s13 backfires

[nismojunkie]

hey, my s13 has been backfiring lately. it pops once and it only does it when i downshift to help slow down, it doesnt do it very often, maybe 2 or 3 times a day. does anybody know what makes it do this?

[eastcoastchaos]

have you checked the timing? mine used to do that but only after i put a burly *** 3 inch exhaust with no cat. gp cars do it and shoot flames in the prosses which kicks ***. i think it burns up the valves though.

[nismojunkie]

i checked the timing before, it was good, but ill check it again now that this has started. i gutted my cat and sometimes it is really loud and sometimes it isnt. im afraid the popo will hear ti when it sounds like a shot gun and start askign questions or something.

[1991S13]

I searched (I highly recommend it!) and found a post from a while back where someone had the same question as you...

zerothread?id=44990

See if any of that helps out.

[nismojunkie]

thanks for the link, it was helpfull.

[HashiriyaS14]

Hm....

Shooting flames is generally something that happens when UPshifting. I'm not entirely sure why it would happen on downshift, although I *suppose* a rev match throttle blip could create one.

[nismojunkie]

its nto shooting otu flames, that would be pretty cool though.