2000 4.3 Slight Miss on Highway

[Siegel1719]

2000 Jimmy with 4.3
165K Miles
New Aftermarket fuel pump few months ago
New Cap and Rotor 2 years ago
New Wires and AC Delco Plat Plugs 6 Months ago

On freeway has a very slight miss at about 60mph(1900-2000 RPM)
No miss at 70 (2200RPM)
Also no miss any lower or on city streets that ive ever noticed
Cheak engine light came on a few times(Think 3) over the past 6 months stating random misfire and always on the freeway.

Any clues where to start?

Thanks
Jeremy

 

[moneypit]

cap and rotor 4.3s are real picky with ignition, get a good one Ive had the best luck with conrad brand with the brass contact points

 

[dave89iroc]

cap and rotor 4.3s are real picky with ignition, get a good one Ive had the best luck with conrad brand with the brass contact points

agreed, lower quality caps fail regularly