: Simple spark plug question - Northstar "tune up"

12-22-13, 01:14 AM
Just want to get a feel for what people think of plugs for the Northstar engine. I'm pretty well aware that on the 4.x engines, it's of no use to use anything fancy, just the Delco platinum plugs. This hold true for the N*? I only ask because this is my second N*, and both have a minor tendency to misfire when it's rained or very damp, so I'm mulling on tune-up products...

12-22-13, 01:23 AM
Use only the correct AC Delco plug in the Northstar. They tend to foul anything else.

12-22-13, 10:40 AM
:yeah: A/C Delco 41-950's for your pre-2000 Northstar.

both have a minor tendency to misfire when it's rained or very damp
That is not due to the plugs.

12-22-13, 11:41 AM
For the 1996, (or any pre-2000 Northstar) with waste spark ignition, the condition and cleanliness of the ICM, connectors, coils and base contacts and plug wires is the determining factor in performance and occasional missing. ANY moisture that collects or condenses on any of those ignition components will cause a nagging miss. Squeaky clean is the answer, because condensing moisture simply LOVES dirt and scum in an ignition system.

AC Delco #41-950 plugs for pre-2000 engines. AC Delco plug wiresets seem to have the best-fitting boots.

Google "gm waste spark ignition systyem". Know that Northstars do NOT like cutesy multiple-electrode boutique spark plugs.

Use this waste spark diagram to properly connect the coil towers, wires, and plugs - make sure that the ICM ground cable is perfect and tight, clean terminals.

12-22-13, 12:50 PM
Cool thanks. Yeah, I understand what waste spark is...each coil fires both of its plugs every cycle. Guess it was too expensive to have 8 coils LOL. The cleanliness issue certainly makes sense. I'll do the cleaning. These things are simply great for that kind of job


I've gone through many of them :-P.