Lot HOC1141: 1987 Ford Mustang GT

The 1987 Mustang GT’s 5.0L High Output engine has several well-known issues that owners frequently encounter:

Top 5 Most Common Problems:

1. TFI Module Failure - The Thick Film Ignition module is notorious for heat-related failures, causing stalling, rough running, and complete ignition failure. This is the #1 issue with these cars.

2. Idle Surge/Rough Idle - Very common problem caused by:

   • Dirty or failing Idle Air Control (IAC) valve
   • Vacuum leaks in the aging vacuum lines
   • Improper TPS (Throttle Position Sensor) adjustment

3. Vacuum Leaks - The 1987 models have extensive vacuum systems that develop leaks over time, causing rough idle, stalling, and poor fuel economy.

4. Timing Chain Issues - The factory timing chain and gears wear out, leading to timing noise and potential engine damage if not addressed.

5. Fuel System Problems - The 1987 models use early fuel injection that can have:

   • Clogged fuel injectors
   • Failing fuel pressure regulator
   • Dirty mass air flow sensor

Good News for This Specific Car: With only 21,817 miles and being “Original & Highly Original,” many of these issues may not have surfaced yet. The low mileage suggests the car hasn’t had the typical heat cycling that causes TFI module failures.

Prevention Tips:

• Replace the TFI module proactively (they’re inexpensive)
• Check all vacuum lines for cracks
• Clean the IAC valve and throttle body
• Consider replacing the timing chain assembly

Would you like me to help you find similar low-mileage Fox-body Mustangs, or do you have questions about inspecting this specific car?