I have an 89 vert that I have owned for 4 years. I bought the car in Indiana with a bit of rust, the worst part being in the doorjamb. About a month ago, my idle was all over the place. I attempted a TPS adjustment, no help. I purchased a used IAC valve and replaced, again no help. So, I took the car to the local mazda dealership. I was told that I needed a new factory IAC valve @ $920. I decided not to spend that on it ecspecially since I thought it was OK anyway. They did however tell me to crimp off the airline going to the IAC valve and it would "fix" the problem. I did this and drove the car about 400 miles and the split air pipe blew off. I don't weld or have a lift, so I took the car to an exhaust place and asked them to replace the split air pipe. I also asked them to check the cats. Completely clogged, so they were replaced. The car ran perfect for 2 days, no idle issues, nothing. I started the car up on the 3rd day, and since this is my 3rd 7, I freaked. I knew that the engine was gone.Just to be sure, I took the car back to the exhaust place for them to check to be sure there were no more clogs, and alas, clear as a bell. I then took the car back to the dealership for them to definatively diagnose it. I was told that the engine is gone due to carbon buildup. I have fought with the dealership because they misdiagnosed the problem, but they are also telling me that I am running the wrong plugs. So, they are willing to eat 1/4 of the cost, but as I don't have time or means to replace the engine myself, it will cost me $3400 after their 25%. So, my question for you guys is, do you think that I should pay the money for a "new" rusty 18 year old car. If I decide to do it, I would like to get more horsepower out of it. I haven't really worked on any of my 7's for 10+ years so there is alot that I don't know. Is it possible to do anything inexpensively that will get me more power? Of course, I could put the $3400 plus $500-$1000 that I would get for the car as is and put it towards an FD. Anyway, comments?

 

Carbon locked?

Search the forums, you can use marvel mystery oil, atf, water, seafoam, etc etc, to fix this, research and pick which one you want to do. There is also a video on youtube i think about carbon build up. It's easy to get it to run again if it's carbon locked. Dont expect it to run TOO much longer though. Although you can probably have rotaryresurrection install and rebuild the engine for you for less than the dealer, if he has the time to right now. He is in tennesse. I would expect it to be around $2200 if he does it for you, however, if you get an engine hoist, removing the engine isn't al that hard, and you could have him tear down the long block and rebuild it for $1500 maybe? Go to his website.