[Leftyarmstrong]

Hoping there's a savy technician out there who can give me some direction. My '96 F150 has been garaged for much of it's life so it only just turned 100,000 miles. I'm getting a ping and a miss but only on a long grade up a hill when the engine is under load. It's been tuned with plugs, wires, cap rotor and well maintained. The hill is at sea level so it's not an altidude problem and it runs well around town. I've taken it to 3 shops including the dealer who all charge me to tell me the computer shows no codes. Of course they don't really want to be bothered with a phantom problem like this that they can't easily diagnose and fix. I could just start replacing the usual suspects but that could get very expensive. Any suggestions? Thanks, Don

[mechanickeith]

Just scanning for codes is not enough. They need to monitor the 02sensors & check A/F mixtures while driving the vehicle. Also need to monitor egr & fuel pressures during road test. First thing I would check is fuel pressures. Fuel pump may be going bad & runnign a bit lean.