I have a 1999 Mitsubishi Eclipse 2.4 SOHC GS Spider, Automatic, it’s not top of the line with a turbo, but it’s my baby. I recently noticed while the car was stopped and running, that the idling was sputtering, and the car is almost drying. I had the car diagnosed and the #4 cylinder was misfiring. I replaced the Plugs and wires; problem went away for about 2 weeks, but soon returned. Took the car into the shop; Greg’s Japanese Auto in Chandler Az., where they said the #4 fuel injector was firing intermitting, and not providing enough fuel. The shop also said the number #4 cylinder was running about 100 degrees different that the others. I order one off line and had them replace it. They replaced it, but it did not fix the problem, so it was removed. They are now telling me that the #4 exhaust value is leaking by and causing the problem. They wanted to charge me $2000.00 to rebuild the #4 exhaust valve to fix the problem. I am taking the car to a Mitsubishi dealer for a second option, because I don’t have confidence in this shop, because they said it was the Plugs and Wire, then the Fuel Injector, and now the Exhaust value. If anyone has had this same problem, or know of a fix, please let me know. This car has never over heated, and I had the timing belt and water pump replaced at the time the new plugs where add, but I am still having the same problem. The problem was there before replacing the timing belt, water pump, plugs and wires. Timing belt and water pump was replaced because the car is at 84,000 miles.

 

what does the spark plug look like when you remove it, is it carbonized, white, melted? what type of fuel injector did you put in, you must use a low impedence fuel injector on these cars or they wont run properly........ do you hear a lifter ticking noise when the car is at idle? what heat range plugs are you running.......

 

I checked out the Plug and the ones I put in where Bosch Platnuim plugs, I only had them in there for 2 weeks, but the plugs look okay to me, still new looking, but one does look a little white. But I had the dealership replaced them any ways with the correct type for the car. The fuel injector was the basic OEM part for the car, pretty sure it was the same injector that is on there. I do hear a ticking noise when the car is idling and have been hearing it for awhile; I just was not sure where it was coming from. I will check it out when I go home for lunch to make sure it is ticking. Thanks for the feedback.

 

the lifter tick is a common problem in our cars, if the valve is not seating properly i guess exahust could leak out and cause it to missfire, the tick is caused by the oil squirters being to small and not lubricating the lifter well enough, if the valve got to hot i suppose it could have caused it to bend or warp causin the exahust leak, however im not a machanic so im not positive of this....... oh, and it shouldnt cost 2 grand to fix.......... id say probly 5 -600 tops seeing as its a problem with the valve train, not the cylinder........

 

Yea, that’s what I figured on the cost also. I check out the car and there is a loud fast ticking, but then it stops for about 2 or 3 minutes, then it starts back up. I remember the mechanic saying that he did a compression test and he got good reading across the board. Then he said he ran smoke thru the system and noticed the smoke coming out at some port and that’s how he determined it was a bad exhaust valve. I also looked at the spark plugs again, and they do look a little burnt around the edges. Thanks for the feedback, I am pretty new to working on cars, but I guess I am getting ready to learn a lot. How hard is it to do you, wont mind getting the experience if it’s not that hard?

 

Thanks 1398spdr for the common lifter tick problems, I found alot of people that used this trick to remove the carbon build up and fouled valve cleaning and it worked. I will try it when I am off later this week to see if it works.

http://www.outreach.psu.edu/users/res122/DSM/

 

i used an additive to the oil before i did an oil change and that took care of it for about 2 months, take some ordinary engine (cylinder, valve) cleaner and put it in where you normally fill the oil, let it run for 10 to 15 min and it will pretty well clean the valves and cylinders....... when i was done i drained the oil and looked at the valve train, it looked almost new.... i also put some in the fuel tank to clean the injectors and it worked great, you can definatly feel the increase in hp just from getting the carbon off everything and your engine runs so much better...... if you got any other questions, feel free, im off tomorrow and im gonna do an oil change so im sure ill be on here at some point.............