But a discovery that had a bad head gasket. Fixed that, put in a new fuel pump water pump idler, and radiator. Discovery was running great and then died while I was driving. Pulled over wait a few minutes and start right back up. Today when I drove it and parked it it came back eight hours later it would not start. Anybody have any ideas?

 

what type and year truck ? possible crank shaft positioning switch

 

It could be just about anything based on your description. More details are required.

 

I forgot to put in the year. It is a 99, automatic, I'm not sure what size v8. I think it is the smaller motor.

 

ok, were getting there 1999 is it a D1 or D2. they made both in 1999. Are the door handle flush or do they protrude?
flush would be D1 , protruding would be a D2.

 

Thanks for all the good advice. It was the Crank position sensor. My 99 has 153k miles. I put in a new fuel pump, the crank sensor. I serviced the trans. I want to do a base repair on stuff that generally goes bad. I have not done the fuel pump relay or the heater core. Any idea on what I should do next? How about the alternator?

 

It usually either works or it doesn't. Check the voltage using a multimeter (<$10 a Harbor Freight); all electrics on such as high beams, AC on high, etc, on and you should still get at least 13.5 Volts as read across the battery terminals. If you do, the alternator is working properly.

 

at the top of the d2 section is a sticky called major service you could use that as a guide line.
Im glad the CKSP helped you out.