So recently I changed my valve cover gaskets. In doing so I removed the distributor not knowing anything about ignition timing. After completing the job I reinstalled everything and then could not start the car. The crank was sluggish and no start.

I immediately researched and thought that my ignition timing was just off. I wen ahead and replaced all the spark plugs and wires and since this car is new to me and is a project I went ahead and replaced the ignition coil and upgraded the ignition relay to PRW2 with an adapter that I got from PastPowerParts. I also replaced the Crank Angle Sensor along with the other insides of the distributor (rotor & plate) as well as the cap. I also changed the fuel filter and did an oil change.

After completing all of this I tried to start the car again. This time the car cranked much better. The starter was quick and I thought for sure it was going to start, but no such luck. While cranking I can hear the exhaust sputter a bit and backfire. I'm just not really sure if this means anything.

As a side note I did find that my negative battery wire was not bolted to the car, which makes me believe there was no ground. Could I have fried my ECM???

I took it out of its compartment to inspect it. The Red & green lights come on but when I tried to switch modes the little screw broke so now I can't reset or diagnose anything. (35 years of corrosion I guess)

If anyone has any insight on this I would greatly appreciate the help. Does the backfiring while cranking mean anything? What do you think the issue could be?

Ok, so I have an update.

One of my suspects was the fuel pump. The reason I didn't look into this sooner is because it didn't relate to the job I did before the car wouldn't start, and also because I didn't have a fuel pressure tester. I stated before too that I was concerned about the ECM.

I managed to find a refurbished ECM that was an exact fir for my car. I ordered it and replaced my old one. On the new one I was able to run a diagnostic and I had no errors. Now I decided to turn my attention to the fuel system.

I purchased a fuel pressure testing kit and did some research on what is normal for the 87 Z31. The fuel pressure should read 38psi with the ignition set to the "On" position. I connected the tester, primed the pump and set the ignition to "on" and the meter read 30psi. So now I feel pretty confident that the fuel pump is my culprit. The pressure regulator has no leaks and I feel like it would be unlikely to have a sudden No Start because of injectors. Also I had used Chevron Techtron fuel system cleaner on the tank of gas and now the car had been depleted to a quarter tank when the No Start occurred. I feel like the pump must have gotten gunked-up. I'm going to probably not only replace the pump but maybe drop the fuel tank and give it a thorough cleaning.

I'm curious if anyone has any experience with this and might have any thoughts?