My 02, 4.0 with 141K miles has been hassle free since the day I got it. I've put 0ver 100k miles in 3 years with no problems.
About 6 weeks ago it got hard to start and the check engine light came on. Took it to my mechanic and he replaced crank sensor and cam sensor. Started fine and ran great. The next day check engine light started flashing while I was doing 60-65 and goes into limp mode. Pull over and turn it off and back on and it runs fine. This has been going on since then. Each time it get multiple misfire codes, all cylinders. Some days it runs fine and others I have to restart it 3-4 times. The only consistent thing is it has not done it at speeds less than 50.
I replaced the crank sensor thinking we got a bad one, put in new plugs, replaced spark rail, replaced computer (another mechanic said it was bad). I have run premium gas with gas dry and it's still does it. I've checked for leaks in the intake manifold, cleaned out the throttle body. I read another thread where someone said to run seafom through it to get the carbon off the valves.
What am I missing? The trained mechanics can't seem to fix it. I have worked on my cars all my life and have never had a problem I could not fix. Any suggestions??