Chevy & GMC Vans

Hello All; I recently bought a '98 Safari. just yesterday I started it to warm it up, and the belt or alternator started squealing, so I shut it off... When I tried to start it again it would not start. It would occasionally fire but not run. I checked the belt, and it is in good shape. I went to the distributor to see if it lost spark (got spark out of the coil, and at the plugs, and seems pretty strong; bright blue spark) I have fuel at the lines going into the CSFI but am not sure what to look at now. I have a AutoXRay diagnostic tool and there were NO fault codes (stored or current).
I was wondering if there is a way to check (accurately) the TPS, AIC, MAP sensors???
Or if anyone else has had this problem I can really use some help...
thanks all

Welcome to the group, nice to have you. I too have a '98. My suggestion is look at the belt tensioner. They cost $40, easy to replace and do fail. I've replaced mine once during my long ownership. I would also check the alternator and starter as they sometimes squeal when failing.

when it was running did any dash lights stay one like the battery light, whining alternators is apparently a good sign that it's failing (at least in my cases)
also when you were attempting to restart it would the dash lights dim considerably almost to the point of going out?

Can you hear your fuel pump running when you turn the key to the run position? You will be able to hear it run for a couple of seconds once the key is turned to the run position.

thank you all for your answers, I did check the alternator tensioner, it was OK... I also am not worried about the starter, it still cranks the engine over good. I did notice that the alternator was not putting out the 14.5 volts instead it was putting out 5-7 volts. what I am trying to find out is what killed the engines ability to run. Would a blown alternator shut down the injector system??? Or should I look into the MAP sensor???
I am not that familiar with the newer vehicles with their computer controlled systems. Any help would be appreciated.

Check the ECM fuse(s). Does the fuel pump run when the key is first turned to the on position?

Yes, ALL Fuses are good, and fuel pump gives full pressure when key is turned on, gotta be something else, anybody have problems with TPC, or MAP sensors that made it where the engine would not start???

It`s not gonna be a TPS or MAP sensor. Does it still squeal when cranking? is there a burnt rubber smell? if so alternator pulley maybe locked up. Remove the belt from the tensioner and spin all the pulleys by hand, all ok?

still running into the problem of not starting, cranks fine, and I have tried pushing the gas pedal to the floor and cranking the engine. I checked the fuses and want to check the fuel pump pressure, but am unsure how to. after cranking the engine when I stop and turn the key off it acts like the engine wants to turn over for a split second, only AS I turn off the key. ANY IDEAS???

squealing stopped when I shut it off just before it would not start again. The pulley isn't locked up, but I know the alternator is fried, but even with a battery charger hooked to it, it doesn't seem to help with more battery power. Just trying to find out what is happening with the non-starting.

Do not touch the gas pedal when cranking, your van does not have a carburetor.

To check the fuel pressure, pull the engine cover, locate the valve on the fuel line and attach a fuel pressure gauge.

It may not be that easy. He hasn't indicated the year of his van, but the early ones don't have a fuel pressure test port. I had to install an adapter to test mine.

Never mind. I just saw the other thread where he stated it's a '98. Please disregard my previous post.

Try giving it a shot of starting fluid and see if it catches. If not, possible:

1. Ignition Module
2. Ignition Coil

alternator …only 5-7amps? THAT"S IT!

The van will not run without the alternator working properly. That's a cheap and easy fix. Do it and report back the good news.