Sounds electrical to me! Best thing to do is find a warm dry day when it will start just fine once it does mist the electrical components with water. Go aroundm the spark plugs. Plug wires and keep misting. When the vehicle hesitates youve found the problem part.
Or you can pop hood on a night and run it in the dark no lights or anything and look for spark that is escaping.
June, 16, 2010 AT 7:44 AM
Had similar situation with my '94.
Pull the doghouse (interior engine cover between front seats) and replace distributor cap and rotor [I was told my '94 did NOT have a cap and rotor!]).
Done (a little time, a few [very few] dollars, and you're back on the road again).
June, 16, 2010 AT 8:54 AM
(Copied from other forums)
1. Well, it turned out to be moisture in the PCM (Powertrain Control Module). When thinking back over the symptoms, I kept coming back to the fact that it had been cold and damp the entire time I was having the problem. I had already checked the distributor for moisture, and there was none. After cranking the van in darkness I was certain that the plugs/wires weren't arcing. My buddy said " maybe the computer is wet and shorting out". I checked the PCM and saw a gap between the two halves of the plastic casing. I got my wife's electric blow dryer and turned it on the PCM for a few minutes. When I turned the key it fired right up. Now I've covered the gap in the box with electrical tape to hold out the moisture. The van has been starting and running fine for the last several days. Hopefully, that's the end of it. I just thought I'd post the solution in case anyone runs into a similar problem.
2. I had this exact problem with my 98 Astro Van, for a number of years. When it was very damp outside (lots of dew or condensation) the Van wouldn't start. When it was dry, it would start well. --&Amp; gt; Eventually I found the problem. The ignition coil was defective, i.E. It had a crack in the coil case. When it was damp out, the coil case would become wet, and the electricity would short (arc) to the coil frame. Hence, no electricity would flow into the distributor, or plugs, etc. When it is dry, it is harder for it to short to ground, so the cracked coil will work (somewhat). To check for this, try the following when it won't start. Lift your engine cover off and locate the coil. Make sure the wire (coil to the distributor) is firmly connected at both ends. Turn the key and watch the coil. If you see blue-white electrical arcing, you have a bad coil. I changed mine over a year ago, I have never had this problem since. Note: For this specific problem, change your coil before you spend money on plugs, wires, etc.
3. 1999 Astro had always started on first crank. My problem started in Jan '09. One wet morning it wouldn't start. It fired/misfired a few times but no start. Didn't have time to fool with it for a couple days. Weather changed to cold and dry. Started like a champ. Next wet weather the same thing happened.
Put it in the shop for a tune-up including cap and rotor. It always started after that but a new problem showed up a couple of weeks later. During damp weather the engine would miss, usually at about 2,000-2,500 rpm. Sometimes minor - sometimes it would barely run. Back to the shop for cap & rotor. Ran OK (a miss every now and then) for a few weeks then started missing more frequently. Back to the shop. This went on for a year. Eventually replaced coil, MAFS, plug wires, and about 5 cap & rotors. Each time it was worked on it would run OK for a little while then start missing badly again.
There were times when the van ran perfectly. When humidity was down in the 20% range it ran like a champ. Also, if I drove it and got the engine hot, then parked it for an hour, it would run great.
Several weeks ago I had some work done on another vehicle at a different shop. I was very impressed with the young shop foreman/mechanic and talked to him about the van. He said bring it in and he would fix it, period.
And he did.
Took him the van during wet weather. On the scope the coil was strong. He put each plug lead on the scope. At idle it was fine. At about 2,000 rpm one plug would totally lose fire and the adjacent plug get both pulses. The cap and rotor were new and looked fine. He uses a diagnostic service who provided the answer. Crappy aftermarket parts!
The root of the problem is in the " crossfire" type cap - in some aftermarket caps " the conductive bands are routed too close to the plug wire towers". This results in arcing within the plastic of the distributor cap. The aftermarket caps I'd received were close to working OK. Adding damp conditions put them in failure mode.
The solution? An OE cap and rotor. From the moment the OE cap went on the Astro has run perfectly! Starts up at a tap of the key and not one single miss. Rain or shine, not a problem.
I've read on other forums where the problem was solved with a complete new OE distributor. I'm betting that just the OE cap would have had the same results.
Hope this helps someone else.
4. It would crank until the cows came home and not start if left out in the rain. Found one of the distributor cap hold down screws was corroded to the point of breaking the threaded hole in the PLASTIC distributor housing and not sealing between cap and housing - $$$ later for a distributor, new cap, things were good for a couple of months. Came back again - this time put plug wires on, helped but did not cure it. As we were at around 150K miles, I changed plugs, 2nd time I think in 150 K miles. As much as I don't like Champion plugs, I couldn't get the AC's so put the Champions in - now have 167K on it and it starts anywhere, anytime.
5. Remember the basics, do you have spark, air, fuel, you said spark at the distributer, did you pull a plug wire and check for spark at the plug, install a plug in the boot and ground the side and see if you have a good strong spark, next install a fuel pressure guage, make sure the pressure is in specs, then when the key is switched on and you try cranking spray some carb cleaner into the air intake if it coughs or starts and dies you have a injector problem if the fuel pressure is good. Check the ingnition timeing, see if you can find a timeing mark and set the no 1 cylinder to tdc, then pull your distributor capand check that the rotor is at no 1 position if not rotate the engine 1 revolution and see if it is at no 1 now if not did it rotate at all, you might have jumped time.