Chevy & GMC Vans

Hey guys!Im at my wits end. Im getting that damn p300 code and can't figure out why. Whatever is wrong its causing terrible stumbling at low throttle and when i watch it in the dark my spark plugs are glowing and flickering through the ceramic, there is random arcing along the wires wherever they are close to anything and the coil is arcing where it touches those steel square plates its in-between.I have changed every component with the highest end parts from auto zone but no ac deco stuff. i have also checked all ground and cleaned both battery terminals even the corrosion that was running up the power wire. it acts like the power is trying to get out of the ignition system wherever it can except through the plug electrode. please help! I have a 2000 safari with 200,000 miles id id just do an intake manifold gaskets , power steering pump, radiator, water pump. 2 weeks later it started running crappy so i changed cap and rotor, no change so i checked the spark pug wires and found corrosion in the boots on the plug side where the intake leak had run down.i put bosch 7mm wires on and it never ran better but that only lasted a week then it started running really crapy and sum times can't get out of its own way. the check engine light has cleared itself twice now but still arcing and running like crap.

If it's still arcing and you see it, that means it's time for some AC Delco parts! Order from Rock Auto new wires, cap, rotor and coil. Another option you can try is to isolate the plug/coil wires with some spacers and insulating material and make sure they are very clean with some electrical cleaner.

Thanks for the advise. I wish i would have went online first cuz I've spent almost $200 on non ac deco stuff not realizing that it matters that much with these damn vans. I've never heard of such a thing and i went about fixing it the same way I've done every car I've ever owned but this ones really got me stumped. when i get some more funds ill start with a new ac deco cap and let ya know how it goes, that seems to be the general consensus from everyone at the dealers too but i thought they were just trying to sell me chevy parts.

Where do you see it arching? That has to be taken care of first.



I would check the gear at the bottom of the distributor, they wear out and then you get exactly what you are experiencing. You don't have to pull the distributor to check it, just the cap, then grab the rotor and twist back and forth, should be very little play. If excessive then you can pull and take a closer look. Replace the cap/rotor and it goes away for a short time then comes back, worse in high humidity. This is pretty common on the 'pancake' distributors. If so you can get a whole new billet alum distributor including cap/rotor/etc for ~$50 shipped from white performance and machine(either ebay or their website) if the gear is worn. You can also just get a new gear but for $50 complete you can't go wrong, and the last one I ordered even came with a brass cap.