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No spark

Okay, making progress.
Great!

I'd unplug the injectors, to keep from filling up the cyls, and keep spinning it by hand until you have working spark.

First off, unplug the center lead from the disti and fix it next to a shock tower bolt, or something easy to see, then spin by hand. Cleanflametrap has a nice picture showing a magnet and one of the single-wire valve cover plug wire holders setup for spark testing.

If you have spark, then the problem is between the end of the coil wire and the plugs. If not, you could try measuring the voltage between pin #1 of the coil and Battery + post while spinning by hand. This will be +0volts most of the time, but should briefly blip up when the coil is charging during the dwell time. Dwell time is roughly 0.01 seconds, so it's hard to see the blip with a meter.

If you don't see the meter twitch, you can try the same thing with the EZK to powerstage signal if you can probe it when connected. You want to probe powerstage pin #5. The EZK to powerstage wire, for a '87 740, is green (sorry, I misread GR as OR initially) but I don't know what it is in your harness. [Edit: probe this one to the battery - post, the EZK signal is 0v and pulses to +5v during coil charging.]

For the fuel pumps, they draw a pretty high current so you want them powered through a relay, instead of drawing all the power through the ignition switch. The harness that you have includes the relay, you just need to run the fat yel/red wire to fuel pump fuse(s), assuming that they're present and wired to the pumps.
 
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Good work! If the hall sensor is triggering and the signal for that is sent to the fuel computer you get the pulsing on your injectors. Now if you still don't have spark. You have to test the signal from the power stage to the coil. Is there anyting else connected to the red white wire on the coil? Besides the coil and the powerstage?

If there is switching then the secondary part of the system from the coil to the coil wire, dist cap, rotor are next along the path.
 
Great!

I'd unplug the injectors, to keep from filling up the cyls, and keep spinning it by hand until you have working spark.

First off, unplug the center lead from the disti and fix it next to a shock tower bolt, or something easy to see, then spin by hand. Cleanflametrap has a nice picture showing a magnet and one of the single-wire valve cover plug wire holders setup for spark testing.

If you have spark, then the problem is between the end of the coil wire and the plugs. If not, you could try measuring the voltage between pin #1 of the coil and Battery + post while spinning by hand. This will be +0volts most of the time, but should briefly blip up when the coil is charging during the dwell time. Dwell time is roughly 0.01 seconds, so it's hard to see the blip with a meter.

If you don't see the meter twitch, you can try the same thing with the EZK to powerstage signal if you can probe it when connected. You want to probe powerstage pin #5. The EZK to powerstage wire, for a '87 740, is green (sorry, I misread GR as OR initially) but I don't know what it is in your harness.

For the fuel pumps, they draw a pretty high current so you want them powered through a relay, instead of drawing all the power through the ignition switch. The harness that you have includes the relay, you just need to run the fat yel/red wire to fuel pump fuse(s), assuming that they're present and wired to the pumps.

That is how I'm checking spark.

Between coil pin 1 (red/white) with it unplugged and battery + the meter sits at battery voltage with no blip. Between powerstage pin 5 (probed through the back with it connected) and battery + it blips from 60mv to 75mv when I turn the dizzy.

Nothing else connected the coil. I have two cheapie powerstages in addition to the old Bosch one. Only difference I can find is that while the bosch has about 10kohms between coil pin 1 and ground the cheapies have an open circuit. Neither of these match what mrak said.

For the record, I checked resistance between negative and ground like you asked. With the ignition off it was 18 - so basically nothing, and with the ignition on it was very high.
 
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Oop, I probed powerstage pin 4 not 5. Pin 5 sits at battery voltage, same as the coil wire. Popped the old EZK back in and no change.
 
For checking the coil pin 1, leave it plugged in.

Sorry, for the powerstage, I snuck in an edit on you:
[Edit: probe this one to the battery - post, the EZK signal is 0v and pulses to +5v during coil charging.]

If you measured +12v between pin 5 and battery + post, then this is equivalent to measuring 0v between pin 5 and battery - post. If you re-measure with battery - post, it may be a little more sensitive and show the blips.
 
