Car is a 00 Si with CAI, s2 manifold, dc header and tanabe exhaust. We installed a ZEX kit, purge valve and bottle heater exactly as the insturctions said, no problems. Used the 55 shot jet 3 times, two back to back and the other the next day. That was early last week. Now, his car started acting funny he said, so he removed the bottle and redid the vacuums to cancel out the ZEX box. His car is backfiring much more now, and is stumbling on acceleration. We reset the ECU, changed plugs and did a compression test. Compression was perfect across the board and the plug looked fine, just a hint of white on them. What could be wrong with the car? My guess is a fuel problem, but wouldnt backfiring indicate its too rich, and the stumbling and loss os power mean a lack of fuel? We are lost, any help is great.

 

Bump. Even a suggestion would be appreciated.

 

did you move the timing??

 

I would check your vacuum lines again. Lol, should have stuck to your turbo jk

 

Didnt touch the timing and the vacuums are right, its only 2 lines.