Mercury / MerCruiser Quicksilver TMAP Sensor Assembly 8M0087834

The Mercury Quicksilver 8M0087834 TMAP Sensor Assembly is a genuine OEM temperature and manifold absolute pressure (TMAP) sensor used on many MerCruiser MPI gasoline engines. It measures both intake manifold pressure and intake air temperature, sending real-time data to the engine control module (ECM) to optimize fuel injection and ignition timing.

Key Specifications

Part Number: 8M0087834
Component Type: TMAP sensor (MAP + intake air temperature sensor)
OEM Brand: Mercury Marine / Quicksilver
Typical MSRP: about $110$130 USD depending on supplier

Compatible Engines

Commonly used on MerCruiser MPI engines with ECM 555, including:

4.3L MPI V6
5.0L MPI V8
5.7L / 350 MAG MPI
377 MAG MPI
383 MAG Stroker
MX 6.2L MPI

These engines are typically found in Alpha and Bravo sterndrive boats as well as inboard installations.

Function

The TMAP sensor performs two key measurements inside the intake manifold:

Manifold Absolute Pressure (MAP)
- Determines engine load and air density
Intake Air Temperature (IAT)
- Helps adjust fuel mixture and ignition timing

The ECM uses this information to:

Optimize the air-fuel ratio
Improve engine performance and fuel efficiency
Maintain smooth idle and throttle response

Common Symptoms of a Failed TMAP Sensor

A faulty sensor can cause:

Rough idle
Poor acceleration
Increased fuel consumption
Engine warning codes
Hard starting or stalling

Replacing the sensor restores accurate engine management readings.

Fitment Tip:
Always verify compatibility using the engine serial number. Many MPI engines look identical but use different sensor calibrations depending on the ECM generation.

Shipping:

OEM parts ship same or next day for fast Canada wide shipping.

Technical Specifications: