Intermintant Misfire

[mbeeman350]

Have a 2005 GP Base model, 3.8 L with 112,000 miles. Engine misfires when it is warm, shut down or sits for a minute or so then restarted. So when driving at low speed cruising is is misfiring or "skipping". BUT if I turn the engine off and restart, going down the road, it starts and runs fine. This event is inconsistant. New Autolite double platium plugs with Bosch wires at 96,000 miles. Scanner says no codes!. Thanks

 

[BillBoost37]

Please swap the plugs for an Iridium or copper core. Our waste spark ignition systems eat platinums in a month or less. It's a very common issue. As for the on/off of the misfires...odd. Maybe crank sensor or ICM, even a coil. But it might be as silly as the plugs.

 

[mbeeman350]

Please swap the plugs for an Iridium or copper core. Our waste spark ignition systems eat platinums in a month or less. It's a very common issue. As for the on/off of the misfires...odd. Maybe crank sensor or ICM, even a coil. But it might be as silly as the plugs.

Thanks for the reply, pulled one plug, the contact points look clean and crisp. Even did what I call a real time scan, no codes thrown.
Runs good today...

 

[BillBoost37]

Plat plugs may not look bad. Only going on experience here. Hope it doesn't act up on ya.

 

[mbeeman350]

Just a follow up here and a thanks to Billboost37.
After 30,000 miles the Autolite dble Platinum plugs are coming at in the morning. Going back with AC Irridiums. Pulled a front plug today. The gap has changed, no crisp edges, car is idling and running poorly and gas milage has decreased. No codes detected on the 3.8 L with 125K.
Lot of threads and posts here on plugs.....should have listened!!!