Starting problems

[m5 sjs]

Hi,I am looking for some advice,I rebuilt my engine about a year ago,D24t,it runs very well,and it starts ok when cold,it sometimes needs a few cranks but generally its fine.My problem is when it is fully up to temp and I have been driving it for a while and then I switch it off and come back to start it after about 20 minutes later it is very reluctant to start.it takes a lot of cranking,sometimes I am afraid the battery will die leaving me stranded,once it does start it puts out a cloud of black smoke.so any advice would be appreciated.
Sorry for the long story,just wanted to be as detailed as possible.
Thanks

[RedArrow]

I had similar problems `warm-starting` an N/A diesel 240.
Compression was `significantly worse than good` :)) but it started in the mornings with colors of smoke. I remember clearly, that time I also played a lot with the `smoke-screw` of the IP :)) (fuel was turned up--->see black smoke). This Volvo was somewhat hard(er) to start after the engine got warm. WTF, I said. It actually cranked longer than it usually needed in the mornings.
Of course, it happened not* immediately after shutting it down, but like 30-60mins,2hrs later...
Replacing all glow plugs did not really help it, but setting up a so-ugly, manually operated glow plug on/off switch finished the job and problem solved.

(((Yrs later, huge old switch has been (re)moved, new small one hidden into dash. The old `temporary one`, 10x10cm, making constant noise on top of dash, It did look funny, I should have just used a sticker shown in pic.)))

You might need some more glowtime!
Worth a try saving the starter, trusting your 5sec finger-power so car may start much easier when warm, with a makeshift manual glow system.

I guess you don`t see the orange glow-plug light coming ON when engine is warm: a d24 brain `thinks` that temps are still high enough to start withOUT the plugs. wrong. Chances of a proper&successful start (withOUT the plugs) get slimmer as time goes by (engine cools).

[745 TurboGreasel]

Put a clear hose on your fuel return, and watch it for bubbles, fair chance a seal or hose has shrunk a litle since your rebuild. Check every fuel hose clamp.

Bend 6-8" of #10 or bigger wire into a U...
before warm starting the car, pop the hood, and use it to jump the two big terminals on the glow relay(some might say to unplug the control plug from it first), count to 10, then see if it fires right up. If so, adding a button will help mask the real problem.

[m5 sjs]

Hi,thanks very much for your replays,I will try those few things out and see.
Much appreciated