Ford Repair: increased idle speed, spark plug wires, ford f350

Question
I changed the rotor and cap and spark plug wires on a 92 ford f350 with a 460.I
did not do anything with the idle speed, but it increased to 1200 rpms.  Could it
be a bad idle air control solenoid?

Answer
Keith,

Yes it is possible, but I would double check your wires. If you accidently moved each one over one spot it would advance the timing causing idle increase.  On a Ford #1 cylinder is passenger side front, follow it too the cap and make sure it is on #1.  Also, you might have a bad TPS sensor wire that got bumped. Yet another possibility, did you remove any vacuum lines that were in the way and forget to hook them back up. I had a student once who left the brake booster line loose on a Camaro. Seemed obvious to me, but he had missed it.

Food for thought.