I am new here and have a question. I have a 94 Geo Tracker 1.6 SOHC, Auto, 4X4, 2dr soft top. the engine stumbles intermittently on acceleration, she makes a popping sound and acts like she isn't getting enough fuel, stumbles and hesitates. I put new E3 plugs in her (10 bucks a pop), new dist. cap and rotor button, i havent changed the coil or plug wires yet, but with what i did put on it didnt seem to help, gas mileage has also suffered. I took the egr valve off and cleaned out with carb and coke cleaner (on advice from another Tracker owner) anyone have any ideas or possible solutions?

Did you check the EGR passages through the head to exhaust manifold, the metal tube going to the intake plenium on the pass side,and the hole in upper intake to the tube. Those will give you things like that. Another thing to check might be the cat, mine stumbled in 4th gear and idle was screwy. Just changed out the cat and the difference is amazing.

I think the only engine available in the 94 2 dr Tracker was an 8v and doesn' t have the external EGR tube, only 16v has it.

Try replacing the gas/fuel filter.  found in front of the gas tank on the passenger side

The 1.6 16 valve was available in 94 Sidekicks,I have one in my 95.

Yes, beginning in 95, the 4wd Geo Trackers got a 16v engine and the 2 wd Trackers got an 8v (last year). 

I think the only engine available in the 94 2 dr Tracker was an 8v and doesn' t have the external EGR tube, only 16v has it.

Reviving this thread as a correction.  I looked at purchasing a '94  2dr, 4wd Tracker yesterday and it did have the 16v engine with the VIN code 8th digit 6.  I apologize if my statement caused any confusion.

Yes, beginning in 95, the 4wd Geo Trackers got a 16v engine and the 2 wd Trackers got an 8v (last year). 

actually, the 16V was available in the 4 door as far back as 1992. the 2 door only got it from 1994 on. there was NO 8 valve motors used in either models after 1995.