I've had this problem for a while and it seems to be getting worse.

When it rains, or even when there is heavy fog or really high humidity, my truck just won't start. It tries and tries, knocks and clangs, but nothing. I'll try for a minute, then have to leave it alone for awhile and try again later.

It kinda sounds like it's just not firing. I'll try giving it gas (either half and/or full throttle) and it sounds like it might catch for just a second. Then back to nothing.

Do you guys have ANY idea what could be causing this?

Does it sound electrical in nature, as if something is wet and needs to "dry out" before it will start? Do I need to change plugs/wires/etc.?

Thanks all!

 

Sounds like your dist cap is drawing mositure. Remove the dist cap and rotor button, spray a liberal amount of WD40 inside the cap and down on the cam sensor in the bottom of the dist. Replace the cap. The WD40 will displace any mositure but the spark will still fire thru residue that's left. If this doesn't work, I'd suggest a new dist cap and rotor.

 

Thanks. Will give it a try.

Will this just be a temporary fix, or should I be "good to go" for awhile?

 

If this is the problem, this will in all probability be a temp fix but will continue to work as long as the residue of the WD 40 remains inside the dist cap. The hold down screws may be a little lose and allowing the moisture to collect inside the cap. When you replace the cap, make sure they are not overly tight but tight.

 

You forgot to warn him what a pain it is to get to the cap on the v8's LOL.

But +1 I used to have the same thing on my old Datsun, It had a crack in the Cap

 

MAN that's no lie!
Once I got it off, I decided to go ahead and replace the danged thing. I wasn't about to keep doing that again and again!
Went ahead and replaced cap, rotor, plugs, and wires.
Good to go!

Thanks for the help, guys!
TL

 

Some things are best left as a surprise.

 

You might want to make sure the wires are in good shape too. If they're losing some of their insulating ability, being wet will make it that much easier for them to be grounding out. Maybe try cranking the engine when it's nice and dark out and see if their are any sparks shooting around where they shouldn't be. If they're on the old side, replacing them isn't a bad idea anyway. They're pretty damn critical when you think about it.

A little dielectric paste inside each boot is always a good idea too.

Make sure your plugs are in top shape too.

 

Agreed...they can be a bitch to change. I cut the handle off a phillips screwdriver to be used specifically for changing the cap and it's about a 10 minute job for me. I also bought 2 plug wire numbering kits and have one on both ends of the wires and have a printed copy of the wire locations on the dist cap in my dash. Makes it real simple to replace the wires in the new cap and not get any crossed.

 

I don't know what you guys are talking about. On my van it's easy as hell.

BW, where did you get the spark plug wire numbering kits? I've gotten some in the past and they were junk - I'd like to put good ones on all my vehicles.