why am i getting spark in only a few plug wires

Have you checked the cam sensor in the distributor.

I replaced it today.

May i ask how and when this started,may help me diagnose the problem?

just noticed the wires had no spark except for maybe 3 or 4 yesterday when I had my wife try starting the truck as I went from wire to wire . I thought the rotor bud or cam sensor so I replaced them.

didn't replace the cap because it looked fine.

Ok,have you replaced the plug wire,s?

no,because when I hook them to the coil pack and turn the truck on they spark.

Good to know,,give me a few minute,s to check something,

Have you checked this,

also when it does start it has a sucking air sound where the ias is.

It is probably drawing air because of misfire.

my crankshaft position sensor?no

This will cause random misfire if bad.

Is engine light on,and i can only assume it is,have it scanned,it will show if it is bad.

I can I tell if it's bad when I pull it?

You can ohm it,if you have ohm meter,if not take it to local auto part,s store and may be they will check it.

I've gone to autozone to have it scanned and they say vthey can't

my engine light doesn't come on that I know of but will look.

But if truck can be drove to part,s store ,it can be scanned to check it without removing it.

This would be the only other thing that would cause your problem,that you haven,t checked.The only other thing would be is the head has problem,s,and to check this do a pressure check on the cylinder,s to see if you have damage in the motor causing this.