Testing a crank position sensor on a 1997 astro

Crankshaft Position (CKP) Sensors and Camshaft Positions (CMP) Sensors used on cars and trucks today come in all sorts of different shapes, sizes and configurations. All this variety might make you think that testing them is difficult and/or impossible. Well, nothing could be further from the truth since they can be easily tested with simple tools and testing techniques.
Photo 2 of 3This one belongs to a 94 Chevy Astro mini-van. This
Crank Sensor is a Pick Up Coil type that produces an Analog Signal.

This article is a primer that will help you to learn and understand the essentials of testing the Crankshaft Position Sensor (Camshaft Position Sensors too). You'll learn basic working theory, do's and don'ts, what tools to use and how to test them, and a lot of other good stuff.
How to Tell Them Apart

Another thing that can make testing the CKP and CMP Sensors seem intimidating is the fact that every make and model rolling around on pavement uses a different type of Position Sensor. For example, the Ford truck your neighbor might be driving will have a Position Sensor(s) that is (are) completely different in appearance than your GM (or Chrysler, or Honda, or Nissan or Suzuki, etc.) vehicle.

Not only that, but these sensors are called by so many different names like: Hall Effect Sensor, CKP Sensor, CMP Sensor, Pickup Coil, Magnetic Pulse Generator, Variable Reluctor, and the list goes on with a few more names. This may make it seem like every single one is tested in a different way. Well, the good news is that although they all differ from one another physically and are called so many god-knows-what names, they can usually be generalized into two basic categories: 2 wire type and 3 wire type. And this means that you only have to learn two specific testing methods.

So, before we dive into the rest of the article, I want to emphasize that the key to successfully testing and diagnosing all of the different Crank Sensors (and Cam Sensors) out there, is to know if they are either a two or three wire type! Now in case you're wondering what I mean by two and three wire types... I'm referring to the amount of wires in their connector (of course there's always an exception to every rule, but more about this later). Alright, let's jump into the next subheading and let's start learning more about this.
What does a Crankshaft (Camshaft) Position Sensor Do?

I'll start by explaining the specific role that the Crank (and Cam) Sensor play in the Electronic Ignition System of your car or truck. This info applies to whatever make and model you may be driving, so whether it's a Ford, a Chevy, a Chrysler/Dodge/Jeep, a Nissan, a Honda, a Toyota, or whatever, this primer will help.

In a nutshell, the Crankshaft Position Sensor's job is to help: 1) the Ignition System produce Spark and 2) the Fuel System to start injecting gasoline into the cylinders. All this so that the vehicle's engine will start and stay running. More specifically, the CKP Sensor produces a signal that tells the Fuel Injection Computer or the Ignition Control Module the exact position of the cylinder pistons as they come up or go down in the compression cycle. With this information the Fuel Injection Computer or the Ignition Control Module knows the exact time it has to make the Ignition Coil or Ignition Coils spark (not to mention when to start injecting fuel into the cylinders). Lastly, this signal can be either an Analog Voltage Signal of a Digital DC Voltage Signal.

Check to see if the magnet on the harmonic balancer is still in place.

The crank sensor is inside the distributor and may also be called an HEI pickup.
Disconnect wiring harness and remove the two tork head screws and lift out. Now would be a good time to replace the rotor & distributor cap if you haven't done so lately.
I hope this helps.

Try having someone pound on the bottom of the tank while your cranking if the van runs replace the pump.

First find out if your getting power to your fuel pump while cranking. If not then you must trace where the power stops and fix that. The's a way to jumper power to your fuel pump but thats only for testing purposes you still must find what's not telling the fuel pump to turn on.

does the van have a factory alarm. if it does try locking the door with key and then unlocking it. that worked on my grand national.

check the throtle position sensor(TPS) that maybe the problem.

crank shaft sen. is easy enough to change.its mounted near timing chain cover,cam sen.is somewhat harder,its in the distributor,id doubt that both are defect

HI..
Tha crank position sensor On your astro is located.
On front of the engine on timing cover, left side.
Behind the crankshaft pulley. with a connector of 3 wires.

I hope this work for you.