'93 5.0 A/T 4x4...when I'm at a light in Drive, foot on the brake, I detect a slight engine rough running. NOT enough to even make the tach flutter, but I know they're unreliable as far as this goes. Any ideas on where to start looking? Engine is all-original 79K ...pretty well maintained. TIA!

 

Spark plugs, wires, cap and rotor age?

If you replaced the above, were the wires routed properly to prevent crossfire?

 

Yes, plugs, wires & rotor were all done about 1.5 years ago....I *think* I may have actually found the culprit...Over the HVAC plenum (pass side of engine) there is a broken 'T' fitting and the hose is just dangling...it's a tiny hose, but it's a vacuum leak all the same.....I know these fittings have the durability of a soap bubble after 20 + years so I'll get to replacing them. Any good source for those?

 

do them one at a time, less headache, bronco forum tells you what sizes and length
Silicone Boost/Vacuum Hose
Replace Plastic Vacuum Hoses with Rubber - Ford Bronco Forum