Q: 1999 Mitsubishi Eclipse running rich and stalling at idle

asked by on

I have a 1999 Mitsubishi Eclipse. It's running rich and stalls occasionally at idle. I've done a fuel pressure test and it looked fine, which I believe can rule out a leak in the injector. There is no MAF sensor and the throttle position sensor is reading 13% at idle. What is my next step?

First of all, you’ve got to realize that, although those technically don’t have a MAF mass air flow sensor, those use what is called a Karman vortex sensor. Those sensors are notorious for going bad on Mitsubishis.

They do the same thing--they measure how much air is going into the engine to tell the computer how much fuel is going to put into a fuel injector. You will want a certified technician, such as one from YourMechanic, to come and hook up a high-level scan tool and analyze the Karman vortex sensor.

That can easily be what the problem is. If it is not that, running rich either means that you are getting way too much fuel, or you are not getting enough air. So, you’d want to check and see if you have any air restriction on the intake.

Something as pesky as an air clogged air filter can do that. You can also have a problem with the fuel filter. You might check it, to see if the fuel filter is clogged or anything like that. But, your throttle position sensor is reading 13% at idle. That is actually a little bit high. If it’s saying that it’s a little more open than it is, then the computer will send more fuel to the car and that will make it run rich. That a lot of times can cause that problem too. That’s a relatively common thing that happens to those cars. I recommend getting the car checked and having a qualified technician diagnose your stalling issue. That way, you can be more certain about what repair is 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. 1999 Mitsubishi Eclipse running rich and stalling at idle

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: 2003 Mitsubishi Montero Limited Stalls At Stops After Engine Is Warm

What you are describing sounds like a dirty or failing idle air control valve. The idle air control valve monitors the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and...

Q: air conditioner not blowing well

This vehicle is equipped with a cabin air filter that filters the air coming into passenger compartment. The filter blocks debris, and in time restricts the air flow. It requires replacement at least once a year. Another possibly could be...

Q: I think it's the radiator

It would not be advisable to drive the vehicle or further engine damage may occur. If you drive the vehicle and overheat the engine even once you could cause the head gaskets to leak or seize the motor. The cost...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
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...