Hey guys I have an Evo VI, recently there has been a misfiring issue while under boost, It idles perfectly fine though. I bought some BPR7ES spark plugs and gapped them to .024, new coil packs and leads, fuel filter, air filter, had my injectors cleaned out, and cleaned the MAF Sensor. Still is misfiring under boost in 3rd 4th and 5th gear only. I also added octane boost and injector/carb cleaner.


I am not sure what else to try, I was thinking maybe Fuel Pump is going? but wouldn't that be noticeable all the time? or maybe a Sensor somewhere, but there Is no CEL ever... its blowing my mind I cant figure this out... anyone have an idea of what could be wrong here?

oh and its pretty much bone stock.. recirculating BOV, cat exhaust, turbo timer,Boost gauge.
car pushes about 18 psi on average.


thanks.

 

Try a tighter gap. I'm using .020 with the same plugs on my evo 8. Is your tune on point? What is your timing like at peak boost? How do your plugs look?

 

Okay ill try .020 and I have not got her tuned as I need a standalone ECU , no one here can tune it as is. I just changed plugs about 3 weeks ago they are all looking okay still.

 

so I gapped down to .020 and still misfiring, something weird is going on though, right before it misfires its reading 23 psi.. ive never seen it pass 19 before

 

The issue may have something to do with the tune

 

did the car has been tuned or a stock tune? and from what is the misfire the fuel or ignition ? do you have an A/F ratio gauge? you can see if it is going lean it means fuel misfiring. and if it is reaching boost that you don't reach before maybe its a boost cut not misfiring, do you use an Manual boost controller or a boost solenoid? try using the stock spark plugs

 

Hey its a stock tune and only real mod is recirculating bov. Has a muffler but stock piping. Its not running lean at all either
Starting to think its a boost cut

 

A boost cut is very violent. It's not like miss-firings of the plugs.

 

Yah its pretty violent . Im thinking its a boost cut . Any ideas to stop it

 

are you running a manual boost control or a solenoid boost controller and check your connection if it is right or not see if all the vacuum hoses are connected

 

Dont have a boost controller it is stock and i checked them seem all connected and good

 

You'll need to adjust your map to lower boost. Is it really that hard to find a tuner by you? Where in Canada do you live? If you have logging tools you can also remote tune as an option.

 

Yah no one here will do it. Im in kelowna and ill look that up and give it a try

 

How do you monitor your engine, what gauges do you have?

 

Do u have tatrix 2.0 openport ?