F115txra - will not restart warm

[erniefish]

Hi guys, my neighbor has a 2002 f 115txra, , it will not start after running to regular temp, it will crank,but not start, let it sit for 15 minutes ( cover off to speed cooling ) starts , runs fine. Also, new tach installed recently, and now works sporadically ( may be red herring) , new voltage regulator ,and various fuel system components have been replaced according to neighbor, any help would be appreciated, if further detail is needed I will ask neighbor for specifics , I am leaning towards vst issue , thanks again Eric

[erniefish]

Any ideas?

[rodbolt17]

when you turn the motor OFF, do you hear a rattling sound?
when you turn the key ON do you hear the fuel pump whine about 3 seconds?

[Pas Bon F115]

when you turn the motor OFF, do you hear a rattling sound?
when you turn the key ON do you hear the fuel pump whine about 3 seconds?

I have that same motor and Yes I think I hear a rattling sound when I turn mine off...what is that?

[rodbolt17]

that rattle is the ISC valve resetting to 100% in anticipation of the next start cycle.
its part of why EFI motors start at a faster RPM than idle.

[boscoe99]

that rattle is the ISC valve resetting to 100% in anticipation of the next start cycle.
its part of why EFI motors start at a faster RPM than idle.

Ever heard an F250TXR start? Ever thought about the RPM it turns long before oil has a chance to get to the motor. Makes me wince.

My Ford truck does the same. I hate it.

[rodbolt17]

the F350 is even worse on the flusher.
we can use it to scare the jeebers out of newbies though.

the worst is when you have replaced a powerhead or cyl head and the cam oil control takes a bit to pressurize.

[greasyshaft]

rodbolt,

What is the tapping like noise when starting the f50/f60/f70?

almost sounds gulping down a beer

[rodbolt17]

dunno.
typically a tapping on that motor is air in the mechanical pump.
typically it sounds like a collapsed lifter on an old chevy.