1998 V70 Strange no start problem

[novaman83]

I have the problem only in the following scenario.
I drive a shot distance to the shopping center which is about 3/4 of a mile.
I park and shut off the engine.
Sometimes, when I try to start the car, it just turns over and will not start. If I wait, 30 minutes, it starts and runs fine. This happens only about 20% of the time.
The car has a po455 code (for quite sometime).
There are no other codes in the computer.
BTW, when operating the starter in this scenario, it sometimes cranks like it is fighting the timing. Then it cranks freely.
Question, could the cam or crankshaft sensor be bad and not put a code in the computer?
Can a fuel pump cause this problem?
I have changed the fuel pump controller with no change.
Could the po455 problem cause this problem?
Does a bad fuel pump put a code in the computer?
Thanks for any advice.

[abscate]

How old is the battery on your car? Fighting timing could just be a weak battery