Thought I would start a different post on 1 of the constant issues with my sc, the old random misfire problem. Iv read a lot of posts most with no out come. So will keep this up dated until its cured and it mite help someone else.
So far all the usual suspects checked and replaced.
1. Engine smoke tested vacuum leak fixed
2. New pcv valve and rubber hose mod
3. New plugs and genuine coils
4. Fuel system checked, fitted with lpg same on both fuels.
5. Sniff test done no hg issues
6. Compression test done all in range
7. Maf sensor replace genuine denso

The misfire counts goes away once warmed up returns to almost zero once hot and running I can monitor live values when doing with the ID tool.

When I say random I do mean random when looking at the misfire count you would say swop out that plug or coil well this xcreen shot is after doing all the plugs again and fitting new coils.

Are the knock sensors known to fail when cold ?? As its proberly the last thing left but I get no codes or check engine light.

The random nature of the misfires
Cylinder 2 hit count goes high then the counter resets and cylinder 2 reads zero for misfires. The previous cylinder no longer hits the high number either.
Totally random

More investigation and playing with the ID tool my egr is reading -100% looks like it's jammed open but shows no codes.

Unless some one can tell me different.....I am unable to find an egr on this engine

After a brain storm im going to replace the sc snout bearings as there fecked I'm thinking there causing the knock sensors to misread the vibration from the faulty bearing as cylinders misfire........Will check again after sorting the sc snout.

I'm following this. I have a very similar thing going on with misfires and my supercharger is rumbling a bit too. I think mine is just the coupler but if your bearing/coupler fix works I'll send you my charger to rebuild👍

Haha iv had the full repair kit sat here almost since I got the car I think it was the 1st thing I bought for it but the vac leak and other minor issues needed sorting 1st

Am still waiting todo this as iv been very busy with work and sadly had x3 deaths in the family to deal with iv got some time off comming up so will pull the supercharger off strip it down and rebuild it.
I did think for a minute to have powerhouse do it for me just because iv been so busy 2 things put me off this 1 it's a bloody long drive from me to them 2 they wanted it for a week oh 3 think they quoted me over a grand.

Just waiting for decent weather........

Just to close this 1 iv had the bearings and coupler replaced in the sc snout today and can report no more random misfires




It does seem these were causing the misfire count on the gap tool after all.

Job done