Q: Cold engine misfire and hesitation - 1997 Dodge Dakota

asked by on

My issue is when I first start the truck I have to let it sit for a minute or so before I take off. If I try to take off without performing this warmup ritual it will misfire and lose power until it warms up. Once warm it smooths out and seems to run perfect. It doesn't seem to idle up like most cars do on cold starts. It goes strait to normal temp idle speed. Somewhere around 725-750 rpms. It will idle with a misfire for a minute or so and then smooth out and won't return until the next cold start. Theres not a check engine light. Ive changed the plugs, wires, cap, rotor, tps, iac, and pcv valve with no change. I had a parts store hook a scanner up to it while running and at normal op temp and the upstream o2 sensor was bouncing from .14-.900 volts. The intake air temp was 165. It was 45 outside. Its taking in air from the fender well not from the hot engine compartment. i know it will read hotter than 45 b/c it's in the manifold but 165 doesn't seem right. Is that normal?

My car has 150000 miles.
My car has an automatic transmission.

Hi. I believe the ambient air temperature sensor, which measures the intake air temperature for engine management, has failed. It is reporting a far higher temperature than the engine is getting, as you have noted. Engine management is creating a leaner mixture for the engine than it really needs during cold start, so it misfires and has low power.

Replacing this sensor should improve cold start behavior. I would recommend having a certified mechanic, such as one from YourMechanic, come to your location to determine why the car is hesitating and replace the air temperature sensor if needed.

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. Cold engine misfire and hesitation - 1997 Dodge Dakota

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: 2015 Equinox hesitates at traffic light

She's probably telling the truth. Some dealers can be lazy. They don't want to do anything for free, under warranty. There's a lot more they could have looked at other than just codes. Anybody should road test the car with...

Q: White smoke coming from engine and into the car from vents upon starting the car and then clears.

Hi there, Check the fuel system on your engine to see if the fuel pressure regulator is working properly. It seems that either the fuel pressure regulator is putting a higher pressure on the fuel injectors or the cylinders 2...

Q: Truck cuts off when stopping

Hello. Stalling at stops can be caused by many things. A few common causes are: faulty idle air control valve vacuum leak fuel or engine management issue The most common of these is a failed idle air...

Related articles

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...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
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...