Chevy & GMC Vans

i have a 99 safari that has been throwing a p0300 misfire code and cam to crank fault code. i replaced the cam and crank sensor witch seemed to get rid of the cam to crank fault code but i cant seem to get rid of the misfire. i have replaced the plugs,wires,cap and rotor. and it still misfires when i accle but if i get on it it doesn't do it. also when it misfires as i am trying to maintain speed it distorts my speakers.some time the check engine light will go off and it will run fine . and as of recent it randomly wont start, i drove it 70miles from home and came out 3 hours later to go home and wouldn't start sat waiting for tow truck for about two hours then it fired up and drove for about two weeks then one morning was about 3miles from home and did the same thing only had it towed home cause it wouldn't start let it sit for the day and came home and fired right up. i have looked for bad wires cant seem to find anything . what could it be




i just did a compression check and had igniotion mod check all are good 160psi

[youtube]http://www.youtube.com/watch?v=ljiDxVCsWr4[/youtube]

Coils have also been a problem in these vehicles. As mentioned check for excessive wear in the upper distributor bushing. My Safari had the same random midfire problem. A new distributor cured it.

Thank you all for the help I replaced the coil and ignition mod just for good measure and so far so good

ok so i thought i fixed the random misfire but it still runs rough on the freeway and still cuts out the factory speakers when im driving so far the engine light has not come back on could it be a ground?