Engine breaking up under boost


87 GN hardtop
Aug 17, 2007
I was running a stock turbo at 21-24lbs with only very little knock. I just put on a TA-51 with a powerplate and at 20#s the engine seems to be randomly cutting out (like a missfire) above 15#s of boost, the knock is still 0-4 max.

Otherwise the car runs fine. It's a new TT chip (no alky). I ohmed the stock plug wires, all were 9k-12k (manual says under 30k is ok).

The coils are 10k-15kohms.

Any thoughts?
Might start by checking all grounds especially those by rear of passenger head. I'd also look for a loose plug wire boot or loosened spark plug. Do you have a spare ign module/ coil to try out?
I'm running Delco R43TS plugs at .035" gap. I don't have an extra coil pack or module for testing either.
I had the same problem with mine and it turned out to be a bad coil..Drove me nuts.............Good luck
try closing the gap on the plugs to .032 i like ngk ur5's. since you like ac delco get the AC CR42TS for yours.
i run r42ts with .028 gap . with bigger gap you could be blowing out the spark.can't ever go wrong with $12 worth of new plugs especially if you had run race gas on them and they could have lead deposits on them too. i know you say your running alky now but what about before?