Knock at 4k-6k

[bcjjones]

Started logging my new 92 talon tsi once I started increasing boost. From what I was told everythings is stock. Raised the boost to about 13-14 psi. Pretty normal numbers on the log from what I understand but around 4k through 6k I have pretty bad knock numbers. Highest being about 45.

I know i have a random misfire on cylinder 2 due to a bad injector with too much resistance. Doesnt misfire everytime but does misfire. Could this cause the knock reading?

Like i said all the other numbers look normal from what I understand and no knock at all during the lower rpms. Turbo spools and hits 13 psi before 4k and the starts to taper down

 

[jcarmichael]

if your injectors not firing your going to be running lean, most knock my car ever sees when its poorly tunes is 5 percent. what logger are you using? if your getting serious knock your timing could be to retard or you could have a bad knock sensor but usually that would cause you to get knock at other times.

 

[kris_stewart10]

Change that injector. Or rewire the connector it has happened to me. The worst thing is having a miss because of an injector after wasting time checking for boost leaks or other problems. Just change the knock sensor and check your injectors. Then see where it goes from there.

 

[bcjjones]

Yea this friday im just going to upgrade to some 550's and a walboro 190. Ill see where that gets me. Im logging with a Palm Pilot III with MMCD

Also another thing i forgot to add is the guy I bought it from "said" it was tuned to run on Premium only. Due to the fact that its completely stock I didnt beleive him. Not even a MBC was on it when I bought it. No reason to tune for completely stock correct?

If it were tuned for Premium only would putting regular unleaded cause knock? Just for future reference.
One more thing i wanted to add is that while adjusting the MBC I accidently set it at 20 psi and didnt get fuel cut at all. Is that at all normal?

 

[jcarmichael]

our cars require premium if you don't wanna pay the extra 20 cents a gal. for that go to 89 but I only run premium and have since my car was completely stock. pretty sure it says that in the owners manual as well. Yea it could cause knock its a lower grade gas. also keep it away from 20 even though you don't get fuel cut your over running your injectors. you want them to be around 80 percent duty cycle at 15 psi my car reads over 100 percent I usually keep mine around 13 psi or lower. Putting bigger injectors in next week though.