Vintage Cars: 74 SL450 not starting, fuel pressure regulator, dissy

Question
QUESTION: Hi Ron,
I have a 74 Sl450 that I purchased recently. The vehicle arrived and was running but very rough, missing and blowing blackish smoke, but settling down somewhat and running  a little smoother at higher engine revs.

Did the usual, checked and replaced points plugs and condenser, checked leads and they all have same resistance, have spark, cleaned injector points and now will not fire or start at all.


Any clues?

ANSWER: makem sure you have spark.  if you do not -  could be coil,ground or ignition control unit.  Always go back to what you did , did you replace everthing back correctly? A bad ground will do this, a bad ecu will cause a no start.
If you have spark, check for fuel at the rails, if no fuel  , could be fuel pump


---------- FOLLOW-UP ----------

QUESTION: Thanks Ron,
Yes I have spark and believe we put it all back together properly. It did restart but was still running rough. Added new fuel as the car had been sitting around for a while, then wouldn't start at all so checked and cleaned injector points in bottom of dissy.
Now no go vroom at all.

Cheers,
any other suggestions greatfully received.

Answer
i would clean the in tank filter , if you have not have already , fuel filter  and make sure you are getting fuel to the rails, you could simply have a fuel delivey issue, partial clog or other.
Fuel pressure regulator could also be a culprit in this situation