Ignition Problems

[Chalky01]

Hey people. Well lets get started lol. I was driving my car around the other night and it started this loud bum bum bum noise. I found out it was that cylinders 1 and 4 werent firing. I took off the individual coil for 1 and 4 and checked the primary and secondary resistance (which was okay). I also swapped the coil with another one. It was that same right side position of the DFI (DFL DLF DDL, whatever its called) module that wasnt working. I got power from the battery to the DFI module. I put it all together after looking and testing, and then it worked!! for about 5 minutes in which it proceeded to turn off the 2 cylinders, so back up the driveway i go and surely enough it started working again. Im completely dumbfounded, and ive booked it into the holden dealership, but i was just wondering if anyone on here had any ideas on whats happening?

Thanks!!! =D =D =D

[Brett_jjj]

I'd check for error codes first,see if anything shows up.Checking error codes VR/VS (Revised)
It could be the DFI (Direct Fire Ignition module) under the coils (the thing the coils sit on and plug into),or the CAS(Crank Angle Sensor) which is behind the harmonic balancer.I've seen both of these things cause misfiring when the coils are showing to be ok.

[Chalky01]

Hey! sorry for the late reply. Lol turns out it WAS the DFI. Apparently if the CAS is playing up, all of the cylinders wont fire because its only got the one signal . Got it replaced today about midday and been driving around like theres no tomorrow lol. But thanks anyways mate!