It has been a while since I have had time to do anything on the forum. Way to much time at work. Seems like it I dont have a choice now. My 89 montero 2.6 with a rebuilt engine (about a year old) has been cutting out on me after I drive it for about 20 miles and is under a load. I changed sparkplugs to NGK (the ones I pulled out looked great though, changed them bcs they were autolites). Changed the Dist cap and rotor button. It is still cutting out though. I have used the stuff to get rid of water in the fuel lines also. I believe the thermostat is stuck open, I am changing that today and the fuel filter. I also changed the air filter. My only other thoughts would be the fuel pump or the coil. I also installed new plug wires when I installed the rebuilt engine. I did some research on this subject and found a couple of posts where some people had the same problem but there was no clear solution.