97 Safari stalling

[Mr_Roboto]

If you are still having problems I had a truck when I was at the chevy dealer that would just kill. It had been to 5 other dealers. I called GM tech support and had them fax over the file. It was like a book, I couldn't believe how many parts had been thrown at it, including about a dozen oxygen sensors. If someone can tell me how an oxygen sensor can make an engine stall please let me know.

While waiting for the fax I test drove it as the problem was very intermittent. I got lucky and it did it! If you watched the tach you could see it be pulled right to zero very quickly. After about half an hour poking around and taking some measurements, I found a bad ignition module. If I tapped it just the right amount in just the right spot I could kill the engine every time. There must have been a crack in the board inside the module and the right frequency of vibration must of caused an open circuit or a short to ground. I have never seen another one like this.

But you might want to tap (gently) on that ignition module
What have you got to loose.

BTW - I'm resisting the urge.... Don't get me started on incompetent techs and service departments. If you think I'm long winded as it is you don't want to read one of my rants.... I have been trying to be a good boy and have thus far resisted reading that Fram filter post.... Maybe I should do a little cutting and take some pics when I get time next month

Yeah, it sounds like the dealerships liked to "shotgun" parts at it rather then try to track the source of the real issue down. Good diagnosis is a PITA, and admittedly I've had a few electrical gremlins with mine but none thankfully that caused stalling other then the one time the alternator did go out.

[v8famvan]

PeterT, Although I have not seen many of them on the Astro/Safaris the ignition switches have been known to go bad/cut out & cause the problem as you describe. Usually when they go bad there is a few codes set, but not always......
Just something else to check/monitor.

[PeterT]

Well here is the update. Van has been fine for a few weeks. Daughter takes it out the other night and the son has left the tank under 1/4 tank again. She calls saying it is stalling again. She gets it home and I take it down to the garage and fill it up and all has been fine.
So the last time it was stalling was when the dealer had it and it was under 1/4 tank. I use to use the van as my daily ride. Now I have a company van and the kids are using it the most. Now I told them never to let it go under 1/2 a tank and both times we have had the stalling issue is when the tank has been under 1/4 tank.
So it could be a fuel pump problem. Pump over heating not been cooled by the gas in the tank?

[sfeaver]

Is it possible that the gauge isnt reading correctly? How much gas do you put in? The 97 only holds 96 liters i believe, when i'm on empty i usually put in about 80-85 or so.

Reason I mention it, my mother got towed home years ago with a quarter tank, but really it was empty. I put some gas in and it fired right up.

Hopefully its just that simple

Scott

[PeterT]

The last couple of times when I have been in it and fillled it up from 1/4 to full I have put in about $80 worth. Yesterday I was at just over 1/2 a tank and put in $35 worth and that took it to the filler neck. I keep telling the kids not to let it go under 1/2 a tank but who listens to their fathers

[dragonvan]

Peter...

Top off the tank. Next use the fuel pump to pump out between 3/4 and 7/8 the capacity of the tank (remember on a tank this size there is at least 2-3 gallons that the pump can't pick up). Now do fuel pressure and volume tests. If either or both of these is low and you have a new fuel filter it is most likely the pump. I'm not at home but one other possibility is a bad ground. The sending unit and pump on your astro may share the same ground. If the sending unit has a bad area below 1/4 tank and the ground is not good (corroded) then the pump might not be getting full voltage. The other possibility is that the hose or pulsator (whichever you have in the tank) that connects the pump to the sending unit may be leaking but I don't know why that would only cause problems below 1/4 tank.

[dragonvan]

Just an update.

I filled the tank and put in 24.191 gals. (US) tonight on my return from my trip. This means that the van will definitely run with only 3 gals. in the tank. I don't know if I want to test much lower than this though.... I'll let one of you guys continue with the experiment from here.

[peter]

Again, the fuel pump issues with my buddy happened at tank levels of 1/2 or less. But somehow, I think mebbe you should be tapping on the ignition module as mentioned earlier by Dragonvan. And jiggling the ignition switch that V8famvan mentioned.

[Smiliesafari]

dragonvan is correct about there being 3-4 gallons of unuseable gas in the tank. I've learned that from running out of gas several times when the gauge reads just below 1/4. Never been stranded though. I always have extra gas as part of my ballooning equipment.