You got a lot of good advice here..
I only worked on Astro’s when they were in warranty….when they were out of warranty the customer didn't return to the dealer; they took them to a real shop so they would get their vehicle repaired correctly...just kidding.Some info
The no start under moist conditions was a big problem with the 4.3 L Astro’s. What I was doing for a fix was spraying a good ignition sealer inside
the distributor cab, let dry, clean the ignition sealer off the electrode point(s)
install the distributor cab and spray the ignition sealer outside
the cap and try to water proof. GM said the problem was the buildup of condensation inside the distributor cap under certain conditions and made vented the distributor cab to replace the OEM cap if the customer complained of no start under moist conditions.
If I remember G.M. had a recall on the 4.3 L Astro of rerouting a wire harness between the coil and distributor it contacted a bracket near the distributor which caused a miss-fire.
Occasional problem(s) ...failure of the Front Wheel Speed sensors (ABS)
Common problems on this vehicle are failures of the Crankshaft Position Sensor, Fuel Pump, Fuel Injectors, Fuel Pressure Regulator, Distributor Cap, AWD and intake manifold gaskets leaking coolant.
SES light flashing on and off is a warning for the Catalytic Converter. Because of the engine misfire you may be hurting the Catalytic Converter.
After removing the plastic intake cover exposing the “Spider” there is a lot of oily residue on everything inside. - Normal
Spider – Rock Auto has the GB Remanufactured SCPI Fuel Injector Assembly for $159 plus $85 Core charge… SCPI was always a big problem…I would replace…
Water Pump- Check the shaft play... if its tight and you're not going to keep the van that long...maybe take the gamble... but if your luck is like mine....
Sometimes from the symptoms you have described the ECM (computer) is counting misfires at higher rpm due to some play in the timing chain. This can be repaired (sometimes) by doing the crankshaft position variation relearn. This has to done with a scan tool.
If you decide to do the water Pump with that amount of miles you should do the engine timing chain
??...Accessory drive belt (Fan belt)…. anything obvious
... ya…I know…Very important…
Gas smell may be the Fuel Pressure Regulator; you can see if it’s leaking…big problem with the Fuel Pressure Regulator’s leakingClean the intake Plenum, and check very careful for cracks and surface straightness.
DTC PO440 is an evaporative system leak and you need to find where that is…In a shop a pressurized non explosive gas with colored dye is used to find a leak. Check visually first….fuel cap seal could be the issue.
Clean the ports where the poppet valve(s) (fuel injectors) go into the intake manifold really good
.Follow instruction from the service manual closely during reassembly.
You’re lucky you can do this yourself; I can only guess the cost if you had to pay a shop to do this.
I hope this helps somewhat.
P.S…..New ones break too, I have a late 2012 Chevy 3500 HD that’s having second time issues. Lucky it’s under factory warranty and being and retired Chevy Tech I understand what the Tech is going through trying fix the truck…second time around for the same thing…I’m beginning to wonder if it’s a engineering problem. God knows how many times I had that issue when I was working…. I’m so thankful those days are over with….a customer screaming at me why I can’t fix their car that just cost them $30,000 knowing it’s an engineering problem….
Last edited by Jack fowler on Wed Mar 06, 2013 11:25 am, edited 3 times in total.