1991 Dodge Stealth Has Rough Idle

Diagnosing the Causes of Rough Idle in Your 1991 Dodge Stealth and How to Restore Smooth Performance

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Reviewed by
Bo Fader
Written by RepairPal Car Genius
Updated January 14, 2025
0%
21% chance it's the
Spark Plugs
0%
15% chance it's the
Ignition Coil
0%
64% chance it's
Something else
The most common reasons a 1991 Dodge Stealth has rough idle are a vacuum leak, an issue with the spark plugs, or a problem with the ignition coil.
  • Spark Plugs: Worn or fouled spark plugs can lead to misfires, poor fuel economy, and difficulty starting the engine.
  • Ignition Coil: A faulty ignition coil can cause misfires, rough idling, and difficulty starting the engine due to inadequate spark delivery to the spark plugs.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a 1991 Dodge Stealth has rough idle?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

Here are a few common symptoms of worn-out brake pads:

  1. Low brake pad warning light is on: Not all vehicles are equipped with this system, but if yours is, this dashboard indicator light will likely be the first signal it’s time to replace your brake pads.
  2. Brakes start to squeal regularly: This is often one of the first signs of worn brake pads and is caused by a metallic piece built into brake pads for this exact purpose. This part contacts the brake rotor to make a squealing or whining noise when the pads are low.
  3. Brakes make loud grinding noise: If not addressed early enough, your brake pads may get so worn that the metal backing plate of the pad grinds against the metal rotor.
  4. Brake pads look thin: You may be able to visually check your brake pad thickness to determine if they need replacement.

Most often, a brake system inspection will just be a routine portion of manufacturer specified maintenance, and will be performed at mileage intervals. In those cases, there will likely be no symptoms. However, when a brake system makes a funny noise, causes vibration, is hard to use, will not slow the vehicle, prevents the vehicle from driving, makes the vehicle pull to one side, or leaks brake fluid, the vehicle will need a visit dedicated to the inspection of the brake system.

What are the steps to diagnose and fix a rough idle in a 1991 Dodge Stealth?

To effectively diagnose and fix a rough idle in your 1991 Dodge Stealth, start with a systematic approach that prioritizes simpler checks before moving on to more complex diagnostics. Begin by inspecting for vacuum leaks, as these can significantly impact engine performance. Next, examine the spark plugs; worn or dirty plugs can lead to misfires and rough idling. Cleaning the Idle Air Control Valve (IAC) is also crucial, as it regulates the engine's idle speed. Following this, ensure the throttle body is clean to maintain proper airflow. Don't overlook the Mass Airflow Sensor (MAF), which should be free of dirt and debris to function correctly. Testing the fuel pressure is essential, as low pressure can contribute to idle issues; replace the fuel filter if necessary. Additionally, check the EGR valve for carbon buildup, which can disrupt idle quality. Utilizing an OBD-II scanner to check for error codes can provide insights into specific problems. Finally, if all else fails, adjusting the idle speed may be required. By following this structured diagnostic approach, you can effectively identify and resolve the rough idle issue in your Dodge Stealth.

What are the common causes of a rough idle in a 1991 Dodge Stealth?

When diagnosing a rough idle in a 1991 Dodge Stealth, it's crucial to consider several common problems that could be at play. One of the primary culprits is vacuum leaks, which can significantly disrupt the air-fuel mixture, leading to an unstable idle. Additionally, dirty or faulty fuel injectors may hinder proper fuel delivery, exacerbating the rough idle issue. Worn-out or malfunctioning spark plugs can also cause misfiring, contributing to the roughness. Another potential problem is the Idle Air Control Valve (IAC), which regulates the engine's idle speed; if it’s faulty, it can lead to erratic idling. Furthermore, a malfunctioning oxygen sensor can throw off the air-fuel mixture, while a clogged air filter can restrict airflow, both of which can result in a rough idle. By systematically checking these components, DIY enthusiasts can effectively identify and resolve the underlying issues causing the rough idle in their Dodge Stealth.

How urgent is it to address the rough idle in my 1991 Dodge Stealth to prevent further damage or safety risks?

Addressing the rough idle in your 1991 Dodge Stealth is not just a matter of convenience; it is crucial for your vehicle's health and your safety on the road. A rough idle can indicate serious underlying issues such as engine misfires or problems within the fuel and ignition systems. If left unchecked, these symptoms can lead to decreased fuel efficiency, increased emissions, and even catastrophic engine damage, which can be costly to repair. Moreover, a rough idle can compromise your vehicle's performance, making it less reliable and potentially unsafe to drive. Therefore, it is essential to prioritize this issue and seek a professional diagnosis as soon as possible. By addressing the rough idle promptly, you not only enhance the longevity of your Dodge Stealth but also ensure a safer driving experience for yourself and others on the road.

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1991 Dodge Stealth Rough Idle Causes & Repairs | RepairPal