I have a 2002 Blazer 4door 4x4 and the other day I replaced the spark plugs and wires. The truck runs great when cold but as soon as it warms up I am getting arcing somewhere around the 5th cylinder spark plug. The truck also drops down to about 300-400 rpms when idling warm and seems to hesitate when accelerating until about 2500 rpms then it acts normal. I cant seem to locate where its arcing, any ideas/help?? I have already replaced the cap and rotor about 3k miles ago. Would the ignition coil have anything to do with the arcing?

TIA

 

When its dark out you should have no problem seeing where the spark is jumping from. You will hear it making a "snapping" sound as well.

The coil wouldnt have anything to do with the arcing, but old plug wires sure would. Get yourself a new wire set and install it.

Also are you getting any engine codes?? cause the truck should be able to compensate and hold its idle even if you took 2 plug wires right off it... You may want to get yourself a can of "CRC Sensorkleen" and clean up your sensors while changing the wireset. IAC (Idle Air Control) and MAF (Mass Air Flow)are 2 good ones to clean up.

Post engine codes if you are getting any, you can get them scanned for free at the parts shops if you dont own an OBD2 scanner.

 

Is it lopin' idle when warmed up, like at stoplights?

 

Thanks for the help! I waited until dark and found that there was a tiny hole in a plug boot causing an arc to the heat shield next to the exhaust manifold. Luckily autozone swapped the wire out since it only had ~20 miles on it..

That helped the rough idle when warm, however it still seems to be sluggish under 2k rpms. Would cleaning the MAF & IAC help this?

 

Cleaning the MAF, EGR (need new gasket before you start), and the IAC may help this condition (couldn't hurt).