Since you can get to the back side of the powerstage pins, here's a few more voltages to check. With everything connected (injectors can be unconnected) and key on, measure between powerstage pins and battery - post:
pin 1 - red/white wire to coil, 12volts and, depending on meter, may blip when turning disti.
pin 2 - black ground, 0volts
pin 3 - shield, probably 0volts
pin 4 - red, +12v power
pin 5 - green, spark signal from EZK, 0volts and may blip when turning disti.

One other thought, check the top of the coil and find the embossed pin numbers in the plastic. Pin 1 = red/white wire, pin 15 = blue (?) power wire, yes?
 
Since you can get to the back side of the powerstage pins, here's a few more voltages to check. With everything connected (injectors can be unconnected) and key on, measure between powerstage pins and battery - post:
pin 1 - red/white wire to coil, 12volts and, depending on meter, may blip when turning disti.
pin 2 - black ground, 0volts
pin 3 - shield, probably 0volts
pin 4 - red, +12v power
pin 5 - green, spark signal from EZK, 0volts and may blip when turning disti.

One other thought, check the top of the coil and find the embossed pin numbers in the plastic. Pin 1 = red/white wire, pin 15 = blue (?) power wire, yes?

Measured all 5 from the back of the powerstage connector to battery -, ignition on, and I got what you wrote (12v on 1/4, 0v on 2/3/5) but no blipping when turning dizzy. Coil is connected correctly.
 
OK, seems to be no spark signal from EZK to powerstage, or the blip is too small to catch on your meter. I think you can check for a blip from EZK with the powerstage unplugged. You'd measure voltage across harness connector pin 5 to battery - post, while spinning disti (key on). Anything? [If it were me or ZVOLV, this would be a great time to put an oscilloscope on that pin.]

Next, turn if off, unplug the EZK and measure resistance between powerstage connector pin 5 and battery - post. Since EZK is unplugged, this should be an open circuit. If the wire is shorted somewhere, it will usually show some resistance to ground.
 
I can usually see the trigger signal as a varying voltage on a digital meter if the metter is fast enough. Usually looks like it varies from 0~3v. A scope would be nice though.
 
OK, seems to be no spark signal from EZK to powerstage, or the blip is too small to catch on your meter. I think you can check for a blip from EZK with the powerstage unplugged. You'd measure voltage across harness connector pin 5 to battery - post, while spinning disti (key on). Anything? [If it were me or ZVOLV, this would be a great time to put an oscilloscope on that pin.]

Next, turn if off, unplug the EZK and measure resistance between powerstage connector pin 5 and battery - post. Since EZK is unplugged, this should be an open circuit. If the wire is shorted somewhere, it will usually show some resistance to ground.

Okay, so it is blipping up to about 3v at pin 5 with the powerstage unplugged but with any powerstage plugged in it sits at 0v. Open circuit to ground with ezk unplugged.
 
Hmmm..... Seems like you're good to the powerstage, but then goes bad. I'm trying to think of something that fits your symptoms and part swaps, but don't have anything likely.

A bad powerstage shouldn't drag down the input signal. It would more normally fail with either the output shorted to ground, or no output at all, but the input signal would be fine.

If you disconnect the coil from the powerstage (disconnect and tape both pin 1 and 15 on the coil), with power stage plugged in, does it blip on powerstage input or still nada?

Edit: I'm still suspicious that plugging in the powerstage causes problems. This is a longshot: With key off, ezk unplugged, and powerstage unplugged, measure the resistance between pin 5 and the other pins in the powerstage connector. It should be open circuit for all.

Unless someone else has a suggestion, it sure seems like it's time to try yet another powerstage if the above tests don't find anything. The powerstage is basically a beefy power transistor on a heatsink, so most any brand, or junkyard used, should be OK.
 
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Hmmm..... Seems like you're good to the powerstage, but then goes bad. I'm trying to think of something that fits your symptoms and part swaps, but don't have anything likely.

A bad powerstage shouldn't drag down the input signal. It would more normally fail with either the output shorted to ground, or no output at all, but the input signal would be fine.

If you disconnect the coil from the powerstage (disconnect and tape both pin 1 and 15 on the coil), with power stage plugged in, does it blip on powerstage input or still nada?

Edit: I'm still suspicious that plugging in the powerstage causes problems. This is a longshot: With key off, ezk unplugged, and powerstage unplugged, measure the resistance between pin 5 and the other pins in the powerstage connector. It should be open circuit for all.

