Exhaust is making little popping sounds (misfiring) at idle. Idle is steady.
I held a piece of paper over the muffler tip and the paper is getting sucked into the muffler when it misfires.

Feels like its making the same power but burns a little more oil and gets a little worse gas mileage. Also vacuum is a couple inches lower than normal.

When I got the car built and tuned, I was told I would probably burn the stock valves in about a year from boosting. Well its almost been a year boosting 14 psi daily and this is happening. I wanted to build up the head anyways but I want to know how far to go with the head $ wise because I may need new pistons.

Do these symptoms sound like burned stock valves/valve seals or could it be that I melted a ring or piston?

Btw when I melted a piston before (my fault) the sparkplug was getting soaked in oil, idle was not steady and the plug was fouling out ever few days. Its very different this time.

 

Stock valves shouldn't burn that easily with a good tune.

 

trust me i havent been easy on them.

but on a side note, when the car warmed up today the misfire went away completely.

Anyone else's motor run better w/ hondata when motor is warmed up?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Turbo Chris &raquo;</TD></TR><TR><TD CLASS="quote">Anyone else's motor run better w/ hondata when motor is warmed up?</TD></TR></TABLE>

Yeah, mine.

I have RC 550cc injectors and Hondata. It makes a little bit of a popping noise and has an erratic idle until warm.

 

mine was doing the same thing. when i took the engine apart , i found out that the pistons 3 chipped and all of them were melted. i really thought that it was just rings because the car still runs but it smokes when i let off the gas after getting on it. hope this helps....