Microtech on 4.0l twin turbo. 15000 rpm???

Hi there, just after a little help with my Aussie 4.0l. I have a microtech lt10s hooked up and was runing fine but now it misses under high load/ high revs and the log indicates maximum rpm achieved was 15980....! Obviously not the true rpm reading. I'm guessing the miss is my rev cut kicking in when the ecu thinks its doing 15980 rpm, the dizzy is relatively new and the wiring is only a couple months old. I'm going to run 2 new wires to and from the tfi module and double insulate them. Has anyone had any problems like this? electrical interferance maybe? A short would be the obvious place to start as the sensor runs a variable voltage to give it its crank angle and this is the only way the ecu could reference rpm. Or does the ecu read rpm off of ignition pulse and thus if ignition dropped out or coil shorted, it would read a high rpm...?

Any ideas?

Is there anyway the ecu is getting a doubled rpm count? Maybe rpm sensor is reading two impulses each rev.
I'm guessing, Ok. If ecu was for senor on cam it would get half as many impluses then ecu doubles. Whereas a sensor on the crank would read actual but the ecu is for a cam rev sensor it doubles count.

Very good thought but the rpm reads true to the tacho at all times except when it misses, today i drove it and it ran fine, boosted to 13psi and reved to 5350rpm, rev cut set at 5000 at the moment so just a little over run after the cut. I'm thinking of just building a whole new harness.... I originally designed the current one to work with the stock ecu. i.e the stock ecu is still plugged in and still controls the starter circuit and powers the o2 sensor and various other things with the microtech only having tps, water temp, air temp, internal map, fuel pump realay, the tfi pip and spout signals, injector outputs and o2 sensor signal wire hooked up. Maybe i need to order a whole new harness and start from scratch here? wire in the powers and earths for all the components the stock ecu is still conrolling and run the microtech as stand alone? Really close to being a genuine 300 rwkw monster but just need to iron out these little issues

Ok so i found sumthing interesting when i poked about a bit. Checked timing and it was 10 degrees too advanced all around, static timing in the ecu was set to 00 deg but the dizzy was at 10, adjusted that all back to spec. Should be able to bost her even more now, was pinging at 14psi before. I have devised that the problem only shows itself when hot, hence the drive thismorning didnt have any dramas as ambient temp was only about 3 degrees c and the coolant temp didnt get to its max of 84c, only reaching 74c before i got to work. I have replaced the ignition module as i had one in my tool box anyhow. The tfi modules often give troubles when hot though normally the engine just stops all together but the symptoms may vary with an other than stock ecu? Will let you know the results tomorrow...
Cheers

Sorry its taken so long, the ignition module didn't fix it but i have sorted it out. Decided seeing as my wiring had checked out and the ignition module did not fix it that it was either dizzy or ecu. I had a dizzy, brand new in box (I have alot of ford spares lol, been messing with this vehicle for 4 years) so thought id replace it. When i pulled the old dizzy (only 12 months old i might add) the roll pin had shattered but still remained in there and holding the gear, but allowing it to turn about 2-3mm back and forth. Cheers for all the help people. The big girl gets a wade 977b-14 camshaft and a custom short runer intake plenum this week and then its off for the final tune. Should snag in excess of 400rwhp providing the dizzy can keep the spark up