My V10 1999 F350 just suddenly started surging while at idle even worse when put in drive. Every thing is new coil packs, plugs, fuel filter, so what happened at 108K miles. If anyone else has this problem check the small connector hose under the throttle body, mine was collapsing. Replaced it a 3 inch hose from ford at 32.00 but it fixed the problem, also replaced the pcv hose at 25.00 from ford. Just a heads up for you to check if your older truck starts surging.