What is up with this?

[B-itchy Tiger]

For some strange reason, my 89 wag passed smog but only when it was tested with the K&N air filter and lid off.

As well it also still idles rough.

The timing was off but adjusted.

Just did the tfi and msd upgrade with good wires and distributer cap.

Have not re-gapped the plugs as of yet. Wanted to wait and do smog first.

Any ideas?

[davez26]

The only thing I can think of is it was running a tad to rich (borderline), so they took off the filter, and that allowed a smiggen more air to the Air/Fuel ratio and leaned it out enough to pass. Do you guys get copies of the readings? If you do, check the numbers and see if that is it.

[davez26]

The only thing I can think of is it was running a tad to rich (borderline), so they took off the filter, and that allowed a smiggen more air to the Air/Fuel ratio and leaned it out enough to pass. Do you guys get copies of the readings? If you do, check the numbers and see if that is it.

[B-itchy Tiger]

What is the best way to lean it out a bit, Rejet or adjust manually?