What causes an exhaust sputter at idle? On my 89 TBI, for many years. I'd hear this noise that sounds like "doomph", and would sometimes see the RPM needle dip when it did this.

Then I found on the "doomph" noise, that you could hear it coming out the tail pipe and sounded like the exhaust was spitting every so often. And you could also feel it as well.

Over the years I've done all the usual tune ups a couple times over.

 

sounds like a miss, how are the plug wires?

 

Plug wires are fine. I've replaced all the usual tune up stuff at least two times: Plugs, wires, cap, rotor, coil, fuel filter, PCV valve, EGR valve, etc.

The sputters aren't steady or in time. Just every so often you can hear a "Doomph" and feel it spit out exhaust at that time.

Only other thing I can think of is I had the cat removed and the smog stuff removed and the air tube holes plugged at the manifold.

 

Bump.