This one is strange to me. Any help would be appreciated.
+4.3 tbi starts fine when cold. When new it started faster than you could
let off the key, takes about two seconds now...even if I wait a second for
the two second prime
+Turn it right off, starts right up
+Drive it until hot and turn it off....cranks but no run
+Spray in some ether....sputters then runs...never dies
+I drive this truck only a few K per year to haul trash, lumber etc.
+About 5K miles ago, reported EGR intermittently...I ignored it because it
was so rare and it passed emissions test.
+Last month, fuel pump went deader than dead with no notice. Checked
numerous ways....dead. Wouldn't spin even when connected to 12V
+I replaced the pump with a new pump and didn't mess with EGR until happy
+After a month, this hot start problem occurred and EGR code 32 more
frequent. Yesterday I replaced EGR (dead with vacuum pump) and solenoid
although okay and cleared memory.
+Today, still having the problem. Now I haven't driven many miles to
re-build fuel trims since the repair and clearing the memory ...but I'd
expect it to start hot.
Some tests results.....
+Fuel pump runs 2 seconds after ignition on...pulls 2 amps, takes 10 second
rest to reset (all as designed)
+Fuel pump runs when cranking....no fuel from injectors when engine hot
+I've even directly powered the fuel pump through the fuse connection (not
the OBD test connection) with a 10A fused ammeter before and during
cranking. The engine cranks and cranks with no fuel from the injectors until
I spray a tad bit of ether, then magically the injectors turn on and it
runs, never dies. Performs full strength when running implying good fuel
flow and pressure.
I don't think this is a fuel pump system related problem. Something is not
turning on the injectors during the cranking cycle until somehow it detects
the engine is running (i.e. ignition pulses with the switch in run, not
I'm not sure where the oil pressure switch fits into this, but I can achieve
high oil pressure during cranking hot so that should clear. Shouldn't matter
to the pump, because I've directly powered it...but it might matter to the
PCM if it is looking for oil pressure to turn on the modules. I'll go back
and check my diagrams for this feature.
There are no MIL codes now that EGR is fixed.
Any help would be appreciated.