Just bought a 2001 MC X30 with the MX LTR 5.7L engine. We took it out yesterday and it ran great for about 3-4 hours. Then it seemed as if some sort of Guardian Mode kicked in and would not let me rev above about 1500-2000 RPMs. I had to idle about a half mile back to the ramp and put it back on the trailer.
I went through many of the posts on here about fuel pump, fuel filter, vapor lock, water in the fuel etc and then ran across a thread about using the paperclip and check engine light to check the codes. I ran the test and all I can get out of it is a Code 12. I posted a vid of my testing if anyone can confirm my understanding of the light flashes of the Check Engine Light.
You can checkout the vid at http://justtesting.biz/mc01/vid001.3gp
If anyone has other tips to help troubleshoot, I would love to hear them.