Limiter Problem?

[UK Racer]

Help please. I've just come back from a first weekend of racing using our new Digital 7 system. The car runs fine on the street but when in race mode first gear is great but as soon as I hit top (it's a Glide) the revs seem to limit at around 4400 rpm. I thought it might be something to do with the launch control (as that was set at 4500) so moved that sky high but got the same result - charges hard then, as soon as I shift it won't rev. Any suggestions? I've got just three weeks to the next meeting and no testing opportunities!
Running through the various connections I noticed that the third retard wire (tan) is not earthed. We do not currently use this wire but the instructions do not request it to be earthed. Should it be?

[MSDTECH8]

UK Racer


Can you please give the model # of the Digital 7 Ignition you are currently using, and a brief description of your application?

MSDTech8

[UK Racer]

Hi there,
The model is a 7530 (V19 as I remember).
The application is a 477 Ford, CJ heads, tunnel ram, 2x Domi, MSD crank trigger, M*llory dissy, MSD leads, pump fuel + booster, 2 Foggers (although 'rev limiting' occurs without N2O. I have checked output from data logger and RPM drops exactly on 1-2 shift and just won't pick up again. Launch curve is triggered by trans brake, run by rev drop. If you need any more please ask.
Thanks