My car has been plagued with misfiring codes ever since I got my car back from the tuner (2 different shops). We are not sure why this is happening. It's pfab's log kit with the new flashpro, running on 12lbs of boost and ngk bkr8eix's. There seems to be two issues that I have. 1, the car breaks up in high rpm (7k+) and 2, when the car has been driven around town and comes to a stop/idle, I lean out really bad (a/f 17-18), thus throwing a cylinder misfire checkengine light. Today I double checked all the connections, gapping (.028, also tried .030, .032), checked injectors (ID1000's), voltmetered alternator and battery for voltage loss which was moved to trunk, but everything was perfect, 14+ volts all around and no voltage loss at fuel pump (walbro 255). I've read several articles that this may be the coil packs going out, if so, why so soon? I have a 07 with only 30k miles and only 3k of that was boosted.

I think I've done what most people would've at this point. It is either a faulty flashpro, bad tune (but with two reputable tuner shops in the pnw?), bad spark plugs (I ordered a set of Denso IK24's coming tomorrow), some other electrical anomaly that I've yet to find out, or bad coil packs which is all that's left for me to verify with another set or rsx's. I need your inputs!

 

Try a bottle of injector cleaner.....?

 

I tried octane booster. ^ I think they are similiar if not the same. It helps with breaking up in high rpms but does not help with misfires during idle.

 

I just checked the voltage at the fuel pump again and its 12.80v. The alternator and battery is 14.1v. Could a voltage difference of 1.3v create this problem? AF is 17, according to my aem wideband at idle. Also, my car has the stock returnless fuel system besides drop-in walbro 255. I have not tested fuel pressure.

 

af is 17 at idle? Thats a little lean. Again thats not alot of flow to get a great reading. How close in the DP is the meter located

 

I would try swap out coil packs with other member's car. Or for example, if it throw misfire on cyl 1, then you can try swap with diff cyl coil pack and see if that misfire follows.

 

Wideband is about 18" from turbo. Af is fine once under load, 11 wot to 14 50% throttle. Only during idle does it lean out. Still breaks up top but not anymore since I lowered boost to 10lbs.

 

You could have one bad coil, also check your grounds. Start lowering the plug gap to see if that helps.

 

Are you running a stock MAP sensor still?

 

4 bar omnibar