Just got back with my 170,000 mi 5.2 liter after a 3000 mile drive to FL and back. I only had one problem, and it was not big, but could have been. After driving for about 4 hours in about 95 degree weather, with the AC on, I stopped the van to get lunch. I stopped for about 35 minutes, but when I went to start the van, no crank. The ignition key turned on all the dash lights and the windows worked... everything seemed to work, but no engine crank.

I popped the hood and connected a 12V fan and pointed the fan on the PCM module for about 5 minutes. I reached through the window and re-tried starting and it started right up. From that point on I did not use the AC, that day, or the next week. I also did NOT have any further starting problems.

I don't know why I thought the PCM might have overheated, I just did that to try something... I thought maybe under-hood temps were too high.

I looked like a genius to my 3 buddies who I was transporting to Key West that night, but I think I just lucked out.

I have never experienced anything like this before, even two months ago when the temp here at home was 95 and I had the AC on.

any ideas what would cause this behavior??? I am thinking I might have to heat up the PCM with a hair dryer and see what happens.

thx in advance

 

Hard to really say. Are you sure it wasn't going to start even if you didn't cool down the PCM? Maybe it was going to start after enough time time went by either way.

I had a similar issue with my van not starting at certain times but it was due to loose or corroded battery terminals. Everything else in the van worked but it just wasn't getting enough juice to start the van at times. When I replaced the terminals and made sure the connection was solid, my issue went away. My issue could be unrelated, but it might be worth a look.

 

Agreed that a nonrepeatable issue is hard to diagnose, but IMO a loose wire "could be" the culprit. Other issues are CPS, time for tuneup, bad engine ground, neutral safety switch, or failing relay. Without a repeatable issue though, they are all just guesses.

 

Yea, no way to know if the fan on the PCM did anything. in fact I highly doubt it.

I can unplug my computer('89) and the engine will still crank. Won't start but it will crank till the battery dies.

I'd suspect the main engine ground and or the starter connection, and if you have any white or green corrosion on the battery terminals, they top the list

 

It actually could be anything: any connector, sensor or the PCM. When I did a hot soak test my probe registered 325 - 330 underhood ( measured on top of the cc box) and 180 inside the cabin (measured in the doghouse). Those readings were taken at 100F ambient after driving for maybe an hour and a half and then parking in the shade. Obviously it can achieve temperatures even higher than those on long trips!

I'm convinced hot soak does a lot of damage to these vans. I wired my efan direct to the battery and allow it to cool the vans engine compartment down after shutoff and it has made a real difference.

 

I know it is a shot in the dark to fix a one event problem...

yes all my connections and grounds are clean and tight.

I have replaced the crank sensor last summer as preventive measure.

I have done tune up stuff in the past year, just last month replacing the plugs and wires also.

This is not a daily driver, just a long distance van that I can haul a ton of crap in when I travel. I just got back from a 2900 mile+ jaunt and averaged 12.5 MPG averaging 75 MPH up and down I-75. Not bad for a '01 B2500 work van with 4.10 rear gears and a roof top rack!

I will keep an eye on it, and repost. I am doing another 6-700 mile trip north to Cleveland area this weekend with the wife.

From the north shore of the ocean to the south shore of Lake Erie all in one week! I LUV my travel van!