VN Rough idle

[BasNZ]

Hi, have a VN Holden 3.8 v6,had a slight ticking noise that I put down to a sticking lifter, well the other day I went to start it and it just went clank clank, wouldn't turn over, so charged the battery, still the same, took out the starter and tested it, all ok, got back under and turned the ring gear by hand,(was easy moving) put it all back together and it started, straight away, but with a new problem, now the motor runs very rough on idle and motor seems to shake and is still there on revving, oil pressure seems to be good. Does anyone have any ideas what could have happened, given the facts I have just stated, motor ran perfect before, has done 180,000km

Thanks...

 

[HarryHoudini]

The "çlank clank" type noise can be the Harmonic Balancer,it won't start as the CAS can be affected,if it does start it can run rough.Dealerships used to change them at 150,000 but you can get 180-200,000 K's out of them.
Anyway there are other possibilties but i would start there first.

 

[hi_ryder]

if you took your leads off check the firing order is right. check to see your leads are seated properly on the coil packs and spark plugs. make sure you didnt knock off any vac lines (map sensor ect). make sure your leads are properly separated from each other, like not all jumbled up on top of each other. check to make sure your alternator is charging at the right voltage. it might be running off the battery only which this cars dont seem to like. theres a little brown wire on your positive battery terminal called the fuseable link, if that breaks the alternator wont charge the battery and cause the car to run rough after the voltage drops a little. just a couple of things to look at....

 

[BasNZ]

Thanks for your input, leads. plugs etc all new, removed plugs cleaned, all good, but a little carbon build up, did one at a time, so leads are all in their right position, as ran great before, will try moving one lead at a time while running,(as soon as the rain stops...) and see it it drops each time, don't think the battery was that flat as only started it a few min's before and no sign of not starting. but just went clonk clonk as if the starter was jammed.. Would the Harmonic Balancer cause this as it was not making any noise as they do, sorry don't know much about it, but will check for wires and vac lines, but was only under the car at the starter, and disconnected the battery to charge it in the car.