89 sputters and backfires (intake)

Could really use the help... Going crazy... Im sure it could be many things BUT, My 89 XJ Idles perfect, but driving it hesitates, sputters and at higher speed when you let of the gas it sometime (more than less) backfires through the intake.. It was horrible the other day, and i parked it, then todau i took my uncle down the road to show him, and it acted 10 times better, but still not right.. it does this sometimes its horrble, and other times just a nuisance. any info would be much appreciated, thanks guys.

Check the tps first and make sure its within range.

Please excuse my ignorance, but how do i test it?

Follow this link. The instructions are at the bottom of the page.

http://www.naxja.org/forum/showthread.php?t=75844

Check the EGR system.