suggestions? Thank You! regards, Sarge.

[VH308]

Does it chug black smoke when it pops and backfires? If so it is possibly the MAF. Could also possibly be the coolant temp sensor. Also make sure all your earths are good.

[detox_nath83]

Crank Angle Sensor (CAS) thats what it does... they can go slowly, or fail straight away..
i have a thread on how to change one over....
The Cas is located in dizzy.
If timing belt snaps you would know. smash your valves/pistons etc

Goodluck let us know...

[harry3]

I had the same fault on my 6 cly wagon but being an old timer I immediately checked for any overlong or unsupported rubber fuel hose, as this often kinks shut when it gets warm but reopens later after it cools down

sure enough I found a long unsupported length of hose under the back near the fuel tank and positioned inside a flexible funnel tube and have had no problems since

the reason it was there is holden can no longer supply the original shaped hose section and recommend a long piece of straight hose, but they dont mention the need to support or locate it to prevent kinking from softening by heat, the heat coming back from exhaust system, engine and radiator fan is enough to do it, I guess you will now be kicking yourself

btw many confusing and expensive sounding noises from the auto trans are usually caused by overfilling with trans fluid

[Sarge777]

G'day VH308, detox_nath83 and Harry 3,
Thanks for the feedback and suggestions.
* VH308 - Yeah, there is a little black smoke when she backfires. Pardon my ignorance, but what is the 'MAF'? After it did it the first time, I limped to a mechanic after letting it cool down and restarting it. I parked across the road consulting the mechanic. When I went to restart it to move it over to the mechanics, it let go an almighty backfire 'bang!' and then grey smoke start coming (quite profusely) from under the bonnet. I opened the bonnet and the smoke was coming out of the air filter.
* Detox' - would it still run if the CAS was blown? We put a new one on it at the start of this same frustrating process. (P.S - were you at Bathurst in 2006 with a couple of mates wearing sombreros and maroon coloured Ts with your '24 beers in a carton...' line printed on the front?)
* Harry 3 - no mate, checked for any overlong or unsupported fuel hose and they all seem of proper 'unsaggable' length. By the by, my auto trans' isn't making any noises, but right now it doesn't seem to like changing gears until it reaches certain revs, and it almost redlines before it changes up. For eg, it won't change to top gear until 80kph.
One of my mates in Vico is a VL fanatic, and he's beginning to wonder if I've got the devil's VL. Yikes!

[Nackerz]

yea i had a bad problem with cas , did you change that metal plate too.

i did and still ran like shit put the original metal plate (the one i pulled out ) gave it a clean, with the new cas and runs like a dream.

The cas will cause it to back fire, and if it does run it will run like shit if the cas is stuffed.

Good way to check is pull no.1 lead off stick a screwdriver in it and wind it over see if you get constant blue spark if it sparks orange sometimes and blue other times, stop winding it over and turn the key off and turn it on again and try again, if its orange spark the cas is stuffed.
Try when cold and then try when hot when the problem occurs off not starting.

Note if you changed your cas already as i think stated above, if this one is stuffed and you didnt replace the bearings in the dizzy, this is what would be causing the cas to blow as the bearings throw this red dust shit out of them when there stuffed and it will destroy your cas in the matter of seconds to days


Hope this helps mate i stuffed around for days with mine before i got it right

[Sarge777]

Thanks VLWALKY, I'll give all that a go and come back to yas.

[VH308]

No worries Sarge. MAF stands for Mass Air Flow meter. Have had this happen a couple of time with my bro's VL and a couple of customers. VLWALKY also makes a good point about the dizzy and worn bearings. Another way to diagnose this fault (if it is possible), is to find someone with a VL that has no running problems and swap items such as the air flow meter and dizzy (even coolant temp sensor) until the problem is sorted. This way you are not guessing and buying parts which are not required to fix the problem. Have had to do this before with a couple of VL which did not follow the "RULES" so to speak.

[detox_nath83]

Changing metal disk in CAS will not make a difference. Just making sure it is clean and not put on backwards,with all the slits not having debris in them make sure u can see through them all., all it does is the slits on it are read by the diodes so it knows when to fire and on what cylinder.. the large square hole on it is TDC cylinder 1.. as stated above the red dust from the bearing(the dust/dirt seal gets brittle which in turn will make the diodes dirty and stuff it...MAF = AFM (Air flow meter). Backfires can cause the hot wire in the afm(Tiny wire in a triangle shape) to blow out.

as for the

(P.S - were you at Bathurst in 2006 with a couple of mates wearing sombreros and maroon coloured Ts with your '24 beers in a carton...' line printed on the front?)

nope sorry bud that was not me :P

[Nackerz]

No worries man hope it helps ya out