2k GM missing under light load in od

[BadAssRX-7]

ok my Dad is bugging me to death about his 2000 GM. He says when in o.d. and going up a hill (light load) that the car has a misfire, lights up some kinda temp light on the dash but no CEL. He changed the plugs and said it ran good for about 2 weeks then started back again. He asked me to find the ohm specs for the COP but google has failed me for the stock COP's. From what i have read it seams like replacing the boots and springs and a good dielectric greasing has helped alot of people.So I told him to do that but if anybody has the stock COP ohm specs id love to have that just to shut him up.

[91waggin]

I had the same problem on an 01. Replaced plugs and the wires (going between the COP module and the plugs) and it fixed it. Wiresets aren't that expensive for these.

Also, testing the coil packs will only give you static resistance, which means it won't tell you the whole story. Do a standard tuneup with plugs and wires first.

[Merc3517]

Let me tell you a little story. I have a 95 and I know it is different ( I don't have the COP's) but I believe the idea applies. I was cleaning my engine and I disconnected a plug wire. after I was done I started driving the car and had a miss just as you had explained. I thought maybe I knocked a vacuum line off and to no avail I searched the vacuum leak. Ended up being the plug wire I pulled. When I pulled it off part of the boot broke off without me realizing and to my knowledge was grounding my spark before the plug on the side of the head because of the broke boot. A new set of wires fixed this.

Moral of the story is that when the plugs were changed on your dads car I would bet the boots were stressed and cracked causing the same thing to happen. I would almost guarantee that's the problem and as stated above it is fairly inexpensive to change the boots and springs on these cars.