Subject: 1995 Mirage knocks 5-10 min on coldstart
Question: 1995 Mitsubishi Mirage 1.5 L
I bought the car in Aug 2002 for a supposedly "cheap" price verified via Edmunds.com. It had 95k (most of which were highway miles for her weekend commute to & from the univ which is about 4 hours away) on it and was very well kept by the previous owner for his daughter.
No issues with the car until winter came and it got cold in Dallas, TX. Somewhere in October or November it started giving me this problem.
The car would start initially and I would be able to drive to the shopping complex 2 minutes away (barely 200 metres) go to get the chinese meal and get back.
Car wont start. It would keep making that "uhh..uhhh..uhh.." noise. After pursuing it for 15 mins and leaving it for 20 mins to my luck it started again but with an exception. It was unstable and would knock and even die if i gave it too much gas.
This has continued till now March 2003 and is less frequent now due to oncoming spring.
The USUAL thing that would happen is, if I accelerated it (not floored) slowly it would get better once it reached higher gear & speed (its an automatic). Basically if 2-3 mins after starting I reach a traffic light and stop and then try to move, I HAD better do it REALLY REALLY slow. If at all I TRY TO GET MORE ACCELERATION INITIALLY and give too much gas, it would knock and die.
BUT - after 5-10 mins of driving (at a higher speed, when i reach the highway or bigger road) it goes away and once it starts to feed on a higher speed, it usually is not a problem. But at times even after higher speeds I have to make sure MY INITIAL ACCELERATION from ZERO is SLOW... and now I can rarely think of accelerating fast like I did when I bought the car. (It also bothers the people behind me at the traffic light).
PS: I am not sure how you define knocking, but I believe its stutters/sputters and makes knocking dying sounds and dies.
I do have OIL CHANGE / SERVICING due soon, but fact is this has been consistent even after the last change that I had.
What seems to be the problem ? A friend who I spoke to on the phone told me its possibly a fuel filter, fuel pump. When I called Bridgestone they told me they would charge me a 100$ just to check whats wrong.
I bought this car cheap and I cant blow away money on "no service estimate". I need some guidance before I approach a smaller mechanic or local guy.
Answer: Crash,
Your description was very good. Rarely do I get one this thorough. It will really help me diagnose this problem. I'll give you theory as to what's wrong, then I'll tell you why.

First, most cars hate cold weather. Just about every car is not designed for sub-freezing weather. Dallas rarely gets below freezing, but it gets cold weather nonetheless. For your starting issues, you should have your battery and starter checked. Your battery becomes weaker as the ambient temperature decreases. You can get your starter and battery checked for free at most major auto parts stores (AutoZone, PepBoys, etc..).

Your poor acceleration can be contributed to a few things. They are almost too numerous to mention, so I'll just list things to have serviced.

-Replace your spark plugs and plug wires (if you've never replaced them)
-Replace the fuel filter (cheap, easy, quick, and should be done every 10k-12k miles)
-Replace the air filter (should be done every year)
-Check and/or replace your distributor (should be repla
ed every 24k-30k miles)
-Replace your PCV valve (very cheap, very easy, and should be done every year)
-Change your transmission fluid (should be done every 30k-45k miles)
-Check your alternator (they usually have a life of 7-10 years)
-Replace your belts (timing, A/C, water, power steering)
-Check your fuel pump and fuel lines (the pumps usually lasts 5-10 years)
-Check the engine coolent (system should be flushed every two years)
-If you can afford it, get a synthetic oil change (synth. oil can last 10k miles between changes)

This is a big list, but most smaller mechanic garages can handle it. In some cases, you may be able to buy the new parts yourself, and take them to a mechanic for installation. That can save lots of money.

If you get all these repairs done and you still have accelereation problems, have your transmission checked by a transmission specialty shop. Most small garages do not have the tools or knowledge to work on transmissions. It almost sounds like your car is alway stuck in a high gear, or your torque converter is malfunctioning. This will always cause a slow start, then return to nomimal driving at high speeds.

There's also a chance your have one or many faulty sensors. The only way to check this is to have your car's computer scanned with a code reader. If you have an AutoZone in your area, they can scan your computer for trouble codes for free. I would highly recommend doing this. They can give you the code readings and you can usually buy the replacement part right from them.

My best guess is that this may be a minor problem and can be fixed relatively cheaply. Even if the previous owner kept the car looking good, you can never know how they treated the engine. If this car has always been in Texas, then it has seen some very extreme weather for the past 8 years. Floods, heat, rain, dust, snow, freezing temperatures will really play havoc on an engine.

Take this list of items to a decent mechanic in your area (ask your friends and co-workers for recommendations) and ask him for an estimate for servicing of these items. Honestly, all of the above in my list can come out to cost several hundred dollars, but your car will come back to life, and be good as new.
Good luck!