Moisture problems??

[fpb1529]

I own a 99 Suburban 1500, 2wd 132,000 miles. I replaced the distributor cap a few months ago because I noticed it ran rough when the roads were wet or their was high humidity, it ran fine for a few months. Yesterday it was difficult to start and ran rough (sputtering) for about 10 miles then ran fine. This occured after a bad rain storm had passed however the roads were dry. Any help would be appreciated

[Jimmiee]

Welcome to the Club. How about the wires? Old wires break down when they get wet. That would be the next logical step.

[2COR517]

Wires are the likely cause. Get nice wires from NAPA. The premium Blue Max by Belden. They're like $75 for the Vortec. Also, put your distributor cap off again, and make sure the two vents are clear. There's one on the left side, about 7 o'clock i think. The other is on the right, in the dropped down section. I used a rubber tipped blow gun.

[tattooed4life]

I was told by a mechanic here in town to knock the screens out the vents, change the wires to good ones, and replace the cap. After doing all of this with good quality delco parts (cap&rotor) my truck never acts up in the rain. Good Luck

[2COR517]

I couldn't see/find the screens.

[fpb1529]

I took the cap off and found a small nick on the edge, I believe moisture could get inside. It looks like the button swung around and damaged it. Any idea why this happend?

[Jimmiee]

Button??? Do you mean the rotor?

[fpb1529]

Yes, I am sorry the rotor. I went ahead and bought a new cap and rotor at Auto Zone. I wanted to see if this one got damaged before I paid more for an AC Delco set. My plug wires were replaced about two years ago with the Belden wires. If this does not work I am going to put new wires and plugs on it, then if that fails I will just have to take it to a mechanic.

[2COR517]

If the rotor hit the cap, it may have been installed incorrectly. Also a possibility is that the cap wasn't seated well. Which could allow lots of moisture underneath. The screw bosses on the plastic dist base have a tendency to break/strip so the cap might be flopping around a little.