So my 96 f250 is having some issues. For awhile there I would be driving around and all of a sudden the "wait to Start" light would come on randomly and cycle the glow plugs and kill motor for a second. Rarely stalled but did lose everything. So now it is getting worse. It stalled and won't start and the "wait to start" light wont turn on when I cycle the key. So upon being towed home I stopped at the auto parts store. Decided since the check engine light was finally on I would try to possibly get a code. No Code but as soon as I hit "read codes" the "wait to start" light kicked on and it started right up. So i thought cool lets get it home. Got it home and it quit again. This time I had to get it up my driveway so I got under the hood and wiggled the plug to the PCM on the firewall and sure enough started just fine after that. Think the PCM is going bad or is it common to have a bad connection there?

 

It's possible the PCM is bad, but if you just wiggled the connection and it started fine, I'd bet it's just the connection. Did you try tightening the bolt that holds the connector in place?

If not, try pulling the connector and seeing what kind of condition the pins are in. If they look good, spread a little dielectric grease on them and make sure the bolt is good and tight when you reconnect it.

If they appear to be corroded, you might get by for a while with an electrical plug cleaner and dielectric grease, but I would be looking into buying the stuff you need to replace the pin connections. The cleaner I use is made by CRC- it's called electronic cleaner or electronic contact cleaner or something like that- it works really well. Doesn't clean up corrosion but if the connector is really nasty, a good shot of the cleaner helps provide a good connection to get me by until I can replace the plug.

Give that a try and see what happens. You may also want to check all the other electrical connections you find just to make sure they're good and tight.

Edit- It just occured to me that the PCM and ECU are not the same thing [haha!] so you won't be looking for a bolt to hold the connection together. It should just be a quick connector.

 

Actually it does have bolt connecting it. Hopefully I can fix it by cleaning it. Cant afford a PCM right now.

 

Oh... then either we're confusing each other or I'm just confusing myself....

Either way, let us know what you find out.

 

Will do. I actually picked up the cleaner and dielectric grease earlier today!