Volvo: starting, fuel pump relay, fuel pumps

Question
I can't get my 1981 240 DL with a B21F engine to start. It wants to start, but will not turn over. I have replaced the fuel filter and the fuel pump relay and checked the fuses, but it still will not start. I am about to replace the fuel pumps, but want to see if there is anything else to check before I replace them. Any other fuses or relays?

Answer
I'm not sure how the engine can be close to starting without turning over.  Do you mean to say, it turns over, but will not catch?  The first thing to do is check to see if you're getting a spark while the engine is turning over but not starting.  Unscrew one of the plugs and hold it close to the chasis to see if a spark arcs to the metal.  If it is live, next check the fuel injectors, by pulling one and seeing if it squirts fuel while cranking the engine.  You're probably not getting one or the other of those, so once you find it, begin tracing back into the system.