I have a 92 formula 305 TPI. My mods are K&N filter, MSD6AL, SLP airfoil, SLP catback, 3:73s. WHen I floor the car I can hear a slight pinging sound sometimes. Is this knocking? It doesnt do it below or at 3000 RPMs. And I'm pretty sure it was there before some of my mods. What can cause this? How do I correct it? Its been like this threw over a year of fast driving and it still runs like new.
thanks

 

Alot of things can cause knocking..but definatly don;t let it go unchecked. it WILL do damage to your engine sooner or later.

Your timing could be too advanced.
you could be running lean.
you might need a higher octane gas, requiring 92 is not uncommon.
You might have alot of buildup in the chambers.

 

on my 86 T/A with the carb, I got the gas pinging due to my timing not set correctly.
It would only ping with hard acceleration.

------------------
Zepher
'86 Pontiac Trans Am WS6, 5 Speed:
Edelbrock 1406 Carb, Edelbrock Performer RPM 7101 Intake Manifold.
Edelbrock Open Element Air Cleaner: Flowmaster Exhaust, 160* Thermostat,
Grant GT Steering Wheel, MSD HEI Coil, Taylor 8mm Wires, Recaro Seats,
Alpine CD+Changer,Rockford & Soundstream Amps, Premier TS-1040C Subs, Polk Audio highs/mids.

WS6 Trans Am

[This message has been edited by Zepher (edited October 11, 2000).]

 

EGR valve might not be working, too, so you will have too much advance for the mixture.

 

First try running higher octane gas. If that doesnt fix it try adjusting your timing.

------------------
1983 Pontiac Firebird SE
LG4-Based Chevy 400
700R4 Tansmission
Modified 4 Barrel Q-Jet Carb
Accel Super Stock 8mm Wires
Edelbrock Pro-Flo Air Cleaner
3.23 Posi Rear
14X7" Cragar SS/T Wheels
35X4 CD/AM/FM Head Unit
100WX2 Amp
2 Pioneer 12" Subs in Custom Box

 

I had the same thing, it was the timing!!

------------------
Looking for:

87 IROC-Z L98
84 TRANS AM H.O.

 

Thanks guys. I'm going to test the car again after it gets put back together on friday morning. It' apart right now. I just ported the plenum and added an AFPR (well, its 2 day air shipped from summit.not here yet).

Want to hear something weird. I checked my timing 6months ago and it was set at 10* btdc

I never have touched it. I am the second owner, the first owner was a 58year old single woman who lived in my town. I know she didnt do it! I'm beginning to think it was tuned by the factory considering it is a 1LE. But who knows.