Ok, from what you are saying all the spark plugs are firing
in the car and
in order, right? And, you did check the distributor cap and rotor for any funny business (cracks and awful gaps and so on).
I am basing a lot of my suggestions on what I know about Bosch LH fuel injection system (it worked enough to help a friend get his JDM VETC swap working in his Honda
), so I may be missing something. In any case, both the injectors and the ignition should be getting info on when to fire based on where the crank angle sensor is. So, what I want to do is to see if the problem is affecting both or just one of them. i.e. if all the injectors work on the bench but when you crank the engine without spark plugs the two middle ones do not spray, we may have some electrical issues in the injection system. The same goes for the spark plugs; I have seen a car whose rear cylinder spark plug would not fire. It turned out to be a bad distributor hall sensor.
Now, when the key is in the ON position, each injector should be seeing 12V on its power wire. The ECU turns each injector on by grounding it; this is much easier to do electrically speaking than flicking the 12V side. Of course, once the engine is turning, if you measure the voltage across the two terminals in the fuel injector, it will show less than 12V because it is pulsing... kinda like on the primary side of the ignition coil.
Before we go any further, I would suggest to invest on a noid light. The cheapest set I have seen is the
Harbor Freight one. You can then connect it to a fuel injector connector and then see if it flickers/pulses. If it does, you know the ECU is telling that injector to fire. If not, you may want to check the continuity between the ground wire at the injector and, say, the engine (it is a good ground) while cranking and see if it flickers (or turn the key to the on position and turn engine by hand until the ECU grounds that wire). If that wire is not being shorted to ground, we can do more tests.
I feel like I may be losing you, so let me go back to basics: you need compression, fuel, air, and spark. So, make sure each one of them is right. For spark, test for spark at the offending cylinder. For fuel, test for power to the injectors (noid and multimeter) and then for the injectors opening and spraying fuel.
The crank sensor angle thingie is something that has a unique mark to identify, say, the top dead center for cylinder 1 (or whatever reference they want). Then, it has a way to measure how many degrees the crank has moved per unit of time (a second?). With these two pieces of information, the ECU can figure out how fast the engine is turning and where the pistons are. This way it knows when it is time to spray fuel and light the combustion chamber.
Linear Mode
