Car normally runs fine in good weather. When it gets rainy and stays wet/humid it runs poorly. -- Skips, backfires, won't respond to the gas pedal, etc.

Any ideas???

Thanks,
Mike

These cars are prone to catch the flu too easily. Next season, take it to have its flu shots. In the meantime...any general OTC cold remedy will do. (couldn't resist)

You can also check the distributor cap and spark plugs wiring...water in the area will help cracked insulation to do its evil thing...arcing.

Beno

That would be a good trick, let me know if you find any problems with the distributor! Seriously, with DIS, water can cause some problems. I had a small crack in one of my ignition coils that would cause it to run very badly at the slightest sign of water. I'd check the DIS brick and its' connections first. Water could also be getting into the wires and plugs at the plug in points.

The '87 4-cyl has an electronic ignition, no distributer.

I have a similar setup ('87 SE, 4cyl auto), but have never experienced this problem. So all I can do is guess. The first thing to do is check for trouble codes. If the check engine light comes on when the car is acting up, then chances are one (or more) of the engine sensors is getting wet.

If there are no trouble codes, then there could be moisture getting into your ignition system. Maybe water is getting into the electrical connectors that plug into the ignition module. You can pull off the connectors and check for moisture and/or corroded contacts. While you're at it, maybe pull off the coil packs and see if the tabs that plug into the ignition module are wet or corroded. Also check the spark plug wire connectors. Corrosion will need to be cleaned off. Water can be soaked up with Q-tips, paper towels, whatever. After the connections are dry, slather on some dialectric grease to keep moisture out.

And last but not least, check your spark plug wires for any cracks in the insulation.

(edited for speeling )

[This message has been edited by Blacktree (edited 02-13-2004).]

Yep, that's kinda what I've been thinking. Seems that every time things start running flakey in this car it has to do with the coil packs. Problem is my son is driving the car, he's going to school about 300 miles away and isn't real handy with the wrenches yet. I may end up going over there and checking it out and was thinking I'd pick up coil packs from the Pontiac dealer before leaving the house.....

Maybe I'll have him get a new set of plug wires and ensure the connections at the coil packs are nice and dry first though.

Thanks for the info. Any more suggestions would be most welcome.

Mike

I would definitely stay with GM coils. They should run about $45 apiece, before tax. I've read numerous strings with mostly negative reviews of aftermarket parts like these.
The DIS is really a great setup for what is. Super simple, no moving parts. But it is expensive. You could actually carry an entire spare brick in the trunk, provided you have about a lot of money lying around. At about $135.00 for the ignition module, about $90 for coils, and another$30 for the spark sensor, you'd have $250-$260 tied up in it. Add decent plug wires and plugs and your card oughtta be smokin!

Here is a simple test that he can perform to check the plug wires. After dark start the motor and then take a spray bottle full of water and spray the plug wires and see if he gets a light show ( arcing wires) . If they're bad he can easily change them.

It could be water in the ignition easy enough. Don't overlook C500 what is constantly getting drown.

You can save a bunch on DIS by going to salvage yards. FWD cars with this engine are common. It is pretty unusual for a DIS module to croak. Coils hold up fairly well as long as they are good ones. Don't bother with "performance" coils, especially accel. You don't need anything but stock coils for this. Often when an OE coil fails, it did so because one or more plugs or plugwires are bad.

If you don't have the metal shield between the coils and module... get one. Read the DIS article in my cave. A mising shield causes multiple problems. You may have to go to yards for it. in what case just get 2-3 whole bricks.

After checking grounds and battery cables... I would start with new plug wires, cleaning all the terminals on the brick (all, not just coil posts) and cleaning C500.

When you install the plug wires. get some cotton swabs and put a little dielectric up in the top of the boots. especially coil boots. Also coat the tips of the coil towers. Be careful... too much dielectric can make tight boots push off.

You can also coat all the other module terminals with a light film of dielectric. (The crank sensor terminals should be packed with dielectric. The actual sensor part not the module. packing the module hole just wastes and makes a mess.

------------------
Edison Carter: When did the News become Entertainment?
Murray: Since it was invented.

The Ogre's Fiero Cave (It's also at the top of every forum page...)

What cars should I be looking for at the junkyard to get DIS components from???

look at the motor replacement article in my cave. All the R and I think the U vin engines use the same brick. (I think the same list is linked to the DIS article. don't remember...)