I have 2 Chevy Astro cargo vans, a 1999 and a 2000. Both of them give me no start problems particularly when it’s damp out such as aftar a rain storm. I’ve replaced distributors, caps, rotors, fuel pumps, and crank positioning sensors. When it leaves the shop all is good until the next time it gets damp again. I am begining to wonder if it is just subsiding not because od the particular repair but rather just the fact that the van sat in the shop for a few days.Is there any known problem with these vans related to moisture?
I have seen many false paths taken when the customer insists the condition is weather related,it seldom is. Now a blast from a car wash wand OK, you could have a problem.
It seems very consistent though. If they sit outside and it rains, they don’t start. If they get parked inside, they start. ??? Any other ideas as to what could be causing the no start then?
Have the spark plugs and spark plug wires been changed recently? One diagnostic test is to run the engine in the dark and see if you have a light show with arcing wires. Also the mechanic can mist the wires with water and see if the ‘no start’ problem shows itself. If the spark plug wires have not been replaced recently, I would start there.
Hope this helps.
I have had the exact same problem! ( 99 Astro )
It’s been a long road. Still not there yet. Cold wet day, haven’t used the truck for a few
days: try to start - cranks GREAT! No start - wait, there’s a burble! Crank crank crank - another burble! Burble burble burble! After maybe 10 minutes of this, it suddenly catches and starts.
I recently sat down and tried to troubleshoot this for real.
It is NOT ignition. There is good spark.
There is good fuel pressure, 60PSI at the rail.
An oscilloscope shows that there are NO pulses being sent to the fuel injectors
( Wait, there’s a pulse! And a Burble! Occasionally. )
Oscilloscope and OBDII scanner show that pretty much everything a child could want to start this car, is present.
So I punted, and replaced the ECU. No difference :(.
I replaced the CMP ( Camshaft Position Sensor ) and it started instantly - Vroom!
A few days later, the no-start was back :(.
I had noticed a patina of rust particles on the old CMP. The top of the distributor central shaft was rusty, and there is a bit of rust here and there. I cleaned it somewhat when I replaced the CMP, but I fear it has gotten dirty again. I specifically suspect the CMP because it is the main timing signal ( along with the CKP ) that the ECU uses to output fuel injection pulses. And the no-start seems to be due to NO fuel injection pulses. If there was a problem with the air measuring stuff, I’d expect to see pulses that were too short or too long, but still pulses.
I am going to try cleaning the cmp and reluctor wheel to a surgical standard. I will also buff the rust off the top of the distributor shaft, and paint it.
Had same problem with 98 gmc k1500. Would not start on rainy or moist days. Dealership replaced crank sensor and plugs thought they fixed it “not”. After several weeks of nearly loosing my mind I decided to change the plug wire’s ,distributor cap,and rotor button ,its cranked everytime since. I feel like it was the wire’s, but was one of the three.
These caps a rotors are known to misfire right out of the box on some cheap aftermarket ones. I would try a new cap, and rotor from AC Delco or Delphi. Then make sure all the metal dust particles is cleaned out of the distributor. Lastly, and the most important thing is the two vent screens at the bottom of the distributor clog up with metal dust from the wear of the old caps and rotors contacts. This causes moisture not to escape. I think most mechanics pull the screens out and throw them away, but at least they need cleaned.
Went out today to try cleaning the distributor. Blew out the distributor with compressed air, cleaned everything I could get to with Q-tips and lacquer thinner, washed the cap & rotor in an ultrasonic cleaner, stripped the rust off the end of the central shaft and painted it. When everything was surgically clean, I put it all back together.
The truck started instantly.
- Jerry Kaidor
WOW I have been chasing the same problem on my 99 with 157K on it since Christmas. Replaced cap, rotor, plugs, wires, and coil. Everything was fine until I buttoned it all up and came out the next day, cranks but not start. Next step was to replace the crank sensor, then the cam sensor, still nothing. Maybe its the ignition module, took it out and had it checked at AutoZone, no problem here. OK, got gas, so has to be no spark, just for kicks yesterday I just disconnected the NEW coil and pluged in the old one, vroooom, it worked. My brand new coil from AZ took a sh#!. All that money for crank and cam sensors spent for nothing! Taking the new coil back today!
I have an 02 astro that would not start after a rain once it cooled off. I replaced cap, rotor, changed plugs, checked ignition coil and ran a new ground to a non aluminum location as someone suggested. No real results. Next, I noticed some water in the engine compartment after a rain, so I started weather stripping. First at the bottom of the windshield (That may not have been necessary.) Then on the lower edge of the grill pan below the windshield and around the corners on each side. Still not enough to do the trick. Then I ran another band of weather stripping underneath the weather stripping under the hood to give it more thickness. That has worked except for a couple of really drenching wind blown downpours.
Just because of several coincidences here I’ll mention that I fought a mysterious intermittent no start on an earlier model Astro van that turned out to be a ground behind the carpet within inches of the engine ‘dog house.’ The windshield would leak behind the dash and dampen the carpet padding and rust developed. Whenever the rusty connection got damp it would be difficult to start but a few days of dry weather and it would be fine. Normal testing indicated that the ignition module was failing but sanding the grounding connection cleared up the problem and resealing the windshield prevented future problems.
This is an 8 year old thread but it is likely you will still get more tips and hopefully yo’llr find the problem soon.
My update: 03-14-20 … after trying to narrow all possible thing down I replaced the distributor with a new duralastGold for 130 (included new cap/rotor and CMP.). Started pronto! BackStory: Crank/ no start. Long crank with throttle popped at times. Fuel pressure 53-58psi, Checked coil spark; seemed strong; checked again with extra coil on hand; same. Checked all spark from the cap using an extra plug wire an extra spark plug I had handy; ALL cylinders fired weak on the spark plug. Removed copper posted distributor cap that was somewhat corroded; put new cheap on on; still symptoms the same. As I first mentioned; changed the distributor to new and now it RUNS perfect.