engine miss @5000rpm on prem setting

[hammer]

bought 86 svo couple of weeks ago. Engine was rebuilt b4 I bought car and had 250 miles on it , took it easy next 700 miles. on regular fuel setting car gets 10 lbs boost and runs fine. on prem. fuel setting on WOT car misses badly at 5000 rpms when i back off of wot it starts to accel ok again. THE CAR MAKES 15 LBS BOOST ON PREM SETTING. Any suggestions, I have looked at plugs and they are gapped at .034 wires look ok but haven't looked at them in the dark. all vac hoses look ok can't hear any serious vac leak. Also car has ngk plugs i use to run split fires in my big cam turbo coupe with 20 lbs of boost and never had problems like this. What plugs do my fellow svo drivers run? I need HELP! PS engine was rebuilt to stock specifications and I only run premium in it.

BIG TURBO

[SVOeric]

does the engine still miss, even if you roll on the power, instead of stomping it, and holding the pedal down?

[svono50]

You might want to try and regap the plugs down to 0.028-0.030" and try it above 5000rpm again. I have seen this trick help misfires at high boost/rpm. The problem can be caused by dirty plugs, old wires, corroded cap/rotor or a host of other things including bad/low octane gas. When you get 15psi + 5000rpm the load on your ignition system goes up drastically, so your components must me in top shape.

[High Roller]

Paul Becker wrote an article entitled "silent killer" in the August 2001 issue of the SVO Enthusiast about the faulty ignition switches in our cars. My 84 never did run quite right until I replaced the switch. Replacing the switch may have no effect at all on your car, but considering that it is cheap and easy, what have you got to lose?