17th Aug 2011, 17:40
Replace the "ignition failure module"; I've seen this particular little part cause misfires a lot! It's a device that actually is designed to detect misfires and shut off fuel to the injector of that cylinder that is missing. When they go bad, they shut off fuel to random cylinders causing codes like p0300 random multiple misfire and various other misfire codes and conditions. The other thing is that these cars have carbon problems BAD due to the intake design. What happens is the carbon builds up upon the surface of the intake valves in the cylinder heads, and causes them to stick and not seat properly, causing your concern as well. I recommend replacing the ignition control module and doing an extensive engine de-carbon.
This is a procedure that is performed as follows; remove the upper and lower intakes, and remove all six injectors and spark plugs. Get a couple of cans of good intake cleaner (something with a high content of acetone), spray down into each cylinder as well as intake ports of the heads, clean out what you can, but let the solution sit in the intake valves for about 15 minutes or so to help break up the carbon build up, and spin the car over to "blow out" the rest. Do this about three times. Also clean out the intake and throttle body of excess carbon as well. Put everything back together and start it. It's going to be hard to start and smoke like crazy, but that's OK. Then drive it rather hard for a few miles to burn out the remaining carbon.
If its still misses, then you have either a compression issue in the cylinders, or you have some stuck valve lifters. Hope this helps.
M.O.C
Platinum level certified Hyundai Technician
10 years experience.
13th Aug 2011, 08:30
There are a lot of great cars on craigslist... but unfortunately there are a lot lemons and problem cars being dumped on the public right now because of bad economy and unemployment issues with families.
What you will have to do... which is painful... you have to do what the last owner did and the owner before that... clean it up and sell it... and hopefully it falls in the hands of a kindly mechanic with deep pockets..