Q: Stalling, misfiring, and erratic idle - 1995 Chevrolet K1500

asked by on

After warm up, erratic idle rough running, stalling. Replaced iac, and tps.

My car has 189000 miles.
My car has a manual transmission.

Stalling and rough idling are usually an indication that the motor is not able to adjust to varying loads. The Manifold Absolute Pressure (MAP) sensor senses engine load and generates a signal that is proportional to the amount of vacuum in the intake manifold. The engine computer then uses this information to adjust ignition timing and fuel enrichment. When the engine is working hard, intake vacuum drops as the throttle opens wide. The engine takes in more air, which requires more fuel to keep the air/fuel ratio in balance.

When the computer reads a heavy load signal from the MAP sensor, it adjusts the fuel mixture to slightly more rich than normal so the engine can produce more power. The computer will then retard (back off) ignition timing slightly to prevent detonation (spark knock) that can damage the engine and decrease performance. This may also be caused by other closely related components, such as a dirty or failing mass airflow sensor, a faulty throttle position sensor, or potentially a vacuum leak.

I would recommend having an expert mechanic, such as one from YourMechanic, come to your location to determine why the car is stalling and determine if you need to replace your MAP sensor.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Stalling, misfiring, and erratic idle - 1995 Chevrolet K1500

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Car completely died with all symptoms of bad altenator while it was raining next day starts right up what could that be?

Hello and thank you for writing in. With the multi symptoms that you are experiencing with your vehicle, there are a couple things that are wrong. The first thing is the ignition switch probably failing. All of your power devices...

Q: Pinging sound a

Hey there, thanks for writing in about your 2012 Cadillac Escalade. A pinging noise is typically used to refer to spark knock or a damaged engine running condition. Did the Check Engine Light return with the same codes after doing...

Q: Put my GMC into gear and when I give it gas it just wines and won't move.

Hi there. Check the clutch to see if it is slipping. When a clutch slips, the engine will continue to operate but the transmission will not drive under a load. If the clutch is new and the noise is still...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...