P300 misfire question . . .yes i have done a search

[Red97v6Bird]

So this morning it was raining cats and dogs and hitting puddles was unavoidable. So after about 5 mins of driving the check engine light comes on and it start running pretty rough. This has happened once before it involved water as well. But after it dries and i clear the code it goes back to running fine? Unfortunately my scanner doesn't have the GM-enhanced parameters. . . .

any sugjestions are greatly appreciated i am new 2 the LT1

96 Ram Air WS6 Stock

[Joe 1320]

You have water contamination in the ignition. That's what's causing the P300 misfire code. I've had some success in pull the plug boots and using dielectric grease to seal the boots to the spark plugs and the optispark distributer. Also check all the harness connections to the coil, driver module and distributer.

[Red97v6Bird]

Thanks for the quick reply Joe. So this isn't an indicater of a bad opti then? As i said I'm new 2 the LT1 and perhaps a little paranoid. Any specific grease U recommend ?

[Joe 1320]

What it's a sign of is a breach somewhere. If sealing up all the plug boots with dielectric grease doesn't cure your problem, then it's in the harness or opti itself (which I tend to doubt) . I'll bet it's the plug wires or weather pack harness connectors. Seal them all with the grease and go see what happens. Mine used to do that right after a new opti was swapped, the grease cured the problem.

[Red97v6Bird]

First of all thanks for all the help Joe

Now for the dumb newbie question :

What the heck is the weather pack harness ?

[Joe 1320]

Each harness connection has a little urethane /silicone (whatever) gasket that is sandwiched in between the connectors to seal out moisture. A little dielectric grease on those couldn't hurt, if you find any missing then replace them. That would short out the connection anytime you hit water!