Started running rough, turned it off, won't restart

[jaymuch]

My wife filled up the tank, then got on the freeway going 65-70 mph. After 10 miles it started running rough, and continued to get worse. She pulled over about a mile later and turned off the car. It would not restart. I checked crash switch and replaced fuel relay and fuse. I checked the fuel filter, the larger hose seemed clogged, I could not blow through it, so I replaced the fuel filter. Still no fuel when I turn the engine over. But here's the kicker, I checked compression, #5 and #6 have 190 lbs, and #1, #2, #3, and #4 all have zero compression! No water in oil, no external evidence of blown head gasket. How is this possible? Could the "fail safe mode" have something to do with this? Any ideas would sure be appreciated. 2002 Ford Explorer XLT 4.6 with 138,000 miles.

 

[tower]

You said it is a 4.6, so did you check the compression in the other 2? If it is a 4.0 you may have timing chain has issues.

Are you getting fuel pressure?

 

[jaymuch]

You are right, my mistake, it is a 4.0 six cylinder. I disconnected the fuel line from the tank and turned the engine over and no fuel came out of the hose, seems to indicate fuel pump problem. Can the fuel pump be checked by hot wiring the connection on the rail under the passenger seat. If so, which color is positive, and which is ground? But I don't know why I have zero compression in 4 of the cylinders, all three on the drivers side are at zero, and just #4 on the passenger side. Seems like if it was a timing chain issue, all 3 cylinders on a side would be zero. Also, it seems strange that the fuel pump would go out at the exact same time as a timing chain or other issue involving compression. Is it possible that the fail safe temperature sensor is bad and the vehicle is stuck in "fail safe mode"? Is it possible to verify the fail safe mode is not preventing the engine from running? Sorry for all the questions, I am just very puzzled. Any help or input is sure appreciated.

 

[vipersinu2]

probally timing chains, they are a piss poor design.

open oil cap passenger side, have somebody crank engine, look down at cam shaft see if it is spinning.

driver side I thing you will have to remove valve cover to see cam shaft.

 

[jaymuch]

Thanks for the tip. I will check it out and let you know what I find.