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Hi this is Timbre4, here at New Caney TX High School today to observe and interview students using Performance Center. Jack Garrett is the instructor and there is a thorn in his side vehicle he could use some help on:

Hello all, thanks in advance for any help you can offer. This 1987 Nissan PU has the Z24 2.4L 8 plug engine that has been recently rebuilt. The issue is it initially ran great after the rebuild, then abruptly cut off. Moving the distributor couid bring back to normal or act as if it jumped time. Suspect the CPS in the distributor. (LED wheel type)

Has anybody seen a way to verify whether this sensor is good? Is there anything between PCM and crank sensor terminal that could be bad? Thinking if not just wiring, maybe there's a component I just can't see?

Does the vehicle start? If it doesnt then is spark missing? What about noid at the injectors?

You can test the sensor just like any other. Use an o-scope. You'll need a quick one to get the 360 pulses. Should have a square waveform output. These are pretty bulletproof and don't usually fail in the way you are thinking. I'd first double check mechanical timing if you haven't already. Get all the marks lined up and see if dist is pointing to number one. Make sure the pin for the gear hasn't sheared and the gear spun. Not likely, but you never know.

If it starts when the dist is rotated, something is out of time. Usually the relation to the crank sensor and the rotor is pretty constant. When you scope the signal, use a dual trace and also check for the cylinder pulses. One cylinder pulse to every 60 crank pulses, if you can picture it.

Should look like this.....

in the way, way, way back machine i believe that moving the distributor is like dragging the cam sensor wire along the block to make it sense an interruption and make it fire. the distributor i believe is compared to the thick film style of yester year. don't overcomplicate it. moving the distributor may just be giving the system the interruption it needs to fire.

Thanks I knew you guys would jump in! Jack's school has security settings which required him to ask for managerforum.net be allowed as an exception, hopefully by today.

He may have reviewed this from home last night and I'll check that he's back with more info as time permits. Somebody's waiting for this fine jewel so he's motivated!

Suite hope it works out

Any news yet?

Thanks for all the good info. Sorry for delay, I was mistakenly blocked again by our tech dept. I am back in business now. I tried moving the distributor as suggested and although I had done this before but with very small steps, this time I was more aggressive and it began running. It is still somewhat ragged but I think it may be a wiring connection at the base of the distributor. I fixed that and it is now obviously a timing issue. Thanks to all of you and a little luck I may have it outa here today. Small movements to set time seem to be working. It is sure good to have a source to get help.

If you need any help let us know or any questions. Good luck