1999 Honda Accord • 150,000 miles

Car cranks & runs well at lower speeds, but begins hesitating between 70-80 mph. New plugs & plug wires. Added fuel system cleaner to tank today.
Planning to drive from NE Oklahoma to SE Michigan in this car in next few days. Any help will be greatly appreciated!
June 2, 2013.

Hesitation only at high speed could be due to insufficient fuel delivery. Have the fule filter (intank) checked. Checking the fuel pressure and pumping volume is the correct way but you might not have the required tools and equipment so removing the filter would be the next best option.

Jun 3, 2013.
Hesitation now at slower speeds & at idle, but neither always. Seems to run better when cooler, then worsens when warmed up fully. If a plug or wire were bad it would Be constant, correct? I appreciate you taking your time to help me.

Jun 3, 2013.
Yes, bad spark plug wires or plugs would have the symptoms showing more regularly but I am not sure of the exact symptoms so I would not rule out the possibility of bad spar plugs and related somponents.
You might have a failing ignition coil.

Jun 3, 2013.