Unless someone else has a suggestion, it sure seems like it's time to try yet another powerstage if the above tests don't find anything. The powerstage is basically a beefy power transistor on a heatsink, so most any brand, or junkyard used, should be OK.

Coil unplugged makes no difference. With EZK and powerstage unplugged pin 5 shorts to pin 3, open circuit for the rest. In the dbarton harness guide it says pin 3 is a shield for pin 5.

I tested the rest of the pins though and found that pin 2 and 4 are shorted. Pin 2 is connected to the manifold ground. Pin 4 is ignition coil positive. But when I plug in the EZK and turn ignition on I get 12v at pin 4 and pin 2 is grounded.
 
I tested the rest of the pins though and found that pin 2 and 4 are shorted. Pin 2 is connected to the manifold ground. Pin 4 is ignition coil positive. But when I plug in the EZK and turn ignition on I get 12v at pin 4 and pin 2 is grounded.
Without looking at a wiring diagram, and without seeing how your harness is built, this is probably OK. Pin 2 and 4 are main ground and main +12v. I'd guess that even with EZK unplugged, that there are other components still wired up. If you want to check, on the lowest resistance setting, hold the probe tips together and write down the value. Should be close to 0.0 ohms. Now, re-measure 2 to 4 (ground to +12v). I'd expect it to be 10ish ohms, but that's just a wild guess.

With EZK and powerstage unplugged pin 5 shorts to pin 3, open circuit for the rest. In the dbarton harness guide it says pin 3 is a shield for pin 5.
I think you've found it!!!

3 shorted to 5 is very bad, the shield should connect to ground and nothing else. If it's shorted to pin 5, it grounds the spark signal from EZK to powerstage, and you'll get no spark. I'd guess that the accident damaged the cable and either the accident, or the repair, caused the short. I'll find a picture of shielded cable tomorrow -- it has an insulated center wire surrounded by a metal woven shielding sleeve. They should not contact.

Can you peel back the plastic harness sleeving a couple inches? If so, the quick&dirty test would be to cut the pin 3 shield wire a couple inches from the connector (do it so you can reconnect it later if needed). The shield connection isn't necessary for startup, but might be needed to prevent occasional misfire.
 
I think you've found it!!!

3 shorted to 5 is very bad, the shield should connect to ground and nothing else. If it's shorted to pin 5, it grounds the spark signal from EZK to powerstage, and you'll get no spark. I'd guess that the accident damaged the cable and either the accident, or the repair, caused the short. I'll find a picture of shielded cable tomorrow -- it has an insulated center wire surrounded by a metal woven shielding sleeve. They should not contact.

Can you peel back the plastic harness sleeving a couple inches? If so, the quick&dirty test would be to cut the pin 3 shield wire a couple inches from the connector (do it so you can reconnect it later if needed). The shield connection isn't necessary for startup, but might be needed to prevent occasional misfire.
Boom. Pushed pin 3 out and I got spark.

Put it together and turned the key, nothing.

Somehow the little button in the distributor cap fell out, popped another one on and now it sputters but won't roar. I can't see the timing mark cause it's too bright right now, so I dunno what it's at. Injectors are firing and fuel pump is running, but it's a new setup and I don't have a way of checking the pressure.
 
Injectors 2 and 3 have no pulse at all. Tried a different ECU. No accident damage to any of the wiring harness other than the powerstage.
 
What are you doing to check injector pulse?

Does it run on brake cleaner?

Multimeter on the pins. Runs on brake clean.

I have a crappy connection somewhere that I can't find. I was messing with it and the FPR started buzzing and now it doesn't do anything. No injector pulse at all in 1/4 anymore.
 
Runs on brake cleaner!!! Great! That means your spark is alive and well. You should be able to keep it running on brake cleaner by pulsing it into the throttle body.

The wiring commonly rots out under the intake manifold. I would put one end of the meter on a terminal at the injector plug and the other meter lead at the ECU end of the circuit and wiggle test the wiring harness and see if resistance changes, or if there's an open circuit.

DO YOU HAVE POWER TO ALL FOUR INJECTORS??? I'm not certain a meter would show the switching. A noid light or test lamp would be better.
 
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