Hello, Did the engine run for 15minutes 5 seperate times and then stall? Does the engine turn over now, or crank but not start? Why was the engine rebuilt?
Who rebuilt the engine and installed the main bearings?
How did you and your mechanic friend go about replacing the main bearings? Where were they purchased? Which bearings were used?
The reason I am asking is, the 4.7 engine takes select fit bearings. Which means there are different sizes, for the specific journal they belong to, it does not sound like this was done.
Crankshaft removed from the cylinder block.
Clean the oil off the main bearing journal.
Determine the maximum diameter of the journal with a micrometer. Measure at two locations 90° apart at each end of the journal.
The maximum allowable taper is 0.008mm (0.0004 inch.) and maximum out of round is 0.005mm (0.002 inch). Compare the measured diameter with the journal diameter specification (Main Bearing Fitting Chart). Select inserts required to obtain the specified bearing-to-journal clearance.
The main bearings are "select fit" to achieve proper oil clearances. For main bearing selection, the crankshaft position sensor target wheel has grade identification marks stamped into it (3). These marks are read from left to right, corresponding with journal number 1, 2, 3, 4 and 5. The crankshaft position sensor target wheel (2) is mounted to the number 8 counter weight (1) on the crankshaft.
NOTE: Service main bearings are coded. These codes identify what size (grade) the bearing is.
If this was not done, id be even more worried if it did start. The chance that you have the right bearing clearances in all 5 journal locations is slim to none. I would see if the engine will even roll over by hand.
Have you check fuel pressure and spark , compression,or injector pulse?
Compression and fuel pressure are checked with a gauge, injector pulse is tested with a noid light, spark is tested with a spark tester. Does the check engine light come on when it is running?
You will ned to start there, and have the code read. It is possible that timing is off, there is actually a code for cam crank mis- alignment. I have a feeling this will shed some light on the problem. You will either need to purchase a code reader, or have it towed somewhere. It is impossible to even guess at what is happening without some basic diagnostics ( codes, fuel pressure, spark, compression, injector pulse) Done for tonight, I'll check back tomorrow.
Let me know if you got that trouble code # XXXXX I can help you further.