Firstly, i have 4agze.
Which started to misfire at topend when Wide Open Throttle.
I had recently put in a half-bottle of Pro-strength Octane Booster. My gze is running a top mount factory intercooler with no cooling scoop. Nor a hole in the bonnet.
The suspect spark plugs were from the front-cut which i checked earlier this year and had normal wear and condition.
i.e grey, brown carbon deposits on electrode. They are split fire spark plugs with a 1.1mm gap
Also im not running an Oxygen sensor at the moment.
Anyways getting to the point.
I decided to check these sparkplugs to see if that was causing the misfiring. I removed all 4 s/plugs to find that all had....
- a rusty brown deposits around electrode and the ceramic insulator. No sign of grey, brown, black or even white as you'd expect. no sign of oil or mechanical fouling.
The electrode wear was fair.
Here are the pics. (sorry about the poor picture quality as they were taken on a 0.3 megapixel digicam)
Now i know the correct gap for the 4agze is 0.8mm, but the plugs were working fine up until this misfire problem last week.
Diagnosis?
- Would this misfire be caused by the plugs fouling due to the octane booster???? (Too much octane boost?)
- Detonation (but the knock sensor never activated) Was no audible pinging.
I have been told by others that too much octane booster will foul your plugs. Is this true?
I have since replaced my plugs with NGK cooper ones with a 0.8mm gap. But i havent yet tested it at W.O.T.
Need your advice first.
WTF? Rusty brown Spark plugs.
Thu, 13 February 2003 04:41
