97Civic SOHC loses spark when cranking and under load.
 

I've got a 97 Civic LX SOHC. The car is new to me and ran fine when I bought it. The problem started when the car was being driven. The distributor and all related parts were replaced right before i bought it. The car reluctantly starts and when put under load begins to stutter and miss. I've hooked up an OEM ignition spark test light to each of the cylinders individually. No. 1 cylinder seems to be mostly unaffected until under heavy load(around 2800 rpm with tranny in D and foot on the brake), the other cylinders all seem to have a weak or totally lose spark intermittently when in drive until under heavy load when the engine will start to miss badly and will die unless you get out of the throttle quickly at which time the engine will run rough for a few seconds then strong spark will return and car will idle smoothly. I'm thinking it has to be a problem with the ICM or the signal to it but don't know how to test it without just installing a new one and I don't want to spend the money on just a guess.