Whenever it rains, my 1999 gmc savana won't start until it dries up. Someone mentioned this is a coil pack problem and that I should put di-electric grease on the contacts??? is this correct and if so, where is the ignition coil located? Thank you for the help.

What brand of distributor cap did you use? When you say it won't crank, do you mean it won't even turn over? Or just turn over and not start up?

check all wire connections for water / moisture problems as it is stopping the current from activating all the electrical items

My 99 GMC savana 1500 was chugging at like 50 60 mph and gas gauge was stuttering ..it turned out to be computer..I had it re flashed by GMC for 150 bucks ..that fixed all...hope this helps

surely ......change the wires check your sparkplugs..

It won't die when pulling the relay because it has another power path to the fuel pump through the oil pressure switch . Fuel Pump Electrical Circuits Description and Operation watch this video on fuel pump control , shows chrysler first , ford ,then gm . wait for gm an he explains the oil pressure switch . Plus when it won't start ,don't guess or theorize ! Test what's missing ? check for spark , no spark check ignition system , coil's , ignition module , crank sensor etc... has spark ,do a fuel pressure test etc... don't think computer , when it won't start does the check engine light come on with the key on run not start . If light is lit ,nothing wrong with the cumputer . If want to fix cars you really should take some automotive classes . Test don't guess .Watch some other videos crank no start videos etc...

Are you putting the wire on real good. If so, try buying a Di-Electric grease. Use this grease in the boots of the wires on both ends, also under any coil pack or on a distributor cap. This keeps moisture and rain out causing the skips,

Yes, rain or moisture can get under the plug boots, also rather it be a coil pack or distributor it can get within causing the (spark) to diffuse, meaning it splatters. It's best to buy Di-electric Grease and use it in the plug boots and if it's a coil pack, use it where the coil plug connects. This keeps the moisture out. I suppose it cuts off if you hit a puddle or if moisture gets into it, but after it sits for a minute or until dry, it will start up. The grease, you will only need a small tube, abiut $4.00.

check the batt and alt

Check all of your connections at the coil pack. Ensure that the coil packs do not have any corrosion under them were they connect into the base module or any of the connections, even plug wires. I had this same problem with my 2.2 in a 99' s-10. Pulled the coil apart, cleaned it up and and put di-electric grease on it, all better.

I have a 1997 savana and had the exact same problem....i changed everything on it, fuel pump, wires (spark plugs), distrib. cap, but nothing seemed to help...finally i went to another mechanic and changed the ignition coil and solved my problem....the ignition coil was arching....i hope this helps you...