Well I purchased my 93ls 4k miles ago it has 170k miles on it. I went and took the family to a amusement park yesterday that was 360 miles away round trip yesterday. The car seemed to run just fine on the way there but when I started the ls to leave it started misfiring badly. I needed to get some gas so I stopped in the local station and filled up. I then found out I only got 18 mpg versus the usual 22-25. I will list the symptoms below.
* Running very rough
* Does not have any power, I would compare it to when you start a car in to high of a gear when trying to take off
* It could not maintain speed up any sort of hill
* My tachometer was not consistent, it would bounce all over the place
* Since the first day I bought it the speedometer has been 20mph slow but earlier in the week it magically started working correctly.
* When I first opened the hood, I saw some smoke coming off the rear of the engine.
* No check engine light.
*10 mpg
If any of you know where to start I would greatly appreciate it. I haven't had time to go pull a plug and see what it looks like so start giving me an indication of what might be wrong. It was a tough drive on the way back but we made it safe and sound. thank for any help.