You can use WD40 (Water Displacement ) to spray water out of cracked distributors, if you want. I had plug wires that made the truck run poorly when cold and damp or rainy. On first start it ran bad, but after warming up, was find. Plug wires were allowing water in, and the spark went thataway rather than where I wanted it.
The spark plugs and distributor cap are the items to check. Inspect the dist cap for cracks, but not really a hi-statistic failure. Plug wires *can* break down over time. Just get a good replacement set and install them, especially if the problem gets better when the engine warms up.
tom

 

Thanks for all the help. I really appreciate it. I live in MN, and this last winter, the truck DID run poorly when it was cold out, but when it warmed up, it was fine. I actually posted on the subject and it was suggested to check the IAC valve. I pulled it and it looked good, but I wasn't really sure what I was looking for. The valve looked pretty simple. You can find the post here https://www.ford-trucks.com/forums/s...d.php?t=439927
I am sure that I had a tune up within the last 2 years, which did include a new set of wires. But either way, I just ordered a distributor, rotor, and plug wires, just incase I need them. I won't be working on the truck until late tonight so I wanted to make sure I had all the possible parts. I will then return what I don't use.
Could the symptom of poor cold running and then after it warms to run fine have anything to do with the distributor, or is that forsure wires? I guess I am going to check the wires as well.
Any suggestions on pulling and installing the distributor. I have been looking at the AutoZone manuals, and they say that it might have a security-type distributor hold-down bolt, can anyone confirm or deny this? I sure don't have the special wrench to take it off. Also, how tough is it to install it and to make sure its in the same position. From my understanding, you need to keep the rotor lined up with the distributor housing as well as the distributor assembly with the engine block? I might be over my head. Feel free to make suggestions. Thanks again. Also, you can find the install directions here http://www.autozone.com/servlet/UiBr...3d800b8d1b.jsp

 

I stand corrected on the distributor issue. Most of my Rangers are 4-cylinder and my personal is a 4.0. I still believe you are on the right track with a new cap and rotor.

Russ

 

I would probably just start with the easy stuff first and go with the cap and/or wires instead of the whole distributor to see if that solves the problem...

 

Can you change the rotor without removing the whole distributor? The auto parts store suggested I change cap and rotor together. Is that not true? The cap sounds like it would be easiest...

 

It's true. The rotor, just pull off, push on.

 

yeah it's pretty simple, here's a few tips to keep it super easy. Grab some masking tape and a sharpy marker. Take your time and mark on the replacement cap where the plugs are going to go (i.e. one goes here, 5 goes there) based on where they are on the old cap. This will save you a lot of time and trying to figure out "now which one of these goes where?" When marking the cap, be sure that you are holding the cap in the right orientation, as in the way that it will clip on the truck when you're done. Once the cap and rotor are replaced, you should be fine.

The hard running when wet and then going away when warmed up was probably related to the small amount of moisture that seeped in the crack when it rained and the motor was cold. Once the motor warmed up, the water boiled off, and it ran fine because of this.

 

Thats what I thought, but I will check the wires as well, but I am pretty sure there is a crack in the distributor cap. Thanks again for all the help.

 

Are you actually getting a whole new distributor? That may be overkill. Now, a new rotor and cap are certainly within reason. The cap will be held on with 2 philips head screws. It only goes back on one way. The rotor only goes on one way. I think you are supposed to put dielectric grease on the tip of the rotor -- the tip pointing out to the individual spark plug sockets in the cap. This helps prevent arcing and corrosion, I think.
If you do replace the dist, you should note which way the rotor points before you remove it. It will counter-rotate a bit as you lift the dist out, because of the drive gear pitch. Put the new one in place with the rotor pointing to about where it came out. The gears will probably let it come down only in one place and look right, so if it looks wrong, remove, move a bit and replace. The position of the dist body will determine actual spark timing, so you eyeball it, and then follow procedure on the sticker to set the timing.
An additional thing to note are the effects of defective ECT and ACT sensors. If the ECT is bad, it will not know the coolant temp, and may not enrich the mix for cold running. If the ACT is bad, it will not know the air temp coming in, and ditto. One last thing is the bi-metal that controls the pre-heat of intake air. Little vacuum switch that applys a 'door' to route the incoming air past the exhaust for preheat, and then doesn't when it gets warm enough. These all affect cold running, but if the sparkers ain't a goin' they won't matter at all.
tom

 

Thanks for all the help everyone. I pulled the cap and rotor off. The cap had cracks all over. Put the new rotor on and new cap and everything is great. I also did a wet test where I sprayed the distributor and it still started, so I hope I solved my problem. One comment, I didn't put dielectric grease on the rotor. Do I need to? Thanks again.
Chris

 

YEAH! Our system works again.
congrats Chris

Russ

 

Nope, no grease.