Toyota Repair: 90 4runner starting problem, light test, original computer

Question
I recently bought a 90 4runner v6 3.0 a/t 4x4 drove it home with no problems (around 45 miles).Once I was home with it the idle started to fluctuate and it died.When I tried to restart it it idled rough and died. This time it would not restart for several tries,when it did start it ran fine not rich or blubbery it just started like normal. I let it run for a while,shut it off and it started right back up no problem.I came out later to investigate it further and it started right back up,I let it warm up(so it would shift properly)drove it down the block came to a stop sign idled rough and died.Would not restart.Towed it back and let it set for a day retried to start and still nothing so i did the following checks.I sprayed it with either,it fired it up then died. Suspected fuel problem so I did the light test for injector pulse and it checked good but light was dim.Checked fuel pressure and was also good (49 psi). After that tried to start and it fired up like nothing was wrong(when i did the pressure test everything was hooked up but did not start checked  it with an adapter on the fuel rail).when I shut it off it would not restart.Thought maybe the injector pulse was too week so I changed the computer out with one off a 93 but still had the same problem.I did some research and found out that the ignitor sent a signal to the ECU for the injectors.I thought I had the problem figured out so I bought and installed a new ignitor.Started right up and ran great drove it across town shut it off and it started right back up.I Let it set for a few hours got in and started it up with no problems.I drove to pick my son up,went in leaving the vehicle idling, came back out after about 15 minutes drove to the end of the parking lot and stoped.The vehicle idled rough for a second then died now wont restart. To recap I have fuel pressure ,spark , injector pulse,and new ignitor,has original computer in it,never did run it with the one out of the 93 and not with the new ignitor. was not sure if 93 computer would work properly any way. sorry for such a long explanation but I want you to have all the info I know on the problem. thanks for your time,any help you could give me would be great.

Answer
About the only thing that I can think of that would cause this intermittent problem is the distributor, it has an RPM signal generator as well as a signal generator for engine timing, if either one of these has an intermittent problem it could cause this.  If the computer does not see the correct rpm signal at cranking the injectors will not turn on, the same is true if the timing signal is not correct, the best advise I have is to replace the distributor as I have seen it cause this problem.