Crank no start no rpm 96 5.7

[Kevmore007]

Sorry to hijack the thread, but maybe we will all figure this out together.
I replaced the crank sensor, and hooked up a scanner and am getting rpm, and spark, and it coughs a bit now. I am waiting for the snow to melt because it's outside and it snows in March and April and May sometimes June. The next thing I am going to do is check TDC and find out if the distributor isn't off by a tooth.

 

[Kevmore007]

Update. I can make the coil fire if I take the sensor out and take a screwdriver and pass it across the sensor the coil fires every time I do that. When I install the sensor it doesn't fire.
Since the original sensor was damaged, how likely is the gear butchered bad enough not to work?

I am getting ready to LS swap this thing, and I only need it to run long enough to back it up the driveway into the garage. It's too steep to push it.

 

[Schurkey]

I can make the coil fire if I take the sensor out and take a screwdriver and pass it across the sensor the coil fires every time I do that.

That seems to verify the rest of the ignition system. Good.

When I install the sensor it doesn't fire.
Since the original sensor was damaged, how likely is the gear butchered bad enough not to work?

I wouldn't expect that...but clearly something is wrong with the sensor/reluctor system, and the sensor seems to work. So that leaves the reluctor.

 

[Kevmore007]

This looks wrong.
I have it running now. Part was 23 bucks and it runs like new again.

You must be registered for see images attach

 

[Schurkey]

 

[JerrysGuzzi]

50 at prime, or 50 when running? Low 50s is ok when running, not enough during the prime cycle.


Did you ever check for spark? Did you replace these parts before or after you noticed there was no RPM showing?


Instrument cluster tach? Have you verified ALL the fuses? Assured that the molded-plastic connectors at the module and ignition coil were snapped properly into place--not loose, no bent pins?

Good chance this is a failed crank sensor/reluctor, or crank sensor wire harness. MAYBE a failed ECM, but not likely.

Verify that the computer has no RPM signal with a scan tool.

No RPM signal = no spark, no injector pulses.

Verify that the computer has no RPM signal with a scan tool. How does a new old person to this sight check for RPM when the engine won't fire. I could tell someone about my first experience with this, maybe something there? March 2024 then again two weeks after new fuel pump and first of May. I'm going back to settings. another day.