2002 Astro Not Starting / Running Strange

Hoping someone can help diagnose, done a lot of work with cars but never had anything like this.

It's a 2002 Astro AWD with 55k miles.

The other day it stalled for no apparent reason, started right back up but the wife says it's "acting funny".

Yesterday she went out to start it and it wouldn't start, I checked it out and here's what it does.

It turns over quick and normal for anywhere from 2-5 seconds but with no sign of starting, and then for a split second acts like maybe it wanted to catch and start but instead it stops turning over at all and all the lights and gauges go out. This lasts for less than a second and then it goes back to turning over and repeats itself. The long you keep the key in Start position the more frequent the times where it stops and the lights go out.

I replaced the battery with a new one I had in a different car and it acts just the same way.

I can hear a whine then the key is turned on which lasts <5 seconds, and I'm guessing is the fuel pump.

Once in a while I can luck out and get it running, but once its running it doesn't idle quite right and occasionally stalls. On the other hand, once I've had it running for a couple minutes it will start back up at least 3/4 of the tries. Still doesn't start correctly, but it does start.

I've read through the forums and have some things to consider like fuel pump and TPS but hate to spend that kind of $$ and time just guessing.

Any help is appreciated.

If all else fails I guess I can do the dreaded thing and take it to the dealer.

astros suffer from clogged fuel lines if u drive with low fuel, use fuel injector cleaner and dont let get below a quarter tank. the other thing is the spark plugs. they are easy to change except one. if u take it to a mechanic. watch him because they like to avoid changing it.

Thanks for the advice.

I changed the plugs (PITA), put in injector cleaner, and changed the fuel filter.

However, couldn't get it started to get the new fuel to run through the injectors.

Hadn't thought of checking it before but the air filter was very clogged. Battery was dead by the time I found that. Will get a new filter today and have battery charged to try again tonight.

Put the clean air filter in and a fresh battery and still can't
get it to start to see if the injector cleaner helps.

I think I'm going to figure out how to check fuel pressure next....

Had the same exact problem, friend mechanic said to wait till it was dark and spray some water with a hose under the hood around the plug wires and distributor and then have somebody try and start it and watch under the hood, What a light show!! Seems GM's plug wires are pretty much worthless after 36K, changed the wires with some life time guarantee ones from NAPA and also did a new cap and rotor at the same time and I swear it runs better than when we brought it home new!!

Thanks for the tip. I haven't had the time yet to figure out what
type of fuel pressure gauge/fitting I need to test the fuel pressure,
so maybe I'll do some checking on the ignition first instead.

I'll let you know how it goes.....

I went at it with a timing light and it behaved really strange. Some cyls would light up sporatically, some not at all, and #5 would light up so often it must have been going at every cyl position.

When I disconnected the wire to #5 then it would crank without hesitating and dying out so I figured at that point there must be a
short in the dist cap.

So I got a new one and problem solved.

Thanks for the tips you guys gave.