VS Senator Crazy Tacho and Grumpy Idle

[Brendo169]

Hi there

Ive got a few issues with the senator atm
It seems to be really unhappy at idle and runs like a dog until it warms up. For example ill start it up and let it warm for a few minutes. Then when i start driving it is really unresponsive. Ill put my foot down a little more and nothing will happen for a few seconds and then it will kick in...then die a bit... really jerky
Once warm the problem is gone
Also when these symptoms are occuring the tacho jumps around like crazy

There is no power loss
No problems starting

Replaced ignition module, coil and dizzy last year with genuine parts
I did new leads last week but that didnt fix the problem

Car is running a 355 stroker. Plugs are less than 5000kms old

I might do the plugs this arvo and see how that goes

But im struggling to place the cause of the jumping tacho
i might check all the earths today aswell

[Brendo169]

what does everyone think
i pulled the plugs and they look fine...so im going to leave them...all earths are good
im thinking its one of the follwing
coil
dizzy
ignition module
my problem is that all three of these are less than a year old

anyone got another ideas?

[VrWagz1]

Sounds like could be the coil or dizzy cap. What did u do with ur old parts? and were they rooted or just swapped out for xxx reason. I would try them before spending your hard earned cash on a ignition module.
Start it cold at night, give it a few revs and see if u can see any arcing in the engine bay around the high tension stuff. Unfortunatly as it seems you may have found out, these engines are hard to diagnose with any accuracy on faults to do with spark. Its more a caculated guess, pretty much following down the line from the ignition module to the spark plugs till you jag it.
Just have a puruze over ur primary wiring on the coiul too, check its not rubbing or somthing.

[BlackVXGTS]

Also try replacing the ignition lead from your coil -> distributor.

[Brendo169]

alright chucked in a coil i had lying around and the problem was still there. so im leaning towards the module. would a faulty module be worse when cold or warm
cus the car is undriveable cold. have to feather the throttle to keep it running and is almost normal when warmed up

i thought ignition tended to worsen as the car heats up

[VrWagz1]

With electrical issues, things generlly get worse as they warm. Mainly cause resistance increases with temperature. But if there is like a crack or somthing in a solder joint somwhere, the heat may help things expand and close the crack making it better.... But, if you have access to the module or a mates to swap out and test, i would give it a go.

[Unfolded-V8]

I had a rough idle,bouncy tacho.. felt like the engine was coughing and spluttering etc , Replaced the ignition module - Problem was solved

[Brendo169]

New ignition module fixed the problem. Cheers fellas