Got Knock? I Do. Need Help

[Boost231]

Well i just got my car back from the body shop. And now its time to look into this knock that has been kicking my but since Novemeber. Anyways i wanted to start a new thread to see if you guys can help me threw this. Alittle background info its a HotAir car but that shouldnt matter. Its a fresh motor fully built by zimmerman racing. Car has a 212/212 flat tappet cam, ported heads, billet caps, cp pistons, stock rods, etc. Im still running the Stock 87 ecm with a TT chip. I havent driven the car since jan. due to the car being at the body shop but from what i can remember it would knock on downshifts and rolling into it. It would knock when launched from a dead stop as well. The only time it wouldnt knock is if i built up 10psi or so of boost then launched and then it wouldnt knock. I have a Wideband air/fuel,EGT,Inlet air temp in the k&n and in the intake all hooked up to a powerlogger. Anyways if you guys could try to help me that would be great. I think my first step is to conferm its false. To do this im going to put C16 in it turn it on low boost and work my way up from there till it knocks. i will try downshifts, stabing it from a dead stop. On C16 im sure it shouldnt knock at anything under 15psi. I know more but lets just say for sure 15psi. so i will work my way up till it knocks. What do you all think. Please any help would be great as this thing is making me mad. im going to work on the car starting tuesday of next week. Oil pan gasket first new plugs,new o2, fresh c16. Where would you all start?

 

[Chrisk]

Why dont you record a run with PL and post it here for others to examine?
I would just record a run from a dead stop to WOT, and one while being in 3rd gear to wot. no downshift.

 

[Silver Fox]

Boost - What does Nick say?

 

[Boost231]

ChrisK
I will do that. It wont be till tuesday. Is C16 and low boost ok?



Silver Fox
nick says he cant do anything since they no longer run the stock ecm stuff. he can help if i have XFI.

 

[Chrisk]

Im no pro but from reading on here and learning, id say it wouldnt knock with c16. if it does then its false. How much knock were you seeing?

 

[Boost231]

knock nothing consistant.

 

[Boost231]

ok well ive put alittle list toghter. this is whats going to happen. Im going to try C16 and low boost and see what happens. if i still have knock im going to try the list below not in order just a brain storming session

Knock sensor to tight
Heat shield hitting accuator
ESC
torque converter bolts
motor mount bolts
inlet pipe hitting something
ECM
Loose balancer
fuel regulator
cross over hitting
alternator bearings
coil

 

[GNRick]

This suggestion might help, although I can't recall ever seeing it in print before. I solved my knock problem by fixing my vacuum leaks. Check your blms. If over 128 then you have a vacuum leak.

 

[fleebag]

blm's 128 is that at idle?
i too am getting kr issues after some upgrades

 

[GNRick]

blm's 128 is that at idle?
i too am getting kr issues after some upgrades

Yes, at idle.