HI Guys,
My truck pretty much sat for several years, before my son and I did a bunch of work on it and it's been running great, with one exception. Sometimes when it's very wet and humid outside, it will have an intermittent miss. Would the CPS be the first place to start looking for the cause?

Thanks

 

[QUOTE=Stymied1;19795358]HI Guys,
My truck pretty much sat for several years, before my son and I did a bunch of work on it and it's been running great, with one exception. Sometimes when it's very wet and humid outside, it will have an intermittent miss. Would the CPS be the first place to start looking for the cause?

You could put in a new CPS (OEM only!). If it doesn't address the prob, at least you now have a spare for when, not if.

That being said: when you mention wet/humid, that raises an Achilles heel issue with these rigs. Specifically water leaking down driver's side pillar and dripping right on top off all sorts of wiring, fuse box, GEM, and if Murphy is lurking around - right on the PCM. The issue is the long term corrosion build-up on said components - especially the fuse box, which is the traffic cop of nearly all things electrical. When a new source of water/high humidity is introduced, random/intermittent shorts emerge and all sorts of hilarity ensues. I would not be surprised if a control signal from PCM gets disrupted by this issue.

Example: Live in northern Maine. Wintertime and truck is at airport for three weeks (for work travel). Snow builds up. Big warm spell/rain move in, melt snow right on the roof. According to the airport people, my truck honked itself to death (battery depletion). Nearly everyone here has some sort of "hilarity" involving this issue. Now I tore open the fuse box as part of sorting my problems out and it was clear that long term corrosion was bridging bus bars, allowing a pathway for short-circuiting when water sneaks in.

So although the miss could be something else, it could be an early warning indicator that you are reaching a critical mass on the long term effects of water getting all over the electricals. "Gremlins" is a common reference on this forum regarding this particular issue.

 

Moisture getting into the CPS and connections can/will cause hi-cups and/or shut downs. Take the CPS out and clean it up. Clean up the connection. Use Dielectric Grease to seal everything up. Look at the wires for cracking or chafing.

 

Thanks for the knowledge guys.

 

Great advice above. If the problem is water intrusion to the fuse panel the fix is usually a new windshield seal. May as well do the glass imo.

Another possible water intrusion spot is the IDM, behind the DS fender. But that is often a sudden tragedy, not a long term issue.

Does it have any codes? Could help narrow down the issue.