Gripenfelter

I jumped on the dyno today and discovered I have a misfire at 5200 rpm.

Kind of fixes itself after that but its constantly there right at 5200rpm. I made 5 runs and everytime it was at 5200rpm.

Is this the opti?

I have a surge at idle sometimes too.

madwolf

Does it look like a dip? But yes, I would say 95% it's your opti.

Gripenfelter

Yes its a dip followed by popping from the exhaust.

I did bleed my cooling system a few days ago after which the surge at idle started.

If it is the opti, should I get a complete new one or just cap and rotor?

madwolf

Just get a new one. I know it will be expensive because it's a non vented unit (unless you converted over), but it's not worth changing just the cap and rotor in my opinion, unless you have scary prices for these in Canada.

Gripenfelter

Thanx dude.

So you would say most probably opti. Not anything else?

madwolf

I've seen it many times on dyno sheets and it was always the opti.

Gripenfelter

Do you mind if I email you a pic of the graph when I get home? It did it on 5 runs at 5200rpm.

You can see a dip in the rpm band, horsepower, and torque followed by the air fuel ratio curve going fat.

Could the opti also cause the surge at idle?

madwolf

Yea, the opti can cause a surge at idle and lower rpm as well as high rpm as in your case. You can email me the graph if you want.

LT1Squirrel

ouch..buying an unvented opti in canadia....thats like 23 grand

Gripenfelter

Yeah I might have to sell one of my sled dogs and my Mario Lemieux hockey stick for one.