The car is a 1988 240 sedan with a B230F motor. This car has always required a few more than normal cranks during cold starts, but it does always start. Last week it stopped starting!

It has spark, timing belt looks good and I can smell fuel during cranking. My little injector test light shows that the injectors aren't getting pulsed. The light lights up once during cranking. My '87 240 wagon, which does start, makes the test light blink rapidly during cranking. From this I am assuming that there is some fault with the injection system. What could it be? Is there any thing specific I should be looking at?

Thanks in advance!