HELP - M103 sudden misfiring problem
 

Hi guys, this afternoon, after my car had been sitting for like an hour, I fired her up and she started misfiring. Never happened before. After about 3 minutes, the misfiring went off. Back to normal.

After dinner today, the misfiring problem resurfaced. Drove her home and at my car park, I rev'ed the engine and held at 5000rpm for a few seconds and the problem went off. I puzzled...

My entire ignition system is about 1 year old ~ 20000 miles.

* A point to note.. I removed my airbox the other day and broke a small tube that ran from the air box to the fuel pressure regulator. The tube leading OUT from the fuel regulator was also very loose. Not sure if this caused the problem.

Would appreciate any help or input. Thank you.

Rgds

Sounds like a plugwire resistor. Easy to see with an ignition scope, even when the symptom has gone away.

103 misfire
 

that small line is a vent line for the regulator. it will not cause a running problem. if you see fuel from this line, the regulator is shot. good luck, chuck.

Steve, do you suggest I replace the ignition wire set?

Thanks once again.

Rgds

Re: 103 misfire
 

Ok, thanks porkface.

Here's a photo of the plugwire resistor. This is the piece that connects to the sparkplug. It is easily unscrewed from the wire. No need to replace the wires. They're made of steel.

http://img.eautopartscatalog.com/live/F101013373BOS.JPG

Got it... saw the part number on mine. Thanks Mike.

Rgds