Chrysler Imperial Distributor Cap: A Guide for 1971-1983 Models
Keep your classic Imperial's ignition system reliable with the right distributor cap.
- The distributor cap is a critical wear item; symptoms like misfiring, hard starting, or stalling often point to a bad cap.
- For this vehicle, new aftermarket parts are the standard. Standard Ignition is a reputable brand known for quality and reliability.
- Always replace the distributor rotor at the same time as the cap for a complete repair.
- Replacement is an easy DIY task; the most important step is to transfer spark plug wires one by one to maintain the correct firing order.
Symptoms of a Failing Distributor Cap
A distributor cap is a wear item, meaning it needs to be replaced periodically. When it starts to fail, it can cause noticeable engine problems. Look out for these common signs:
- Engine Misfires or Rough Idle: Cracks, corrosion, or carbon tracks inside the cap can cause the spark to go to the wrong place, leading to engine misfires, stumbling, and a rough or shaky feeling at idle.
- Hard Starting: If the cap is damaged or has moisture inside, it can weaken the spark, making the engine difficult to start, especially in cold or damp weather.
- Engine Stalling or Backfiring: A severely damaged cap can interrupt the flow of electricity so badly that the engine stalls unexpectedly or backfires.
- Visible Damage: The easiest way to check for a problem is to look at the cap itself. Remove it and inspect for cracks, carbon buildup (black dust), or corrosion on the metal terminals inside and out.
Choosing the Right Aftermarket Distributor Cap
For a classic vehicle like the 1971-1983 Chrysler Imperial, original Mopar parts are virtually nonexistent. The market relies entirely on new aftermarket parts. This isn't a bad thing, as reputable aftermarket brands produce quality components that meet or exceed original specifications.
Brand Focus: Standard Ignition
Standard Motor Products (SMP), sold under the Standard Ignition brand, is a long-established and trusted name for ignition components. Their parts are known for being reliable service replacements.
- Quality: Standard Ignition caps are typically made from high-quality polyester resins that resist cracking and carbon tracking. They often feature solid brass terminals, which provide better conductivity and corrosion resistance than aluminum.
- Fitment: As a primary aftermarket supplier, Standard parts are designed to fit and function just like the original. For your Imperial, this is the standard, reliable choice.
Pro Tip: Replace the Rotor at the Same Time
The distributor rotor is the spinning component inside the cap. It wears out at the same rate as the cap. For a complete and reliable tune-up, you should always replace the distributor rotor whenever you replace the cap. Many owners also replace spark plugs and wires at the same time for a full ignition system refresh.
Distributor Cap Replacement Cost
The cost for a new distributor cap is very reasonable. The main variable in total cost is whether you install it yourself or have a professional mechanic do the work.
| Part or Service | Estimated Cost |
|---|---|
| New Aftermarket Distributor Cap (Standard Ignition) | $22.30 |
| Shop Labor | $50 - $100 |
Common Ordering Mistake
The V8 engines used in Imperials during this period (like the 440 and 318/360) have different distributor designs. Always confirm that the distributor cap you are ordering is correct for your specific year and engine to ensure proper fitment.
Frequently Asked Questions
How often should I replace my Imperial's distributor cap?
For a classic car, it's best to inspect the distributor cap and rotor annually or during any major tune-up. A good rule of thumb is to replace them every 20,000 to 30,000 miles, or sooner if you notice any signs of wear or performance issues.
Can I just clean my old distributor cap?
While you can clean minor corrosion from the terminals as a temporary fix, it's not a long-term solution. If the cap is cracked or has significant carbon tracking (thin black lines inside), it must be replaced. Given the low cost of a new cap, replacement is always the better option for reliability.
What other parts should I inspect when replacing the cap?
When you have the cap off, it's a perfect time to inspect the distributor rotor, spark plug wires for cracks or brittleness, and the points/condenser or electronic pickup coil inside the distributor, depending on your ignition system.
Is replacing a distributor cap a good DIY job?
Yes, this is a very straightforward job for a DIY mechanic. The key is to transfer the spark plug wires from the old cap to the new cap one at a time to ensure the firing order remains correct. Misplacing the wires will cause the engine to run poorly or not at all.
Technical Specifications
Fitment varies by engine (e.g., 5.2L, 7.2L). Cap should have brass terminals for best performance. Designed for use with a conventional external ignition coil.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.