Hey guys, my 92 RS has this sort of tapping/puffing noise coming from the engine, more so on the driver's side somewhere. I can't pinpoint where its coming from...It doesn't sound like valve tapping, because it is more of a puffing/tapping/ticking noise all in one. It appeared at first to be an exhaust leak at the driver's side manifold flange, but had my exhaust guy look it over and couldn't find a leak. I still think there might be one somewhere, because it is most noticible just after starting the car as it sits at idle. What else could this be? The car kinda chugs/taps/puffs along when I get on the throttle too, but I'm just not familiar with these 305 TBI engines enough to know whats normal and whats not. Help me out!

 

The is a collector valve on the emissions hoses coming off the exhaust manifold, there is one on each side, and then there is a hose that runs from one side to the other connecting the collector valve, i had my connecting hose off once and forgot to put it back on and started the car and had the same problem so i put my finger over the hole on the collector valve where the connecting hose should have been and it stopped, check that out on both sides or just check the connector hose for leaks

 

Yup, same symptoms on my old 83 firebird.
But mine was self induced. After I had replaced the manifolds with headers, I never tightened up the hose clamp on one side.