Wont start the first time when warm!!! -_-

[Brolin]

So i bought a 88 325is with e motor in it dont know why dont ask haha, the car always had the issue of not starting the first time when i drove it for a while, turns on first time when cold like before i drive to work in the morning
i bought a m20b25 motor rebuilt the whole motor from ground, new plugs, wires, rotor, cap, injectors.... everything except the starter and alternator
buddy of mine told me that it might be the starter he mentioned heat soak problem
Any thought where to look

[tomstin]

the car always had the issue of not starting the first time when i drove it for a while,

Does it crank? If it doesn't crank, check all the cables, both power and ground to the starter. If all those are good, then I'll bet on the starter.

If it cranks, I would check fuel pressure (could be junk clogging the in tank pump sock). Then crank position sensors.

When it doesn't start, how long does it take before it will start?

[Brolin]

Does it crank? If it doesn't crank, check all the cables, both power and ground to the starter. If all those are good, then I'll bet on the starter.

If it cranks, I would check fuel pressure (could be junk clogging the in tank pump sock). Then crank position sensors.

When it doesn't start, how long does it take before it will start?

So the crank position sensor is new and fuel pressure is good, usually it will start first time when engine is cold and then ill drive it like 40min-1hr and when i shot off the car and try to start again it will take a cool 10 seconds to start but it will start no matter what i usually just let go when it wont start the first time so i dont mess the starter. Could it be voltage regulator in the alternator because i forgot to mention my alternator doesnt charge as fast as it should

[TobyB]

Using smaller words:

When it doesn't start hot, does it go "wrrr wrrr wrrr" for a while before it goes "vroom"?

Or does it not go "wrrr wrrr wrrr" at all?

Because those are 2 very different problems.

t