Symptoms
Hard hot starts, intermittent stalling that clears once the engine cools, misfires or erratic running on a fuel-injected V8.
The fix, step by step
- The Thick Film Ignition module bolts to the side of the distributor, close to the thermostat housing, where Bronco Graveyard says engine heat eventually kills it.
- Disconnect the battery, unplug the module, remove its two screws (a long T20 driver or Ford's module tool helps), and slide it off its terminals.
- Coat the mounting face of the new module with dielectric grease, which acts as a heat sink, and fit it.
- Bronco Graveyard recommends genuine Motorcraft modules and notes that many owners carry a spare on the trail.
Tools & part numbers
- T20 Torx or Ford ignition-module tool
- offset distributor clamp wrench (if the distributor has to come out)
- dielectric grease.
Where to buy the parts
1985–91 Ford distributor ignition-control TFI module (Motorcraft)Bronco Graveyard ↗Amazon ↗
Ford Motorcraft V8 spark-plug wire setBronco Graveyard ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Ford Full-size Bronco parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.