99 Astro driving me to desparation

#1

I’ve got a 1999 Astro van with about 125K with a split personality. On a good day it fires up immediately and drives perfect all day. On a bad day it turns over but will never fire up. There doesn’t seem to be any pattern as to what is causing a good day or bad day (for example does not appear to be consistently affected either way by temp or moisture).



I took it to a garage and they said I might need a new fuel sending unit and that would cost $700 to replace but could not guarantee that would fix it. They asked me if I wanted to spend thousands of dollars in repairs because they said it could be so many different problems.



I changed the fuel sending unit myself and also changed the fuel filter. That provided entertainment in the driveway for a couple weekends - didn’t make a difference. I removed the console and engine shield and tested a spark plug and it was sparking when I turned the engine over. I tried removing the wire of the top the coil and reseating it - no difference.



How can the van sometimes be incapable of starting when it sometimes starts up immediately and perfectly???

#2

Perhaps there is a loose wire to the fuel pump or a bad ground.

The next time the engine will turn over but not fire up, spray a little starting fluid into the air intake.

If it fires up then quits, you’ll have found a fuel delivery fault.

It MAY be a bad fuel pressure regulator.

#3

All that work to change the sending unit and you didn’t change the pump?

That job should take 3hrs and the pump/sending unit what $100.00 (and I am being generous giving 3hrs.)

#4

It looks like it’s up to you to narrow the possibilities. When it doesn’t start, spray a Starting Fluid into the intake tube. If it then starts, the problem is fuel (supply, or fuel injectors). If it doesn’t start, it’s ignition/spark. You, then, troubleshoot that system more closely.