Posdible Holden 5 Litre Ignition Module Failure?

[Dylan]

Today I took my car out for a drive. VR Commodore 5 litre manual running 12P.
It was 41 degree today. I recently had a big win with my tune it's been driving really good even in 30 deg weather.

After 30 seconds of engine running it starts cutting out dead, I backed straight out of the shed so I'm on the road at this stage. Not even missing just straight dead then pick up again a second later all ok.

So I turned around at the corner straight home. My drive way is a steep hill so I couldn't get up it because it died on the way back and I rolled half way up. It wouldn't fire again so I plugged in a spare module still no better.
After a while of cranking it finally starts but runs shit with full throttle only maintaining a very week idle of 1500rpm.

My plugs are now very black and were wet when I pulled a couple out. Up un till now they've been perfect even after long idles (thanks to closed throttle VE God bless it)

For spark delivery I'm running an MSD digital 6A so I went back to standard with module firing the coil still no better.

Any thoughts if a crook module could deliver this problem? The cutting out was random I could not notice any consistent rev range or speed although it was a short drive unfortunately I wasn't logging.

[vlt304]

check the injectors are pulsing not just holding open as the driver in the old 808 sometimes fail and hold the injectors open/flood the engine

[Dylan]

Good idea I've actually heard that now I think about it. Thanks

[delcowizzid]

check fuel reg vacuam line for fuel.also connect your laptop and look at coolant temp in the data stream when it starts having a hissy fit does coolant jump around

[Dylan]

check fuel reg vacuam line for fuel.also connect your laptop and look at coolant temp in the data stream when it starts having a hissy fit does coolant jump around

Thanks mate, gotta hook msd back up and fit new plugs Friday and get some logs done. It's been perfect since last round of tuning. Hopefully nothing expensive I was hoping to get a wide band soon, although the plugs look pretty good. Is that a good way to tell how well the fuelling is?

[Holden202T]

I would suggest if it was ignition it would probably not work again after failing!

my first thought was coolant wiring or sensor too, if it goes fully cold it will almost flood the engine, but best thing you can do is get a full message log when its doing it!

[Dylan]

When I checked the plugs they were wet so possible

[Holden202T]

a while back i did a tune for a guy, 286 cam 304, all good, 3 months later he rings me up telling me its mostly fine then just randomly it will just shruggle and pumps black shit out the back, then just comes good.

plugged the laptop in, the coolant went from 80 deg to -40 then back to 80!!! turns out the wires for the CTS under the TB were basically turned 180 out of the plug and the plastic was brittle and cracked off, so they were shorting together sometimes!

[VX L67 Getrag]

I know there used to be an issue with the modules when hot they failed & remember someone saying its either a faulty diode or dry solder or something in the module & easily rectified, but obviously you'd loose spark if that was the case!

[immortality]

Also been a few instances of late with the sensor in the distributor playing up but I to would have looked at the ignition module first.