4.3 vortex center port injection
fuel pump is fine


my truck has to crank a few times before starting some times, sometimes it starts right up.

it surges on the high way between 50 mph and 60 mph
but few time it may just surge

i am due for a tune up
but im not convince that's my problem

i also just did a tire rotation, and now my truck shakes really bad on the high way.

i use to have a problem where when i go 40- 45 mph my truck would shack, it was my universal of the drive shaft.

could another be bad, and what one?

please any suggestions will be trouble shot.

i am a mechanic in my free time,and love my chilton's

i am trying to narrow my possibility's, thanks
i have brand new sierradial delta a/t
235 70 15

almost nre, under 2,000 miles
alomst under 2,000