Misfire at high RPM's

[PalaZejo]

Hello I have a 1g Talon Tsi. Just got a 3 inch exhaust installed this past week and noticed the first day it was misfiring at high rpms. I assumed at the increase in air flow could mean that the fuel pump could possibly not be sufficient or maybe even the fuel filter was bad. I am currently currently running 15 pounds of boost on the stock turbo. Relatively new to cars, just wanted to hear some feedback. Thanks

 

[DSMPT]

Also should do the boost leak test.

 

[tmoney20g]

Go get a set of new spark plugs, NGK BPR6ES are oem, BPR7ES are 1 range colder. You go a range colder when you start modifying the car so the electrode doesn't turn into a glow plug. Some people are now using BRxES, which is fine as well.

Don't ever assume the plugs come gapped either, get yourself a nice set of feeler gauges, and make sure the plugs are gapped no wider than .028". With a little more power, feel free to gap them smaller, in the .025" range.

You may also want to get a nice set of wires to go with these new plugs, tried and true are the Magnecor 8.5mm red wires.

 

[steve]

The tried and true wires are the stock NGK replacements, Magnecor's have proven to be expensive and subject to leaking/damage.

 

[PalaZejo]

Just put in BPR6ES brand new. I'm gonna remove them and check the gap. I'm under the impression the wires were recently replaced as well. Unaware of make. I appreciate the help. I'll keep updating while I try and get this figured out.

 

[PalaZejo]

Update: spark plugs gapped fine. Decided to upgrade the fuel pump to a walbro 255 and see if this does the trick.

 

[ThunderChild]

Make sure you're getting enough voltage output from the alt.

I ran my car the other day just on battery power ~12.5v for a few min and it was misfiring like a bi***. Once I got the front back together and the alt was powering everything, no issues.

Past that everyone else has made great suggestions and you're on the right track

 

[kodylk08]

Do the fuel pump rewire while you are at it.

 

[Calibreezgsx]

I would change the spark plug wires as well, you should be ok with those plugs at 15 psi but even with the fuel pump,re wire mod 15psi would be my limit on stock injectors to play it safe

 

[EvilGST]

I would change the spark plug wires as well, you should be ok with those plugs at 15 psi but even with the fuel pump,re wire mod 15psi would be my limit on stock injectors to play it safe

I had a buddy with the same issue. turned out it was indeed his plug wires.

 

[1990TSIAWDTALON]

I personally have had this problem and it all came down to the wires, even though they were just a couple months old and were NGK's. They were arcing to the hood. I relocated the coil to get the wires away from the hood and through on a set of no name wires and now I am boosting at 30 lbs with no misfires at all. It troubled me for six months so change out the wires even if you have to use a cheap set as a test. At least you will know unlike me.