So still tackling issues with my 90 SC 5sp finally got the spark error to quit coming up in stored codes but noticing that under heavy load my boost gauge will go from 15lbs (10% pully) and quickly bounce higher then back when this happens there is a jolt in the engine its very fast of a jolt and let's say your in 5th gear doing 45 or 50 if you go wot it feels like a the engine shuts off for a mil-second and grabs again plugs and wires are good correct order just not understanding what's causing the problem I think the SC tensioner is nearly worn out so definitely will be replacing it and the belt but any one know of anything else to check I've replaced most if not all the sensors switches modules and things like that too many to even rember which ones I've done over the past 3 years also looking for a good engine harness for the dis moduel if anyone has one that's in good shape let me know