Fuel pump and fuel pump relay replaced after 115,000 miles. On occasion, engine will not start, but will after 10 minutes. No security light ever appears (passlock) and no engine trouble codes are recorded. After starting, engine runs smoothly and normally... this may not occur for another 2 - 3 weeks. This never occurred previously until the fuel pump was replaced.

 

Well start there if you are certain that its related to fuel pump and relay replacement. It's possible that there is a poor connection in the fuse block where the fuel pump relay is. Is it a crank no start? Or a no crank no start? Both are very different and require different approaches. You might want to have dealer do a full sweep of the vehicle control systems and see if there are any codes in the system that could possibly be causing your no start condition.

 

Dealer performed repeated " sweeps " and NO CODES were found in the system. Starter always turns over easily when ignition key is turned on ... whether the engine starts or not. Dealer kept the truck for one (1) week and it never failed to start after numerous daily tests ... unable to repeat the " no start " condition.

 

Yeah the only way to tell is to be back probing fuel pump power and ground circuit when vehicle does not start and see if power is getting there or not. Otherwise intermittent problems are the most difficult to find and properly diag.