Manifold Absolute Pressure Sensor Guide for the 1985-1995 Buick Regal
A failing MAP sensor can cause a rough idle, poor fuel economy, and stalling; this guide explains how to choose the right replacement.
- A failing MAP sensor on your Regal will cause noticeable running issues like rough idle, poor power, and bad gas mileage.
- Common OBD-I trouble codes are Code 33 and Code 34, which point directly to a MAP sensor problem.
- Replacement is very easy and can be done at home in under 30 minutes with basic tools.
- Choose a reputable aftermarket brand like ACDelco, Delphi, or Standard Ignition for a reliable, long-lasting repair.
Symptoms of a Failing MAP Sensor
When the MAP sensor on your 1985-1995 Buick Regal starts to fail, it can cause a range of noticeable engine problems. Because the sensor provides incorrect information to the engine's computer, the air-fuel mixture and ignition timing can be thrown off. You might notice one or more of the following issues:
- Rough or Erratic Idle: The engine may shake, stumble, or struggle to maintain a steady RPM at a stop.
- Poor Fuel Economy: A bad sensor can trick the computer into injecting too much fuel, causing your gas mileage to drop.
- Lack of Power and Hesitation: During acceleration, your Regal might feel sluggish, hesitate, or stumble.
- Black Smoke from Exhaust: If the engine runs too rich (too much fuel), you may see black smoke coming from the tailpipe.
- Check Engine Light: For this era of GM vehicles, a failing MAP sensor will often trigger a Check Engine Light with specific OBD-I trouble codes, most commonly Code 33 (high voltage/low vacuum) or Code 34 (low voltage/high vacuum).
- Stalling: In some cases, the engine may stall unexpectedly, especially at idle or when coming to a stop. 🎬 Watch: A detailed breakdown of bad MAP sensor symptoms.
Other Problems Can Mimic a Bad MAP Sensor
It's important to note that issues like a vacuum leak, a faulty EGR valve, or a bad electrical connection can cause similar symptoms and may even trigger a MAP sensor code. Always check for cracked or disconnected vacuum hoses connected to the sensor before replacing it.
🎬 See how to diagnose a rough idle and Code 33.Choosing the Right Aftermarket MAP Sensor
For a vehicle like the 1985-1995 Buick Regal, you have several good options for aftermarket MAP sensors. The original parts were typically made by GM's ACDelco division or by companies like Delphi that were part of GM. Today, you can get parts that meet or exceed original quality without paying dealership prices.
Brand Quality Tiers
Not all aftermarket brands are created equal. Here’s a breakdown of the brands available to help you make an informed choice:
- Premium Aftermarket (OEM Equivalents): Brands like ACDelco and Delphi are excellent choices. ACDelco is the original GM parts brand, and Delphi was a long-time GM supplier. Choosing one of these ensures a part designed with the original specifications in mind. NGK (also known as NTK for sensors) is another top-tier brand known for high-quality electronics.
- Quality Aftermarket: Brands such as Standard Ignition (SMP), Walker Products, and Hella offer a great balance of quality and value. They are well-respected in the industry and produce reliable sensors that are a dependable alternative to the premium brands.
- Economy Brands: Brands like Facet, Global Parts, and True Tech fall into the budget-friendly category. While they offer a lower price point, quality can be more variable. They can be a suitable option for a budget repair, but may not have the same long-term durability as the premium or quality tiers.
Pro Tip: OEM vs. Aftermarket
For an electronic part like a MAP sensor on this generation of Regal, a premium aftermarket brand like Delphi or a quality brand like Standard Ignition is often just as good as the ACDelco part, sometimes even coming from the same factory. The key is to stick with a reputable brand to avoid performance issues from a poorly calibrated sensor.
Typical Replacement Costs
Replacing the MAP sensor on a 1985-1995 Buick Regal is a straightforward and affordable repair. The part itself is not expensive, and labor is minimal.
| Item | Estimated Cost |
|---|---|
| New Aftermarket MAP Sensor | $32 - $133 |
| Shop Labor | $40 - $60 |
| Total Estimated Cost | $72 - $193 |
Cost estimates are based on national averages and may vary by location and specific product choice.
Frequently Asked Questions
Where is the MAP sensor located on a 1985-1995 Buick Regal?
The MAP sensor is typically located on the engine's intake manifold, often near the throttle body or mounted to a bracket on the firewall/fender rail with a vacuum hose running to it. It is a small, black, rectangular plastic component with a three-wire electrical connector and a port for a vacuum line.
Is this a difficult part to replace myself?
No, this is a very DIY-friendly repair. Replacement typically involves disconnecting the negative battery terminal, unplugging the electrical connector, detaching the vacuum hose, and removing one or two small bolts or screws. The entire job can usually be done in under 30 minutes with basic hand tools.
🎬 Watch: This video shows how to replace a GM MAP sensor.Can I just clean my old MAP sensor?
While some sensors can be cleaned, the MAP sensor is a sealed electronic unit. The failure is usually internal to the electronics, not because it's dirty. Some guides suggest cleaning the port where it connects to the manifold, but if the sensor itself has failed, cleaning will not fix the problem and replacement is the only solution.
Are there any recalls or TSBs for the MAP sensor on my Regal?
Searches of the National Highway Traffic Safety Administration (NHTSA) database and for Technical Service Bulletins (TSBs) did not reveal any specific recalls or widespread service campaigns for the MAP sensor on the 1985-1995 Buick Regal. Failures are typically due to the age and heat cycles of the electronic component.
Helpful Videos
Technical Specifications
OEM Part Numbers: 16187556 12569240 213-796
3-pin electrical connector, single vacuum port, 1-Bar pressure range.
We Have This Part in Stock
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.
- Buick Regal: