Mitsubishi Repair: Mitsubishi Colt 00 Engine trouble, torque converter clutch, throttle position sensor

Question
Hello, I've had my colt almost 2 years. The problem with it began over a year ago and is just getting worse. Every morning, especially the cold/wet ones, the car splutters when starting. It takes a while to get going and normally involves a lot of rev-ing. It is sluggish and just running poorly. Now we've changed the Rotor Arm, Distributor Cap, and checked the Compression but still it is getting worse. I find that when driving on the motor way and overtaking, it looses power...it remains at the same acceleration even though it should be speeding up. This issue is getting worse and now that winter is setting in, I'm fearing the morning!!

Answer
Hi Helena,

I had a Toyota that did the same thing. The car had overheated at one point and it had warped the valves. You've said the compression has been checked; I'm curious if only one cylinder was checked for compression or all four. If the valves are warped it won't allow for proper compression, therefore disallowing the proper power generation from the explosion inside the chamber.

My initial suggestion would be to have the compression checked on all four cylinders. As well, not sure how long it's been since you've had your fuel/air filters and PCV valve changed but that would probably be a good idea, too. If that isn't the problem, they're components that should be regularly changed anyway so you're not really wasting your money.

If you've an Auto Zone or other parts stores close by, you may want to see if they'll code your car for you to check the sensors and the ECU. Auto Zone, and I'm sure others, will do that for free.  

Here's a list of what my book says are the possible problems for that symptom:

Throttle Position Sensor
Coolant Sensor
MAP or MAF Sensor
Air Transport Sensor
Ignition Coil
Distributor (which you've replaced)
Spark Plug Wires
Fuel Filter (mentioned)
Air Filter (mentioned)
Vacuum Leak
Engine Mechanical (any number of things)
Torque Converter Clutch

Possible but not probable:

PCV System (mentioned)

Sorry I couldn't pinpoint the problem for you but as you can see it could be any number of things. As I've stated to others, my philosophy is always go with the less expensive solution first...especially the free stuff!

Good Luck!