I did some searching on this problem because it's happening to me an apparently a few other people with no solutions. thge only thing mentioned that was similar in a couple of cases was what I did previous to the problem occuring, I went through the de-flood proceedure by pulling the EGI fuse. The temporary solution seems to be to shut the car off and restart but unfortunately on good rev in neutral seems to kill it again. I should also mention my headlight switch burnt out around the same time as well.
So if anyone has the solution please pipe up, there are quite a few of us that need to know.
This weekend I'll be doing some much needed light bulb socket maintenance so as not to burn out the replacement light switch as per Icemark's recommendation.
And I'll replace all the fuses while I'm at it and clean the contacts.
And since the battery will be disconnected during all this hopefully the gremlins will clear themselves.
I'll get back to you all if'n it works.

 

I take it there is no associated loss in trailing spark?

 

Check your grounding wires, something may be loose in the harness as well, or you could be shorting somewhere. Also, see if you can find WHY that fuse blew, and if it just pops if you put a new one in it.

Best of luck to you.

 

Check the harness around the trailing coil connection. That corner likes to build up a lot of crud (mixed with brake fluid leaked from the brake and clutch systems, leaves from the corner of the hood, etc.) and it may have found it's way into the harness. You'll want to clean the contacts of the 4 pin weather tight connector with contact cleaner, then apply dielectric grease and reassemble.

 

Will do guys thanks for the suggestions. I suspect some clutch fluid may have gotten in when I replaced the clutchline the other month. I might as well check the guage cluster ground while I'm replacing the light switch and pulling stuff apart.

Rotary Noob I think you misunderstood, I have not blown any fuses as of yet, the tach works but dies intermittently.
I wanna replace all the fuses because some of them may be the original fuses that came with the car.

So electrical system maintenance weekend it is!

 

so in the s4 t2 theres a 7.5 fuse near the middle of the fuse box it right under the on thats raised up. i blew mine the other night and heard that if you blow it again and again then you altenator is going bad and it surges... idk for sure but we will see good luck with your electronic adventure

 

was looking at some of my old posts, thought I'd follow this up with the solution was indeed Aaron's suggestion